The Variation of Animals and Plants under Domestication
by
Charles Darwin
Part 4 out of 10
vertically rather thick; oesophagus somewhat enlarged.
Turbits and Owls differ from each other slightly in the shape of the head;
the former have a crest, and the beak is differently curved; but they may
be here conveniently grouped together. These pretty birds, some of which
are very small, can be recognised at once by the feathers irregularly
diverging, like a frill, along the front of the neck, in the same manner,
but in a less degree, as along the back of the neck in the Jacobin. They
have the remarkable habit of continually and momentarily inflating the
upper part of the oesophagus, which causes a movement in the frill. When
the oesophagus of a dead bird is inflated, it is seen to be larger than in
other breeds, and not so distinctly separated from the crop. The Pouter
inflates both its true crop and oesophagus; the Turbit inflates in a much
less degree the oesophagus alone. The beak of the Turbit is very short,
being .28 of an inch shorter than that of the rock-pigeon, proportionally
with the size of their bodies; and in some owls brought by Mr. E. Vernon
Harcourt from Tunis, it was even shorter. The beak is vertically thicker,
and perhaps a little broader, in proportion to that of the rock-pigeon.
RACE VII. TUMBLERS. (TUMMLER, OR BURZELTAUBEN; CULBUTANTS.)
During flight, tumble backwards; body generally small; beak generally
short, sometimes excessively short and conical.
This race may be divided into four sub-races, namely, Persian, Lotan,
Common, and short-faced Tumblers. These sub-races include many varieties
which breed true. I have examined eight skeletons of various kinds of
Tumblers: excepting in one imperfect and doubtful specimen, the ribs are
only seven in number, whereas the rock-pigeon has eight ribs.
SUB-RACE 7/I. PERSIAN TUMBLERS.
I received a pair direct from Persia, from the Hon. C. Murray. They are
rather smaller birds than the wild rock-pigeon, about the size of the
common dovecote pigeon, white and mottled, slightly feathered on the feet,
with the beak just perceptibly shorter than in the rock-pigeon. H.M.
Consul, Mr. Keith Abbott, informs me that the difference in the length of
beak is so slight, that only practised Persian fanciers can distinguish
these Tumblers from the common pigeon of the country. He informs me that
they fly in flocks high up in the air and tumble well. Some of them
occasionally appear to become giddy and tumble to the ground, in which
respect they resemble some of our Tumblers.
SUB-RACE 7/II. LOTAN, OR LOWTUN: INDIAN GROUND TUMBLERS.
These birds present one of the most remarkable inherited habits or
instincts ever recorded. The specimens sent to me from Madras by Sir W.
Elliot are white, slightly feathered on the feet, with the feathers on the
head reversed; and they are rather smaller than the rock or dovecote
pigeon. The beak is proportionally only slightly shorter and rather thinner
than in the rock-pigeon. These birds when gently shaken and placed on the
ground immediately begin tumbling head over heels, and they continue thus
to tumble until taken up and soothed,--the ceremony being generally to blow
in their faces, as in recovering a person from a state of hypnotism or
mesmerism. It is asserted that they will continue to roll over till they
die, if not taken up. There is abundant evidence with respect to these
remarkable peculiarities; but what makes the case the more worthy of
attention is, that the habit has been inherited since before the year 1600,
for the breed is distinctly described in the 'Ayeen Akbery.' (5/15. English
translation by F. Gladwin 4th edition volume 1. The habit of the Lotan is
also described in the Persian treatise before alluded to, published about
100 years ago: at this date the Lotans were generally white and crested as
at present. Mr. Blyth describes these birds in 'Annals and Mag. of Nat.
Hist.' volume 14 1847 page 104; he says that they "may be seen at any of
the Calcutta bird-dealers.") Mr. Evans kept a pair in London, imported by
Captain Vigne; and he assures me that he has seen them tumble in the air,
as well as in the manner above described on the ground. Sir W. Elliot,
however, writes to me from Madras, that he is informed that they tumble
exclusively on the ground, or at a very small height above it. He also
mentions birds of another sub-variety, called the Kalmi Lotan, which begin
to roll over if only touched on the neck with a rod or wand.
SUB-RACE 7/III. COMMON ENGLISH TUMBLERS.
These birds have exactly the same habits as the Persian Tumbler, but tumble
better. The English bird is rather smaller than the Persian, and the beak
is plainly shorter. Compared with the rock-pigeon, and proportionally with
the size of body, the beak is from .15 to nearly .2 of an inch shorter, but
it is not thinner. There are several varieties of the common Tumbler,
namely, Baldheads, Beards, and Dutch Rollers. I have kept the latter alive;
they have differently shaped heads, longer necks, and are feather-footed.
They tumble to an extraordinary degree; as Mr. Brent remarks (5/16.
'Journal of Horticulture' October 22, 1861 page 76.), "Every few seconds
over they go; one, two, or three summersaults at a time. Here and there a
bird gives a very quick and rapid spin, revolving like a wheel, though they
sometimes lose their balance, and make a rather ungraceful fall, in which
they occasionally hurt themselves by striking some object." From Madras I
have received several specimens of the common Tumbler of India, differing
slightly from each other in the length of their beaks. Mr. Brent sent me a
dead specimen of a "House-tumbler" (5/17. See the account of the House-
tumblers kept at Glasgow, in the 'Cottage Gardener' 1858 page 285. Also Mr.
Brent's paper 'Journal of Horticulture' 1861 page 76.), which is a Scotch
variety, not differing in general appearance and form of beak from the
common Tumbler. Mr. Brent states that these birds generally begin to tumble
"almost as soon as they can well fly; at three months old they tumble well,
but still fly strong; at five or six months they tumble excessively; and in
the second year they mostly give up flying, on account of their tumbling so
much and so close to the ground. Some fly round with the flock, throwing a
clean summersault every few yards, till they are obliged to settle from
giddiness and exhaustion. These are called Air Tumblers, and they commonly
throw from twenty to thirty summersaults in a minute, each clear and clean.
I have one red cock that I have on two or three occasions timed by my
watch, and counted forty summersaults in the minute. Others tumble
differently. At first they throw a single summersault, then it is double,
till it becomes a continuous roll, which puts an end to flying, for if they
fly a few yards over they go, and roll till they reach the ground. Thus I
had one kill herself, and another broke his leg. Many of them turn over
only a few inches from the ground, and will tumble two or three times in
flying across their loft. These are called House-tumblers, from tumbling in
the house. The act of tumbling seems to be one over which they have no
control, an involuntary movement which they seem to try to prevent. I have
seen a bird sometimes in his struggles fly a yard or two straight upwards,
the impulse forcing him backwards while he struggles to go forwards. If
suddenly startled, or in a strange place, they seem less able to fly than
if quiet in their accustomed loft." These House-tumblers differ from the
Lotan or Ground Tumbler of India, in not requiring to be shaken in order to
begin tumbling. The breed has probably been formed merely by selecting the
best common Tumblers, though it is possible that they may have been crossed
at some former period with Lotans.
(FIGURE 23. SHORT-FACED ENGLISH TUMBLER.)
SUB-RACE 7/1V. SHORT-FACED TUMBLERS
These are marvellous birds, and are the glory and pride of many fanciers.
In their extremely short, sharp, and conical beaks, with the skin over the
nostrils but little developed, they almost depart from the type of the
Columbidae. Their heads are nearly globular and upright in front, so that
some fanciers say (5/18. J.M. Eaton 'Treatise on Pigeons' 1852 page 9.)
"the head should resemble a cherry with a barleycorn stuck in it." These
are the smallest kind of pigeons. Mr. Esquilant possessed a blue Baldhead,
two years old, which when alive weighed, before feeding-time, only 6 ounces
5 drs.; two others, each weighed 7 ounces. We have seen that a wild rock-
pigeon weighed 14 ounces 2 drs., and a Runt 34 ounces 4 drs. Short-faced
Tumblers have a remarkably erect carriage, with prominent breasts, drooping
wings, and very small feet. The length of the beak from the tip to the
feathered base was in one good bird only .4 of an inch; in a wild rock-
pigeon it was exactly double this length. As these Tumblers have shorter
bodies than the wild rock-pigeon, they ought of course to have shorter
beaks; but proportionally with the size of the body, the beak is .28 of an
inch too short. So, again, the feet of this bird were actually .45 shorter,
and proportionally .21 of an inch shorter, than the feet of the rock-
pigeon. The middle toe has only twelve or thirteen, instead of fourteen or
fifteen scutellae. The primary wing-feathers are not rarely nine instead of
ten in number. The improved short-faced Tumblers have almost lost the power
of tumbling; but there are several authentic accounts of their occasionally
tumbling. There are several sub-varieties, such as Bald-heads, Beards,
Mottles, and Almonds; the latter are remarkable from not acquiring their
perfectly-coloured plumage until they have moulted three or four times.
There is good reason to believe that most of these sub-varieties, some of
which breed truly, have arisen since the publication of Moore's treatise in
1735. (5/19. J.M. Eaton 'Treatise' edition 1858 page 76.)
Finally, in regard to the whole group of Tumblers, it is impossible to
conceive a more perfect gradation than I have now lying before me, from the
rock-pigeon, through Persian, Lotan, and common Tumblers, up to the
marvellous short-faced birds; which latter, no ornithologist, judging from
mere external structure, would place in the same genus with the rock-
pigeon. The differences between the successive steps in this series are not
greater than those which may be observed between common dovecote-pigeons
(C. livia) brought from different countries.]
RACE VIII. INDIAN FRILL-BACK.
Beak very short; feathers reversed.
[A specimen of this bird, in spirits, was sent to me from Madras by Sir W.
Elliot. It is wholly different from the Frill-back often exhibited in
England. It is a smallish bird, about the size of the common Tumbler, but
has a beak in all its proportions like our short-faced Tumblers. The beak,
measured from the tip to the feathered base, was only .46 of an inch in
length. The feathers over the whole body are reversed or curl backwards.
Had this bird occurred in Europe, I should have thought it only a monstrous
variety of our improved Tumbler: but as short-faced Tumblers are not known
in India, I think it must rank as a distinct breed. Probably this is the
breed seen by Hasselquist in 1757 at Cairo, and said to have been imported
from India.]
RACE IX. JACOBIN. (ZOPF- OR PERRFICKENTAUBE; NONNAIN.)
Feathers of the neck forming a hood; wings and tail long; beak moderately
short.
[This pigeon can at once be recognised by its hood, almost enclosing the
head and meeting in front of the neck. The hood seems to be merely an
exaggeration of the crest of reversed feathers on the back of the head,
which is common to many sub-varieties, and which in the Latztaube (5/20.
Neumeister 'Taubenzucht' tab. 4. figure 1.) is in a nearly intermediate
state between a hood and a crest. The feathers of the hood are elongated.
Both the wings and tail are likewise much elongated; thus the folded wing
of the Jacobin, though a somewhat smaller bird, is fully 1 1/4 inch longer
than in the rock-pigeon. Taking the length of the body without the tail as
the standard of comparison, the folded wing, proportionally with the wings
of the rock-pigeon, is 2 1/4 inches too long, and the two wings, from tip
to tip, 5 1/4 inches too long. In disposition this bird is singularly
quiet, seldom flying or moving about, as Bechstein and Riedel have likewise
remarked in Germany. (5/21. Riedel 'Die Taubenzucht' 1824 s. 26. Bechstein
'Naturgeschichte Deutschlands' b. 4 s. 36 1795) The latter author also
notices the length of the wings and tail. The beak is nearly .2 of an inch
shorter in proportion to the size of the body than in the rock-pigeon; but
the internal gape of the mouth is considerably wider.]
GROUP IV.
The birds of this group may be characterised by their resemblance in all
important points of structure, especially in the beak, to the rock-pigeon.
The Trumpeter forms the only well-marked race. Of the numerous other sub-
races and varieties I shall specify only a few of the most distinct, which
I have myself seen and kept alive.
RACE X. TRUMPETER. (TROMMELTAUBE; PIGEON TAMBOUR, GLOUGLOU.)
A tuft of feathers at the base of the beak curling forward; feet much
feathered; voice very peculiar; size exceeding that of the rock-pigeon.
[This is a well-marked breed, with a peculiar voice, wholly unlike that of
any other pigeon. The coo is rapidly repeated, and is continued for several
minutes; hence their name of Trumpeters. They are also characterised by a
tuft of elongated feathers, which curls forward over the base of the beak,
and which is possessed by no other breed. Their feet are so heavily
feathered, that they almost appear like little wings. They are larger birds
than the rock-pigeon, but their beak is of very nearly the same
proportional size. Their feet are rather small. This breed was perfectly
characterised in Moore's time, in 1735. Mr. Brent says that two varieties
exist, which differ in size.]
RACE XI. SCARCELY DIFFERING IN STRUCTURE FROM THE WILD COLUMBA LIVIA.
SUB-RACE 11/I. LAUGHERS.
Size less than the Rock-pigeon; voice very peculiar.
[As this bird agrees in nearly all its proportions with the rock-pigeon,
though of smaller size, I should not have thought it worthy of mention, had
it not been for its peculiar voice--a character supposed seldom to vary
with birds. Although the voice of the Laugher is very different from that
of the Trumpeter, yet one of my Trumpeters used to utter a single note like
that of the Laugher. I have kept two varieties of Laughers, which differed
only in one variety being turn-crowned; the smooth-headed kind, for which I
am indebted to the kindness of Mr. Brent, besides its peculiar note, used
to coo in a singular and pleasing manner, which, independently, struck both
Mr. Brent and myself as resembling that of the turtle-dove. Both varieties
come from Arabia. This breed was known by Moore in 1735. A pigeon which
seems to say Yak-roo is mentioned in 1600 in the 'Ayeen Akbery' and is
probably the same breed. Sir W. Elliot has also sent me from Madras a
pigeon called Yahui, said to have come from Mecca, which does not differ in
appearance from the Laugher; it has "a deep melancholy voice, like Yahu,
often repeated." Yahu, yahu, means Oh God, oh God; and Sayzid Mohammed
Musari, in the treatise written about 100 years ago, says that these birds
"are not flown, because they repeat the name of the most high God." Mr.
Keith Abbott, however, informs me that the common pigeon is called Yahoo in
Persia.]
SUB-RACE 11/II. COMMON FRILL-BACK (DIE STRUPPTAUBE).
Beak rather longer than in the rock-pigeon; feathers reversed .
[This is a considerably larger bird than the rock-pigeon, and with the
beak, proportionally with the size of body, a little (viz. by .04 of an
inch) longer. The feathers, especially on the wing-coverts, have their
points curled upwards or back-wards.]
SUB-RACE 11/III. NUNS (PIGEONS COQUILLES).
[These elegant birds are smaller than the rock-pigeon. The beak is actually
1.7, and proportionally with the size of the body .1 of an inch shorter
than in the rock-pigeons, although of the same thickness. In young birds
the scutellae on the tarsi and toes are generally of a leaden-black colour;
and this is a remarkable character (though observed in a lesser degree in
some other breeds), as the colour of the legs in the adult state is subject
to very little variation in any breed. I have on two or three occasions
counted thirteen or fourteen feathers in the tail; this likewise occurs in
the barely distinct breed called Helmets. Nuns are symmetrically coloured,
with the head, primary wing-feathers, tail, and tail-coverts of the same
colour, namely, black or red, and with the rest of the body white. This
breed has retained the same character since Aldrovandi wrote in 1600. I
have received from Madras almost similarly coloured birds.]
SUB-RACE 11/IV. SPOTS (DIE BLASSTAUBEN; PIGEONS HEURTES).
[These birds are a very little larger than the rock-pigeon, with the beak a
trace smaller in all its dimensions, and with the feet decidedly smaller.
They are symmetrically coloured, with a spot on the forehead, with the tail
and tail-coverts of the same colour, the rest of the body being white. This
breed existed in 1676 (5/22. Willughby 'Ornithology' edited by Ray.); and
in 1735 Moore remarks that they breed truly, as is the case at the present
day.]
SUB-RACE 11/V. SWALLOWS.
[These birds, as measured from tip to tip of wing, or from the end of the
beak to the end of the tail, exceed in size the rock-pigeon; but their
bodies are much less bulky; their feet and legs are likewise smaller. The
beak is of about the same length, but rather slighter. Altogether their
general appearance is considerably different from that of the rock-pigeon.
Their heads and wings are of the same colour, the rest of the body being
white. Their flight is said to be peculiar. This seems to be a modern
breed, which, however, originated before the year 1795 in Germany, for it
is described by Bechstein.
Besides the several breeds now described, three or four other very distinct
kinds existed lately, or perhaps still exist, in Germany and France.
Firstly, the Karmeliten, or carme pigeon, which I have not seen; it is
described as of small size, with very short legs, and with an extremely
short beak. Secondly, the Finnikin, which is now extinct in England. It
had, according to Moore's (5/23. J.M. Eaton's edition (1858) of Moore page
98.) treatise, published in 1735, a tuft of feathers on the hinder part of
the head, which ran down its back not unlike a horse's mane. "When it is
salacious it rises over the hen and turns round three or four times,
flapping its wings, then reverses and turns as many times the other way."
The Turner, on the other hand, when it "plays to the female, turns only one
way." Whether these extraordinary statements may be trusted I know not; but
the inheritance of any habit may be believed, after what we have seen with
respect to the Ground-tumbler of India. MM. Boitard and Corbie describe a
pigeon (5/24. Pigeon pattu plongeur. 'Les Pigeons' etc. page 165.) which
has the singular habit of sailing for a considerable time through the air,
without flapping its wings, like a bird of prey. The confusion is
inextricable, from the time of Aldrovandi in 1600 to the present day, in
the accounts published of the Draijers, Smiters, Finnikins, Turners,
Claquers, etc., which are all remarkable from their manner of flight. Mr.
Brent informs me that he has seen one of these breeds in Germany with its
wing-feathers injured from having been so often struck together but he did
not see it flying. An old stuffed specimen of a Finnikin in the British
Museum presents no well-marked character. Thirdly, a singular pigeon with a
forked tail is mentioned in some treatises; and as Bechstein (5/25.
'Naturgeschichte Deutschlands' b. 4 s. 47.) briefly describes and figures
this bird, with a tail "having completely the structure of that of the
house-swallow," it must once have existed, for Bechstein was far too good a
naturalist to have confounded any distinct species with the domestic
pigeon. Lastly, an extraordinary pigeon imported from Belgium has lately
been exhibited at the Philoperisteron Society in London (5/26. Mr. W.B.
Tegetmeier 'Journal of Horticulture' January 20, 1863 page 58.), which
"conjoins the colour of an archangel with the head of an owl or barb, its
most striking peculiarity being the extraordinary length of the tail and
wing-feathers, the latter crossing beyond the tail, and giving to the bird
the appearance of a gigantic swift (Cypselus), or long-winged hawk." Mr.
Tegetmeier informs me that this bird weighed only 10 ounces, but in length
was 15 1/2 inches from tip to beak to end of tail, and 32 1/2 inches from
tip to tip of wing; now the wild rock-pigeon weighs 14 1/2 ounces, and
measures from tip to beak to end of tail 15 inches, and from tip to tip of
wing only 26 3/4 inches.]
I have now described all the domestic pigeons known to me, and have added a
few others on reliable authority. I have classed them under four Groups, in
order to mark their affinities and degrees of difference; but the third
group is artificial. The kinds examined by me form eleven races, which
include several sub-races; and even these latter present differences that
would certainly have been thought of specific value if observed in a state
of nature. The sub-races likewise include many strictly inherited
varieties; so that altogether there must exist, as previously remarked,
above 150 kinds which can be distinguished, though generally by characters
of extremely slight importance. Many of the genera of the Columbidae,
admitted by ornithologists, do not differ in any great degree from each
other; taking this into consideration, there can be no doubt that several
of the most strongly characterised domestic forms, if found wild, would
have been placed in at least five new genera. Thus a new genus would have
been formed for the reception of the improved English Pouter: a second
genus for Carriers and Runts; and this would have been a wide or
comprehensive genus, for it would have admitted common Spanish Runts
without any wattle, short-beaked Runts like the Tronfo, and the improved
English Carrier: a third genus would have been formed for the Barb: a
fourth for the Fantail: and lastly, a fifth for the short beaked, not-
wattled pigeons, such as Turbits and short-faced Tumblers. The remaining
domestic forms might have been included, in the same genus with the wild
rock-pigeon.
INDIVIDUAL VARIABILITY; VARIATIONS OF A REMARKABLE NATURE.
The differences which we have as yet considered are characteristic of
distinct breeds; but there are other differences, either confined to
individual birds, or often observed in certain breeds but not
characteristic of them. These individual differences are of importance, as
they might in most cases be secured and accumulated by man's power of
selection and thus an existing breed might be greatly modified or a new one
formed. Fanciers notice and select only those slight differences which are
externally visible; but the whole organisation is so tied together by
correlation of growth, that a change in one part is frequently accompanied
by other changes. For our purpose, modifications of all kinds are equally
important, and if affecting a part which does not commonly vary, are of
more importance than a modification in some conspicuous part. At the
present day any visible deviation of character in a well-established breed
is rejected as a blemish; but it by no means follows that at an early
period, before well-marked breeds had been formed, such deviations would
have been rejected; on the contrary, they would have been eagerly preserved
as presenting a novelty, and would then have been slowly augmented, as we
shall hereafter more clearly see, by the process of unconscious selection.
[I have made numerous measurements of the various parts of the body in the
several breeds, and have hardly ever found them quite the same in birds of
the same breed,--the differences being greater than we commonly meet with
in wild species within the same district. To begin with the primary
feathers of the wing and tail; but I must first mention, as some readers
may not be aware of the fact, that the number of the primary wing and tail-
feathers in wild birds is generally constant, and characterises, not only
whole genera, but even whole families. When the tail-feathers are unusually
numerous, as for instance in the swan, they are apt to be variable in
number; but this does not apply to the several species and genera of the
Columbidae, which never (as far as I can hear) have less than twelve or
more than sixteen tail-feathers; and these numbers characterise, with rare
exception, whole sub-families. (5/27. 'Coup-d'oeil sur L'Ordre des Pigeons'
par C.L. Bonaparte 'Comptes Rendus' 1854-55. Mr. Blyth in 'Annals of Nat.
Hist.' volume 19 1847 page 41, mentions, as a very singular fact, "that of
the two species of Ectopistes, which are nearly allied to each other, one
should have fourteen tail-feathers, while the other, the passenger pigeon
of North America, should possess but the usual number--twelve.") The wild
rock-pigeon has twelve tail-feathers. With Fantails, as we have seen, the
number varies from fourteen to forty-two. In two young birds in the same
nest I counted twenty-two and twenty-seven feathers. Pouters are very
liable to have additional tail-feathers, and I have seen on several
occasions fourteen or fifteen in my own birds. Mr. Bult had a specimen,
examined by Mr. Yarrell, with seventeen tail-feathers. I had a Nun with
thirteen, and another with fourteen tail-feathers; and in a Helmet, a breed
barely distinguishable from the Nun, I have counted fifteen, and have heard
of other such instances. On the other hand, Mr. Brent possessed a Dragon,
which during its whole life never had more than ten tail-feathers; and one
of my Dragons, descended from Mr. Brent's, had only eleven. I have seen a
Bald-head Tumbler with only ten; and Mr. Brent had an Air-Tumbler with the
same number, but another with fourteen tail-feathers. Two of these latter
Tumblers, bred by Mr. Brent, were remarkable,--one from having the two
central tail-feathers a little divergent, and the other from having the two
outer feathers longer by three-eighths of an inch than the others; so that
in both cases the tail exhibited a tendency, but in different ways, to
become forked. And this shows us how a swallow-tailed breed, like that
described by Bechstein, might have been formed by careful selection.
With respect to the primary wing-feathers, the number in the Columbidae, as
far as I can find out, is always nine or ten. In the rock-pigeon it is ten;
but I have seen no less than eight short-faced Tumblers with only nine
primaries, and the occurrence of this number has been noticed by fanciers,
owing to ten primaries of a white colour being one of the points in Short-
faced Bald-head-Tumblers. Mr. Brent, however, had an Air-Tumbler (not
short-faced) which had in both wings eleven primaries. Mr. Corker, the
eminent breeder of prize Carriers, assures me that some of his birds had
eleven primaries in both wings. I have seen eleven in one wing in two
Pouters. I have been assured by three fanciers that they have seen twelve
in Scanderoons; but as Neumeister asserts that in the allied Florence Runt
the middle flight-feather is often double, the number twelve may have been
caused by two of the ten primaries having each two shafts to a single
feather. The secondary wing-feathers are difficult to count, but the number
seems to vary from twelve to fifteen. The length of the wing and tail
relatively to the body, and of the wings to the tail, certainly varies; I
have especially noticed this in Jacobins. In Mr. Bult's magnificent
collection of Pouters, the wings and tail varied greatly in length; and
were sometimes so much elongated that the birds could hardly play upright.
In the relative length of the few first primaries I have observed only a
slight degree of variability. Mr. Brent informs me that he has observed the
shape of the first feather to vary very slightly. But the variation in
these latter points is extremely slight compared with the differences which
may be observed in the natural species of the Columbidae.
In the beak I have seen very considerable differences in birds of the same
breed, as in carefully bred Jacobins and Trumpeters. In Carriers there is
often a conspicuous difference in the degree of attenuation and curvature
of the beak. So it is indeed in many breeds: thus I had two strains of
black Barbs, which evidently differed in the curvature of the upper
mandible. In width of mouth I have found a great difference in two
Swallows. In Fantails of first-rate merit I have seen some birds with much
longer and thinner necks than in others. Other analogous facts could be
given. We have seen that the oil-gland is aborted in all Fantails (with the
exception of the sub-race from Java), and, I may add, so hereditary is this
tendency to abortion, that some, although not all, of the mongrels which I
reared from the Fantail and Pouter had no oil-gland; in one Swallow out of
many which I have examined, and in two Nuns, there was no oil-gland.
The number of the scutellae on the toes often varies in the same breed, and
sometimes even differs on the two feet of the same individual; the Shetland
rock-pigeon has fifteen on the middle, and six on the hinder toe; whereas I
have seen a Runt with sixteen on the middle and eight on the hind toe; and
a short-faced Tumbler with only twelve and five on these same toes. The
rock-pigeon has no sensible amount of skin between its toes; but I
possessed a Spot and a Nun with the skin extending for a space of a quarter
of an inch from the fork, between the two INNER toes. On the other hand, as
will hereafter be more fully shown, pigeons with feathered feet very
generally have the bases of their OUTER toes connected by skin. I had a red
Tumbler, which had a coo unlike that of its fellows, approaching in tone to
that of the Laugher: this bird had the habit, to a degree which I never saw
equalled in any other pigeon, of often walking with its wings raised and
arched in an elegant-manner. I need say nothing on the great variability,
in almost every breed, in size of body, in colour, in the feathering of the
feet, and in the feathers on the back of the head being reversed. But I may
mention a remarkable Tumbler (5/28. Described and figured in the 'Poultry
Chronicle' volume 3 1855 page 82.) exhibited at the Crystal Palace, which
had an irregular crest of feathers on its head, somewhat like the tuft on
the head of the Polish fowl. Mr. Bult reared a hen Jacobin with the
feathers on the thigh so long as to reach the ground, and a cock having,
but in a lesser degree, the same peculiarity: from these two birds he bred
others similarly characterised, which were exhibited at the Philoperisteron
Soc. I bred a mongrel pigeon which had fibrous feathers, and the wing and
tail-feathers so short and imperfect that the bird could not fly even a
foot in height.]
There are many singular and inherited peculiarities in the plumage of
pigeons: thus Almond-Tumblers do not acquire their perfect mottled feathers
until they have moulted three or four times: the Kite Tumbler is at first
brindled black and red with a barred appearance, but when "it throws its
nest feathers it becomes almost black, generally with a bluish tail, and a
reddish colour on the inner webs of the primary wing-feathers." (5/29. 'The
Pigeon Book' by Mr. B.P. Brent 1859 page 41.) Neumeister describes a breed
of a black colour with white bars on the wing and a white crescent-shaped
mark on the breast; these marks are generally rusty-red before the first
moult, but after the third or fourth moult they undergo a change; the wing-
feathers and the crown of the head likewise then become white or grey.
(5/30. 'Die staarhalsige Taube. Das Ganze, etc.' s. 21 tab. 1. figure 4.)
It is an important fact, and I believe there is hardly an exception to the
rule, that the especial characters for which each breed is valued are
eminently variable: thus, in the Fantail, the number and direction of the
tail-feathers, the carriage of the body, and the degree of trembling are
all highly variable points; in Pouters, the degree to which they pout, and
the shape of their inflated crops; in the Carrier, the length, narrowness,
and curvature of the beak, and the amount of wattle; in Short-faced
Tumblers, the shortness of the beak, the prominence of the forehead, and
general carriage (5/31. 'A Treatise on the Almond-Tumbler' by J.M. Eaton
1852 page 8 et passim.), and in the Almond-Tumbler the colour of the
plumage; in common Tumblers, the manner of tumbling; in the Barb, the
breadth and shortness of the beak and the amount of eye-wattle; in Runts,
the size of body; in Turbits the frill; and lastly in Trumpeters, the
cooing, as well as the size of the tuft of feathers over the nostrils.
These, which are the distinctive and selected characters of the several
breeds, are all eminently variable.
There is another interesting fact with respect to the characters of the
several breeds, namely, that they are often most strongly displayed in the
male bird. In Carriers, when the males and females are exhibited in
separate pens, the wattle is plainly seen to be much more developed in the
males, though I have seen a hen Carrier belonging to Mr. Haynes heavily
wattled. Mr. Tegetmeier informs me that, in twenty Barbs in Mr. P.H.
Jones's possession, the males had generally the largest eye-wattles; Mr.
Esquilant also believes in this rule, but Mr. H. Weir, a first-rate judge,
entertains some doubt on the subject. Male Pouters distend their crops to a
much greater size than do the females; I have, however, seen a hen in the
possession of Mr. Evans which pouted excellently; but this is an unusual
circumstance. Mr. Harrison Weir, a successful breeder of prize Fantails,
informs me that his male birds often have a greater number of tail-feathers
than the females. Mr. Eaton asserts (5/32. 'A Treatise, etc.' page 10.)
that if a cock and hen Tumbler were of equal merit, the hen would be worth
double the money; and as pigeons always pair, so that an equal number of
both sexes is necessary for reproduction, this seems to show that high
merit is rarer in the female than in the male. In the development of the
frill in Turbits, of the hood in Jacobins, of the tuft in Trumpeters, of
tumbling in Tumblers, there is no difference between the males and females.
I may here add a rather different case, namely, the existence in France
(5/33. Boitard and Corbie 'Les Pigeons' etc. 1824 page 173.) of a wine-
coloured variety of the Pouter, in which the male is generally chequered
with black, whilst the female is never so chequered. Dr. Chapuis also
remarks (5/34. 'Le Pigeon Voyageur Belge' 1865 page 87. I have given in my
'Descent of Man' 6th edition page 466 some curious cases, on the authority
of Mr. Tegetmeier, of silver-coloured (i.e. very pale blue) birds being
generally females, and of the ease with which a race thus characterised
could be produced. Bonizzi (see 'Variazioni dei Columbi domestici' Padova
1873) states that certain coloured spots are often different in the two
sexes, and the certain tints are commoner in females than in male pigeons.)
that in certain light-coloured pigeons the males have their feathers
striated with black, and these striae increase in size at each moult, so
that the male ultimately becomes spotted with black. With Carriers, the
wattle, both on the beak and round the eyes, and with Barbs that round the
eyes, goes on increasing with age. This augmentation of character with
advancing age, and more especially the difference between the males and
females in the above-mentioned several respects, are remarkable facts, for
there is no sensible difference at any age between the two sexes in the
aboriginal rock-pigeon; and not often any strongly marked difference
throughout the family of the Columbidae. (5/35. Prof. A. Newton 'Proc.
Zoolog. Soc.' 1865 page 716 remarks that he knows no species which present
any remarkable sexual distinction; but Mr. Wallace informs me, that in the
sub-family of the Treronidae the sexes often differ considerably in colour.
See also on sexual differences in the Columbidae, Gould 'Handbook to the
Birds of Australia' volume 2 pages 109-149.)
OSTEOLOGICAL CHARACTERS.
In the skeletons of the various breeds there is much variability; and
though certain differences occur frequently, and others rarely, in certain
breeds, yet none can be said to be absolutely characteristic of any breed.
Considering that strongly-marked domestic races have been formed chiefly by
man's selection, we ought not to expect to find great and constant
differences in the skeleton; for fanciers neither see, nor do they care
for, modifications of structure in the internal framework. Nor ought we to
expect changes in the skeletons from changed habits of life; as every
facility is given to the most distinct breeds to follow the same habits,
and the much modified races are never allowed to wander abroad and procure
their own food in various ways. Moreover, I find, on comparing the
skeletons of Columba livia, oenas, palumbus, and turtur, which are ranked
by all systematists in two or three distinct though allied genera, that the
differences are extremely slight, certainly less than between the skeletons
of some of the most distinct domestic breeds. How far the skeleton of the
wild rock-pigeon is constant I have had no means of judging, as I have
examined only two.
(FIGURE 24. SKULLS OF PIGEONS viewed laterally, of natural size. A. Wild
Rock-pigeon, Columba livia. B. Short-faced Tumbler. C. English Carrier. D.
Bagadotten Carrier.)
[SKULL.
The individual bones, especially those at the base, do not differ in shape.
But the whole skull, in its proportions, outline, and relative direction of
the bones, differs greatly in some of the breeds, as may be seen by
comparing the figures of (A) the wild rock-pigeon, (B) the Short-faced
Tumbler, (C) the English Carrier, and (D) the Bagadotten Carrier (of
Neumeister), all drawn of the natural size and viewed laterally. In the
Carrier, besides the elongation of the bones of the face, the space between
the orbits is proportionally a little narrower than in the rock-pigeon. In
the Bagadotten the upper mandible is remarkably arched, and the
premaxillary bones are proportionally broader. In the Short-faced Tumbler
the skull is more globular: all the bones of the face are much shortened,
and the front of the skull and descending nasal bones are almost
perpendicular: the maxillo-jugal arch and premaxillary bones form an almost
straight line; the space between the prominent edges of the eye-orbits is
depressed. In the Barb the premaxillary bones are much shortened, and their
anterior portion is thicker than in the rock-pigeon, as is the lower part
of the nasal bone. In two Nuns the ascending branches of the
premaxillaries, near their tips, were somewhat attenuated, and in these
birds, as well as in some others, for instance in the Spot, the occipital
crest over the foramen was considerably more prominent than in the rock-
pigeon.
(FIGURE 25. LOWER JAWS, seen from above, of natural size. A. Rock-pigeon.
B. Runt. C. Barb.
FIGURE 26. SKULL OF RUNT, seen from above, of natural size, showing the
reflexed margin of the distal portion of the lower jaw.
FIGURE 27. LATERAL VIEW OF JAWS, of natural size. A. Rock-pigeon. B.
Shortfaced Tumbler. C. Bagadotten Carrier.)
In the lower jaw, the articular surface is proportionably smaller in many
breeds than in the rock-pigeon; and the vertical diameter, more especially
of the outer part of the articular surface, is considerably shorter. May
not this be accounted for by the lessened use of the jaws, owing to
nutritious food having been given during a long period to all highly
improved pigeons? In Runts, Carriers, and Barbs (and in a lesser degree in
several breeds), the whole side of the jaw near the articular end is bent
inwards in a highly remarkable manner; and the superior margin of the
ramus, beyond the middle, is reflexed in an equally remarkable manner, as
may be seen in figure 25, in comparison with the jaw of the rock-pigeon.
This reflection of the upper margin of the lower jaw is plainly connected
with the singularly wide gape of the mouth, as has been described in Runts,
Carriers, and Barbs. The reflection is well shown in figure 26 of the head
of a Runt seen from above; here a wide open space may be observed on each
side, between the edges of the lower jaw and of the premaxillary bones. In
the rock-pigeon, and in several domestic breeds, the edges of the lower jaw
on each side come close up to the premaxillary bones, so that no open space
is left. The degree of downward curvature of the distal half of the lower
jaw also differs to an extraordinary degree in some breeds, as may be seen
in the drawings (figure 27 A) of the rock-pigeon, (B) of the Short-faced
Tumbler, and (C) of the Bagadotten Carrier of Neumeister. In some Runts the
symphysis of the lower jaw is remarkably solid. No one would readily have
believed that jaws differing in the several above-specified points so
greatly could have belonged to the same species.
VERTEBRAE.
All the breeds have twelve cervical vertebrae. (5/36. I am not sure that I
have designated the different kinds of vertebra correctly: but I observe
that different anatomists follow in this respect different rules, and, as I
use the same terms in the comparison of all the skeletons, this, I hope,
will not signify.) But in a Bussorah Carrier from India the twelfth
vertebra carried a small rib, a quarter of an inch in length, with a
perfect double articulation.
The DORSAL VERTEBRAE are always eight. In the rock-pigeon all eight bear
ribs; the eighth rib being very thin, and the seventh having no process. In
Pouters all the ribs are extremely broad, eight bear ribs; the eighth rib
being very thin and the seventh having no process. In Pouters all the ribs
are extremely broad, and, in three out of four skeletons examined by me,
the eighth rib was twice or even thrice as broad as in the rock-pigeon; and
the seventh pair had distinct processes. In many breeds there are only
seven ribs, as in seven out of eight skeletons of various Tumblers, and in
several skeletons of Fantails, Turbits and Nuns.
In all these breeds the seventh pair was very small, and was destitute of
processes, in which respect it differed from the same rib in the rock-
pigeon. In one Tumbler, and in the Bussorah Carrier, even the sixth pair
had no process. The hypapophysis of the second dorsal vertebra varies much
in development; being sometimes (as in several, but not all Tumblers)
nearly as prominent as that of the third dorsal vertebra; and the two
hypapophyses together tend to form an ossified arch. The development of the
arch, formed by the hypapophyses of the third and fourth dorsal vertebrae,
also varies considerably, as does the size of the hypapophysis of the fifth
vertebra.
The rock-pigeon has twelve sacral vertebrae; but these vary in number,
relative size, and distinctness, in the different breeds. In Pouters, with
their elongated bodies, there are thirteen or even fourteen, and, as we
shall immediately see, an additional number of caudal vertebrae. In Runts
and Carriers there is generally the proper number, namely twelve; but in
one Runt, and in the Bussorah Carrier, there were only eleven. In Tumblers
there are either eleven, or twelve, or thirteen sacral vertebrae.
The CAUDAL VERTEBRAE are seven in number in the rock-pigeon. In Fantails,
which have their tails so largely developed, there are eight or nine, and
apparently in one case ten, and they are a little longer than in the rock-
pigeon, and their shape varies considerably. Pouters, also, have eight or
nine caudal vertebrae. I have seen eight in a Nun and Jacobin. Tumblers,
though such small birds, always have the normal number seven; as have
Carriers, with one exception, in which there were only six.
The following table will serve as a summary, and will show the most
remarkable deviations in the number of the vertebra and ribs which I have
observed:--
TABLE 4. NUMBER OF VERTEBRAE AND RIBS IN:
1. THE ROCK PIGEON.
Cervical Vertebrae: 12.
Dorsal Vertebrae: 8.
Dorsal Ribs: 8.
The 6th pair with processes, the 7th pair without a process.
Sacral Vertebrae: 12.
Caudal Vertebrae: 7.
Total: 39.
2. POUTER, FROM MR. BULT.
Cervical Vertebrae: 12.
Dorsal Vertebrae: 8.
Dorsal Ribs: 8.
The 6th and 7th pair with processes.
Sacral Vertebrae: 14.
Caudal Vertebrae: 8 or 9.
Total: 42 or 43.
3. TUMBLER, DUTCH ROLLER.
Cervical Vertebrae: 12.
Dorsal Vertebrae: 8.
Dorsal Ribs: 7.
The 6th and 7th pair without processes.
Sacral Vertebrae: 11.
Caudal Vertebrae: 7.
Total: 38.
4. BUSSORAH CARRIER.
Cervical Vertebrae: 12.
The twelfth bore a small rib.
Dorsal Vertebrae: 8.
Dorsal Ribs: 7.
The 6th and 7th pair without processes.
Sacral Vertebrae: 11.
Caudal Vertebrae: 7.
Total: 38.
The PELVIS differs very little in any breed. The anterior margin of the
ilium, however, is sometimes a little more equally rounded on both sides
than in the rock-pigeon. The ischium is also frequently rather more
elongated. The obturator-notch is sometimes, as in many Tumblers, less
developed than in the rock-pigeon. The ridges on the ilium are very
prominent in most Runts.
(FIGURE 28. SCAPULAE, of natural size. A. Rock-pigeon. B. Short-faced
Tumbler.)
In the bones of the extremities I could detect no difference, except in
their proportional lengths; for instance, the metatarsus in a Pouter was
1.65 inch, and in a Short-faced Tumbler only .95 in length; and this is a
greater difference than would naturally follow from their differently-sized
bodies; but long legs in the Pouter, and small feet in the Tumbler, are
selected points. In some Pouters the SCAPULA is rather straighter, and in
some Tumblers it is straighter, with the apex less elongated, than in the
rock-pigeon: in figure 28, the scapula of the rock-pigeon (A), and of a
short-faced Tumbler (B), are given. The processes at the summit of the
CORACOID, which receive the extremities of the furculum, form a more
perfect cavity in some Tumblers than in the rock-pigeon: in Pouters these
processes are larger and differently shaped, and the exterior angle of the
extremity of the coracoid, which is articulated to the sternum, is squarer.
(FIGURE 29. FURCULA, of natural size. A. Short-faced Tumbler. B and C
Fantail. D. Pouter.)
The two arms of the FURCULUM in Pouters diverge less, proportionally to
their length, than in the rock-pigeon; and the symphysis is more solid and
pointed. In Fantails the degree of divergence of the two arms varies in a
remarkable manner. In figure 29, B and C represent the furcula of two
Fantails; and it will be seen that the divergence in B is rather less even
than in the furculum of the short-faced, small-sized Tumbler (A), whereas
the divergence in C equals that in a rock-pigeon, or in the Pouter (D),
though the latter is a much larger bird. The extremities of the furculum,
where articulated to the coracoids, vary considerably in outline.
In the STERNUM the differences in form are slight, except in the size and
outline of the perforations, which, both in the larger and lesser sized
breeds, are sometimes small. These perforations, also, are sometimes either
nearly circular, or elongated as is often the case with Carriers. The
posterior perforations occasionally are not complete, being left open
posteriorly. The marginal apophyses forming the anterior perforations vary
greatly in development. The degree of convexity of the posterior part of
the sternum differs much, being sometimes almost perfectly flat. The
manubrium is rather more prominent in some individuals than in others, and
the pore immediately under it varies greatly in size.]
CORRELATION OF GROWTH.
By this term I mean that the whole organisation is so connected, that when
one part varies, other parts vary; but which of two correlated variations
ought to be looked at as the cause and which as the effect, or whether both
result from some common cause, we can seldom or never tell. The point of
interest for us is that, when fanciers, by the continued selection of
slight variations, have largely modified one part, they often
unintentionally produce other modifications. For instance, the beak is
readily acted on by selection, and, with its increased or diminished
length, the tongue increases or diminishes, but not in due proportion; for,
in a Barb and Short-faced Tumbler, both of which have very short beaks, the
tongue, taking the rock-pigeon as the standard of comparison, was
proportionally not shortened enough, whilst in two Carriers and in a Runt
the tongue, proportionally with the beak, was not lengthened enough, thus,
in a first-rate English Carrier, in which the beak from the tip to the
feathered base was exactly thrice as long as in a first-rate Short-faced
Tumbler, the tongue was only a little more than twice as long. But the
tongue varies in length independently of the beak: thus in a Carrier with a
beak 1.2 inch in length, the tongue was .67 in length: whilst in a Runt
which equalled the Carrier in length of body and in stretch of wings from
tip to tip, the beak was .92 whilst the tongue was .73 of an inch in
length, so that the tongue was actually longer than in the carrier with its
long beak. The tongue of the Runt was also very broad at the root. Of two
Runts, one had its beak longer by .23 of an inch, whilst its tongue was
shorter by .14 than in the other.
With the increased or diminished length of the beak the length of the slit
forming the external orifice of the nostrils varies, but not in due
proportion, for, taking the rock-pigeon as the standard, the orifice in a
Short-faced Tumbler was not shortened in due proportion with its very short
beak. On the other hand (and this could not have been anticipated), the
orifice in three English Carriers, in the Bagadotten Carrier, and in a Runt
(pigeon cygne), was longer by above the tenth of an inch than would follow
from the length of the beak proportionally with that of the rock-pigeon. In
one Carrier the orifice of the nostrils was thrice as long as in the rock-
pigeon, though in body and length of beak this bird was not nearly double
the size of the rock-pigeon. This greatly increased length of the orifice
of the nostrils seems to stand partly in correlation with the enlargement
of the wattled skin on the upper mandible and over the nostrils; and this
is a character which is selected by fanciers. So again, the broad, naked,
and wattled skin round the eyes of Carriers and Barbs is a selected
character; and in obvious correlation with this, the eyelids, measured
longitudinally, are proportionally more than double the length of those of
the rock-pigeon.
The great difference (see figure 27) in the curvature of the lower jaw in
the rock-pigeon, the Tumbler, and Bagadotten Carrier, stands in obvious
relation to the curvature of the upper jaw, and more especially to the
angle formed by the maxillo-jugal arch with the premaxillary bones. But in
Carriers, Runts, and Barbs the singular reflexion of the upper margin of
the middle part of the lower jaw (see figure 25) is not strictly correlated
with the width or divergence (as may be clearly seen in figure 26) of the
premaxillary bones, but with the breadth of the horny and soft parts of the
upper mandible, which are always overlapped by the edges of the lower
mandible.
In Pouters, the elongation of the body is a selected character, and the
ribs, as we have seen, have generally become very broad, with the seventh
pair furnished with processes; the sacral and caudal vertebrae have been
augmented in number; the sternum has likewise increased in length (but not
in the depth of the crest) by .4 of an inch more than would follow from the
greater bulk of the body in comparison with that of the rock-pigeon. In
Fantails, the length and number of the caudal vertebrae have increased.
Hence, during the gradual progress of variation and selection, the internal
bony framework and the external shape of the body have been, to a certain
extent, modified in a correlated manner.
Although the wings and tail often vary in length independently of each
other, it is scarcely possible to doubt that they generally tend to become
elongated or shortened in correlation. This is well seen in Jacobins, and
still more plainly in Runts, some varieties of which have their wings and
tail of great length, whilst others have both very short. With Jacobins,
the remarkable length of the tail and wing-feathers is not a character
which is intentionally selected by fanciers; but fanciers have been trying
for centuries, at least since the year 1600, to increase the length of the
reversed feathers on the neck, so that the hood may more completely enclose
the head; and it may be suspected that the increased length of the wing and
tail-feathers stand in correlation with the increased length of the neck-
feathers. Short-faced Tumblers have short wings in nearly due proportion
with the reduced size of their bodies; but it is remarkable, seeing that
the number of the primary wing-feathers is a constant character in most
birds, that these Tumblers generally have only nine instead of ten
primaries. I have myself observed this in eight birds; and the Original
Columbarian Society (5/37. J.M. Eaton 'Treatise' edition 1858 page 78.)
reduced the standard for Bald-head Tumblers from ten to nine white flight-
feathers, thinking it unfair that a bird which had only nine feathers
should be disqualified for a prize because it had not ten WHITE flight-
feathers. On the other hand, in Carriers and Runts, which have large bodies
and long wings, eleven primary feathers have occasionally been observed.
Mr. Tegetmeier has informed me of a curious and inexplicable case of
correlation, namely, that young pigeons of all breeds which when mature
become white, yellow, silver (i.e., extremely pale blue), or dun-coloured,
are born almost naked; whereas pigeons of other colours are born well-
clothed with down. Mr. Esquilant, however, has observed that young dun
Carriers are not so bare as young dun Barbs and Tumblers. Mr. Tegetmeier
has seen two young birds in the same nest, produced from differently
coloured parents, which differed greatly in the degree to which they were
at first clothed with down.
I have observed another case of correlation which at first sight appears
quite inexplicable, but on which, as we shall see in a future chapter, some
light can be thrown by the law of homologous parts varying in the same
manner. The case is, that, when the feet are much feathered, the roots of
the feathers are connected by a web of skin, and apparently in correlation
with this the two outer toes become connected for a considerable space by
skin. I have observed this in very many specimens of Pouters, Trumpeters,
Swallows, Roller-tumblers (likewise observed in this breed by Mr. Brent),
and in a lesser degree in other feather-footed pigeons.
The feet of the smaller and larger breeds are of course much smaller or
larger than those of the rock-pigeon; but the scutellae or scales covering
the toes and tarsi have not only decreased or increased in size, but
likewise in number. To give a single instance, I have counted eight
scutellae on the hind toe of a Runt, and only five on that of a Short-faced
Tumbler. With birds in a state of nature the number of the scutellae on the
feet is usually a constant character. The length of the feet and the length
of the beak apparently stand in correlation; but as disuse apparently has
affected the size of the feet, this case may come under the following
discussion.
ON THE EFFECTS OF DISUSE.
In the following discussion on the relative proportions of the feet,
sternum, furculum, scapulae, and wings, I may premise, in order to give
some confidence to the reader, that all my measurements were made in the
same manner, and that they were made without the least intention of
applying them to the following purpose.
[TABLE 5.I.
PIGEONS WITH THEIR BEAKS GENERALLY SHORTER THAN THAT OF THE ROCK-PIGEON,
PROPORTIONALLY TO THE SIZE OF THEIR BODIES.
Column 1. Name of Breed.
Column 2. Actual length of Feet (inches).
Column 3. Difference between actual and calculated length of feet, in
proportion to length of feet and size of body in the Rock-pigeon.
Column 3a. Too short by (inches).
Column 3b. Too long by (inches).
1. 2. 3a. 3b.
Wild rock-pigeon (mean measurement). 2.02
Short-faced Tumbler, bald-head. 1.57 0.11 ..
Short-faced Tumbler, almond. 1.60 0.16 ..
Tumbler, red magpie. 1.75 0.19 ..
Tumbler, red common (by standard to end of tail). 1.85 0.07 ..
Tumbler, common bald-head. 1.85 0.18 ..
Tumbler, roller. 1.80 0.06 ..
Turbit. 1.75 0.17 ..
Turbit. 1.80 0.01 ..
Turbit. 1.84 0.15 ..
Jacobin. 1.90 0.02 ..
Trumpeter, white. 2.02 0.06 ..
Trumpeter, mottled. 1.95 0.18 ..
Fantail (by standard to end of tail). 1.85 0.15 ..
Fantail (by standard to end of tail). 1.95 0.15 ..
Fantail crested var. Ditto. 1.95 0.0 0.0
Indian Frill-back Ditto. 1.8O 0.19 ..
English Frill-back. 2.10 0.03 ..
Nun. 1.82 0.02 ..
Laugher. 1.65 0.16 ..
Barb. 2.00 0.03 ..
Barb. 2.00 ..
0.03
Spot. 1.90 0.02 ..
Spot. 1.90 0.07 ..
Swallow, red. 1.85 0.18 ..
Swallow, blue. 2.00 ..
0.03
Pouter. 2.42 ..
0.11
Pouter, German. 2.30 ..
0.09
Bussorah Carrier. 2.17 ..
0.09
Number of specimens. 28 22 5
I measured most of the birds which came into my possession, from the
feathered BASE of the beak (the length of beak itself being so variable) to
the end of the tail, and to the oil-gland, but unfortunately (except in a
few cases) not to the root of the tail; I measured each bird from the
extreme tip to tip of wing; and the length of the terminal folded part of
the wing, from the extremity of the primaries to the joint of the radius. I
measured the feet without the claws, from the end of the middle toe to the
end of the hind toe; and the tarsus and middle toe together. I have taken
in every case the mean measurement of two wild rock-pigeons from the
Shetland Islands, as the standard of comparison. The following table shows
the actual length of the feet in each bird; and the difference between the
length which the feet ought to have had according to the size of body of
each, in comparison with the size of body and length of feet of the rock-
pigeon, calculated (with a few specified exceptions) by the standard of the
length of the body from the base of the beak to the oil-gland. I have
preferred this standard, owing to the variability of the length of tail.
But I have made similar calculations, taking as the standard the length
from tip to tip of wing, and likewise in most cases from the base of the
beak to the end of the tail; and the result has always been closely
similar. To give an example: the first bird in the table, being a Short-
faced Tumbler, is much smaller than the rock-pigeon, and would naturally
have shorter feet; but it is found on calculation to have feet too short by
.11 of an inch, in comparison with the feet of the rock-pigeon, relatively
to the size of the body in these two birds, as measured from the base of
beak to the oil-gland. So again, when this same Tumbler and the rock-pigeon
were compared by the length of their wings, or by the extreme length of
their bodies, the feet of the Tumbler were likewise found to be too short
in very nearly the same proportion. I am well aware that the measurements
pretend to greater accuracy than is possible, but it was less trouble to
write down the actual measurements given by the compasses in each case than
an approximation.
TABLE 5.II.
PIGEONS WITH THEIR BEAKS LONGER THAN THAT OF THE ROCK-PIGEON,
PROPORTIONALLY TO THE SIZE OF THEIR BODIES.
Column 1. Name of Breed.
Column 2. Actual length of Feet (inches).
Column 3. Difference between actual and calculated length of feet, in
proportion to length of feet and size of body in the Rock-pigeon.
Column 3a. Too short by (inches).
Column 3b. Too long by (inches).
1. 2. 3a. 3b.
Wild rock-pigeon (mean measurement). 2.02
Carrier. 2.60 ..
0.31
Carrier. 2.60 ..
0.25
Carrier. 2.40 ..
0.21
Carrier, Dragon. 2.25 ..
0.06
Bagadotten Carrier. 2.80 ..
0.56
Scanderoon, white. 2.80 ..
0.37
Scanderoon, Pigeon cygne. 2.85 ..
0.29
Runt. 2.75 ..
0.27
Number of specimens. 8 .. 8
In these two tables (Tables 5.I.and 5.II.) we see in the first column the
actual length of the feet in thirty-six birds belonging to various breeds,
and in the two other columns we see by how much the feet are too short or
too long, according to the size of bird, in comparison with the rock-
pigeon. In the first table twenty-two specimens have their feet too short,
on an average by a little above the tenth of an inch (viz. .107); and five
specimens have their feet on an average a very little too long, namely, by
.07 of an inch. But some of these latter cases can be explained; for
instance, with Pouters the legs and feet are selected for length, and thus
any natural tendency to a diminution in the length of the feet will have
been counteracted. In the Swallow and Barb, when the calculation was made
on any standard of comparison besides the one used (viz. length of body
from base of beak to oil-gland), the feet were found to be too small.
In the second table we have eight birds, with their beaks much longer than
in the rock-pigeon, both actually and proportionally with the size of body,
and their feet are in an equally marked manner longer, namely, in
proportion, on an average by .29 of an inch. I should here state that in
Table 5.I. there are a few partial exceptions to the beak being
proportionally shorter than in the rock-pigeon: thus the beak of the
English Frill-back is just perceptibly longer, and that of the Bussorah
Carrier of the same length or slightly longer, than in the rock-pigeon. The
beaks of Spots, Swallows, and Laughers are only a very little shorter, or
of the same proportional length, but slenderer. Nevertheless, these two
tables, taken conjointly, indicate pretty plainly some kind of correlation
between the length of the beak and the size of the feet. Breeders of cattle
and horses believe that there is an analogous connection between the length
of the limbs and head; they assert that a race-horse with the head of a
dray-horse, or a grey-hound with the head of a bulldog, would be a
monstrous production. As fancy pigeons are generally kept in small
aviaries, and are abundantly supplied with food, they must walk about much
less than the wild rock-pigeon; and it may be admitted as highly probable
that the reduction in the size of the feet in the twenty-two birds in the
first table has been caused by disuse (5/38. In an analogous, but converse,
manner, certain natural groups of the Columbidae, from being more
terrestrial in their habits than other allied groups, have larger feet. See
Prince Bonaparte 'Coup d'oeil sur l'Ordre des Pigeons.'), and that this
reduction has acted by correlation on the beaks of the great majority of
the birds in Table 5.I. When, on the other hand, the beak has been much
elongated by the continued selection of successive slight increments of
length, the feet by correlation have likewise become much elongated in
comparison with those of the wild rock-pigeon, notwithstanding their
lessened use.
As I had taken measures from the end of the middle toe to the heel of the
tarsus in the rock-pigeon and in the above thirty-six birds, I have made
calculations analogous with those above given, and the result is the same--
namely, that in the short-beaked breeds, with equally few exceptions as in
the former case, the middle toe conjointly with the tarsus has decreased in
length; whereas in the long-beaked breeds it has increased in length,
though not quite so uniformly as in the former case, for the leg, in some
varieties of the Runt varies much in length.
LENGTH OF STERNUM.
As fancy pigeons are generally confined in aviaries of moderate size, and
as even when not confined they do not search for their own food, they must
during many generations have used their wings incomparably less than the
wild rock-pigeon. Hence it seemed to me probable that all the parts of the
skeleton subservient to flight would be found to be reduced in size. With
respect to the sternum, I have carefully measured its extreme length in
twelve birds of different breeds, and in two wild rock-pigeons from the
Shetland Islands. For the proportional comparison I have tried three
standards of measurement, with all twelve birds namely, the length from the
base of the beak to the oil-gland, to the end of the tail, and from the
extreme tip to tip of wings. The result has been in each case nearly the
same, the sternum being invariably found to be shorter than in the wild
rock-pigeon. I will give only a single table, as calculated by the standard
from the base of the beak to the oil-gland; for the result in this case is
nearly the mean between the results obtained by the two other standards.
TABLE 5.III.
LENGTH OF STERNUM.
Column 1. Name of Breed.
Column 2. Actual Length in Inches.
Column 3. Too short by (inches).
1. 2. 3.
Wild Rock-pigeon. 2.55
Pied Scanderoon. 2.80 0.60
Bagadotten Carrier. 2.80 0.17
Dragon. 2.45 0.41
Carrier. 2.75 0.35
Short-faced Tumbler. 2.05 0.28
Barb. 2.35 0.34
Nun. 2.27 0.15
German Pouter. 2.36 0.54
Jacobin. 2.33 0.22
English Frill-back. 2.40 0.43
Swallow. 2.45 0.17
This table (Table 5.III.) shows that in these twelve breeds the sternum is
of an average one-third of an inch (exactly .332) shorter than in the rock-
pigeon, proportionally with the size of their bodies; so that the sternum
has been reduced by between one-seventh and one-eighth of its entire
length; and this is a considerable reduction.
I have also measured in twenty-one birds, including the above dozen, the
prominence of the crest of the sternum relatively to its length,
independently of the size of the body. In two of the twenty-one birds the
crest was prominent in the same relative degree as in the rock-pigeon; in
seven it was more prominent; but in five out of these seven, namely, in a
Fantail, two Scanderoons, and two English Carriers, this greater prominence
may to a certain extent be explained, as a prominent breast is admired and
selected by fanciers; in the remaining twelve birds the prominence was
less. Hence it follows that the crest exhibits a slight, though uncertain,
tendency to be reduced in prominence in a greater degree than does the
length of the sternum relatively to the size of body, in comparison with
the rock-pigeon.
I have measured the length of the scapula in nine different large and
small-sized breeds, and in all the scapula is proportionally shorter
(taking the same standard as before) than in the wild rock-pigeon. The
reduction in length on an average is very nearly one-fifth of an inch, or
about one-ninth of the length of the scapula in the rock-pigeon.
The arms of the furcula in all the specimens which I compared, diverged
less, proportionally with the size of body, than in the rock-pigeon; and
the whole furculum was proportionally shorter. Thus in a Runt, which
measured from tip to tip of wings 38 1/2 inches, the furculum was only a
very little longer (with the arms hardly more divergent) than in a rock-
pigeon which measured from tip to tip 26 1/2 inches. In a Barb, which in
all its measurements was a little larger than the same rock-pigeon, the
furculum was a quarter of an inch shorter. In a Pouter, the furculum had
not been lengthened proportionally with the increased length of the body.
In a Short-faced Tumbler, which measured from tip to tip of wings 24
inches, therefore only 2 1/2 inches less than the rock-pigeon, the furculum
was barely two-thirds of the length of that of the rock-pigeon.]
We thus clearly see that the sternum, scapula, and furculum are all reduced
in proportional length; but when we turn to the wings we find what at first
appears a wholly different and unexpected result. I may here remark that I
have not picked out specimens, but have used every measurement made by me.
Taking the length from the base of beak to the end of the tail as the
standard of comparison, I find that, out of thirty-five birds of various
breeds, twenty-five have wings of greater, and ten have them of less
proportional length, than in the rock-pigeon. But from the frequently
correlated length of the tail and wing-feathers, it is better to take as
the standard of comparison the length from the base of the beak to the oil-
gland; and by this standard, out of twenty-six of the same birds which had
been thus measured, twenty-one had wings too long, and only five had them
too short. In the twenty-one birds the wings exceeded in length those of
the rock-pigeon, on an average, by 1 1/3 inch; whilst in the five birds
they were less in length by only .8 of an inch. As I was much surprised
that the wings of closely confined birds should thus so frequently have
been increased in length, it occurred to me that it might be solely due to
the greater length of the wing-feathers; for this certainly is the case
with the Jacobin, which has wings of unusual length. As in almost every
case I had measured the folded wings, I subtracted the length of this
terminal part from that of the expanded wings, and thus I obtained, with a
moderate degree of accuracy, the length of the wings from the ends of the
two radii, answering from wrist to wrist in our arms. The wings, thus
measured in the same twenty-five birds, now gave a widely different result;
for they were proportionally with those of the rock-pigeon too short in
seventeen birds, and in only eight too long. Of these eight birds, five
were long-beaked (5/39. It perhaps deserves notice that besides these five
birds two of the eight were Barbs, which, as I have shown, must be classed
in the same group with the long-beaked Carriers and Runts. Barbs may
properly be called short-beaked Carriers. It would, therefore, appear as
if, during the reduction of their beaks, their wings had retained a little
of that excess of length which is characteristic of their nearest relations
and progenitors.), and this fact perhaps indicates that there is some
correlation of the length of the beak with the length of the bones of the
wings, in the same manner as with that of the feet and tarsi. The
shortening of the humerus and radius in the seventeen birds may probably be
attributed to disuse, as in the case of the scapula and furculum to which
the wing-bones are attached;--the lengthening of the wing-feathers, and
consequently the expansion of the wings from tip to tip, being, on the
other hand, as completely independent of use and disuse as is the growth of
the hair or wool on our long-haired dogs or long-woolled sheep.
To sum up: we may confidently admit that the length of the sternum, and
frequently the prominence of its crest, the length of the scapula and
furculum, have all been reduced in size in comparison with the same parts
in the rock-pigeon. And I presume that this may be attributed to disuse or
lessened exercise. The wings, as measured from the ends of the radii, have
likewise been generally reduced in length; but, owing to the increased
growth of the wing-feathers, the wings, from tip to tip, are commonly
longer than in the rock-pigeon. The feet, as well as the tarsi conjointly
with the middle toe, have likewise in most cases become reduced; and this
it is probable has been caused by their lessened use; but the existence of
some sort of correlation between the feet and beak is shown more plainly
than the effects of disuse. We have also some faint indication of a similar
correlation between the main bones of the wing and the beak.
SUMMARY ON THE POINTS OF DIFFERENCE BETWEEN THE SEVERAL DOMESTIC RACES, AND
BETWEEN THE INDIVIDUAL BIRDS.
The beak, together with the bones of the face, differ remarkably in length,
breadth, shape, and curvature. The skull differs in shape, and greatly in
the angle formed by the union of the pre-maxillary, nasal, and maxillo-
jugal bones. The curvature of the lower jaw and the reflection of its upper
margin, as well as the gape of the mouth, differ in a highly remarkable
manner. The tongue varies much in length, both independently and in
correlation with the length of the beak. The development of the naked,
wattled skin over the nostrils and round the eyes varies in an extreme
degree. The eyelids and the external orifices of the nostrils vary in
length, and are to a certain extent correlated with the degree of
development of the wattle. The size and form of the oesophagus and crop,
and their capacity for inflation, differ immensely. The length of the neck
varies. With the varying shape of the body, the breadth and number of the
ribs, the presence of processes, the number of the sacral vertebrae, and
the length of the sternum, all vary. The number and size of the coccygeal
vertebrae vary, apparently in correlation with the increased size of the
tail. The size and shape of the perforations in the sternum, and the size
and divergence of the arms of the furculum, differ. The oil-gland varies in
development, and is sometimes quite aborted. The direction and length of
certain feathers have been much modified, as in the hood of the Jacobin and
the frill of the Turbit. The wing and tail-feathers generally vary in
length together, but sometimes independently of each other and of the size
of the body. The number and position of the tail-feather vary to an
unparalleled degree. The primary and secondary wing-feathers occasionally
vary in number, apparently in correlation with the length of the wing. The
length of the leg and the size of the feet, and, in connection with the
latter, the number of the scutellae, all vary. A web of skin sometimes
connects the bases of the two inner toes, and almost invariably the two
outer toes when the feet are feathered.
The size of the body differs greatly: a Runt has been known to weigh more
than five times as much as a Short-faced Tumbler. The eggs differ in size
and shape. According to Parmentier (5/40. Temminck 'Hist. Nat. Gen. des
Pigeons et des Gallinaces' tome 1 1813 page 170.), some races use much
straw in building their nests, and others use little; but I cannot hear of
any recent corroboration of this statement. The length of time required for
hatching the eggs is uniform in all the breeds. The period at which the
characteristic plumage of some breeds is acquired, and at which certain
changes of colour supervene, differs. The degree to which the young birds
are clothed with down when first hatched is different, and is correlated in
a singular manner with the colour of the plumage. The manner of flight, and
certain inherited movements, such as clapping the wings, tumbling either in
the air or on the ground, and the manner of courting the female, present
the most singular differences. In disposition the several races differ.
Some races are very silent; others coo in a highly peculiar manner.
Although many different races have kept true in character during several
centuries, as we shall hereafter more fully see, yet there is far more
individual variability in the most constant breeds than in birds in a state
of nature. There is hardly any exception to the rule that those characters
vary most which are now most valued and attended to by fanciers, and which
consequently are now being improved by continued selection. This is
indirectly admitted by fanciers when they complain that it is much more
difficult to breed high fancy pigeons up to the proper standard of
excellence than the so-called toy pigeons, which differ from each other
merely in colour; for particular colours when once acquired are not liable
to continued improvement or augmentation. Some characters become attached,
from quite unknown causes, more strongly to the male than to the female
sex; so that we have in certain races, a tendency towards the appearance of
secondary sexual characters (5/41. This term was used by John Hunter for
such differences in structure between the males and females, as are not
directly connected with the act of reproduction, as the tail of the
peacock, the horns of deer, etc.) of which the aboriginal rock-pigeon
displays not a trace.
CHAPTER 1.VI.
PIGEONS--continued.
ON THE ABORIGINAL PARENT-STOCK OF THE SEVERAL DOMESTIC RACES.
HABITS OF LIFE.
WILD RACES OF THE ROCK-PIGEON.
DOVECOTE-PIGEONS.
PROOFS OF THE DESCENT OF THE SEVERAL RACES FROM COLUMBA LIVIA.
FERTILITY OF THE RACES WHEN CROSSED.
REVERSION TO THE PLUMAGE OF THE WILD ROCK-PIGEON.
CIRCUMSTANCES FAVOURABLE TO THE FORMATION OF THE RACES.
ANTIQUITY AND HISTORY OF THE PRINCIPAL RACES.
MANNER OF THEIR FORMATION.
SELECTION.
UNCONSCIOUS SELECTION.
CARE TAKEN BY FANCIERS IN SELECTING THEIR BIRDS.
SLIGHTLY DIFFERENT STRAINS GRADUALLY CHANGE INTO WELL-MARKED BREEDS.
EXTINCTION OF INTERMEDIATE FORMS.
CERTAIN BREEDS REMAIN PERMANENT, WHILST OTHERS CHANGE.
SUMMARY.
The differences described in the last chapter between the eleven chief
domestic races and between individual birds of the same race, would be of
little significance, if they had not all descended from a single wild
stock. The question of their origin is therefore of fundamental importance,
and must be discussed at considerable length. No one will think this
superfluous who considers the great amount of difference between the races,
who knows how ancient many of them are, and how truly they breed at the
present day. Fanciers almost unanimously believe that the different races
are descended from several wild stocks, whereas most naturalists believe
that all are descended from the Columba livia or rock-pigeon.
Temminck (6/1. Temminck 'Hist. Nat. Gen. des Pigeons' etc. tome 1 page
191.) has well observed, and Mr. Gould has made the same remark to me, that
the aboriginal parent must have been a species which roosted and built its
nest on rocks; and I may add that it must have been a social bird. For all
the domestic races are highly social, and none are known to build or
habitually to roost on trees. The awkward manner in which some pigeons,
kept by me in a summer-house near an old walnut-tree, occasionally alighted
on the barer branches, was evident. (6/2. I have heard through Sir C. Lyell
from Miss Buckley, that some half-bred Carriers kept during many years near
London regularly settled by day on some adjoining trees, and, after being
disturbed in their loft by their young being taken, roosted on them at
night.) Nevertheless, Mr. R. Scot Skirving informs me that he often saw
crowds of pigeons in Upper Egypt settling on low trees, but not on palms,
in preference to alighting on the mud hovels of the natives. In India Mr.
Blyth (6/3. 'Annals and Mag. of Nat. Hist.' 2nd series volume 20 1857 page
509; and in a late volume of the 'Journal of the Asiatic Society.') has
been assured that the wild C. livia, var. intermedia, sometimes roosts in
trees. I may here give a curious instance of compulsion leading to changed
habits: the banks of the Nile above lat. 28 deg 30' are perpendicular for a
long distance, so that when the river is full the pigeons cannot alight on
the shore to drink, and Mr. Skirving repeatedly saw whole flocks settle on
the water, and drink whilst they floated down the stream. These flocks seen
from a distance resembled flocks of gulls on the surface of the sea.
If any domestic race had descended from a species which was not social, or
which built its nest and roosted in trees (6/4. In works written on the
pigeon by fanciers I have sometimes observed the mistaken belief expressed
that the species which naturalists called ground-pigeons (in
contradistinction to arboreal pigeons) do not perch and build on trees. In
these same works by fanciers wild species resembling the chief domestic
races are often said to exist in various parts of the world; but such
species are quite unknown to naturalists.) the sharp eyes of fanciers would
assuredly have detected some vestige of so different an aboriginal habit.
For we have reason to believe that aboriginal habits are long retained
under domestication. Thus with the common ass we see signs of its original
desert life in its strong dislike to cross the smallest stream of water,
and in its pleasure in rolling in the dust. The same strong dislike to
cross a stream is common to the camel, which has been domesticated from a
very ancient period. Young pigs, though so tame, sometimes squat when
frightened, and thus try to conceal themselves even on an open and bare
place. Young turkeys, and occasionally even young fowls, when the hen gives
the danger-cry, run away and try to hide themselves, like young partridges
or pheasants, in order that their mother may take flight, of which she has
lost the power. The musk-duck (Cairina moschata) in its native country
often perches and roosts on trees (6/5. Sir R. Schomburgk in 'Journal R.
Geograph. Soc.' volume 13 1844 page 32.), and our domesticated musk-ducks,
though such sluggish birds, "are fond of perching on the tops of barns,
walls, etc., and, if allowed to spend the night in the hen-house, the
female will generally go to roost by the side of the hens, but the drake is
too heavy to mount thither with ease." (6/6. Rev. E.S. Dixon 'Ornamental
Poultry' 1848 pages 63, 66.) We know that the dog, however well and
regularly fed, often buries, like the fox, any superfluous food; and we see
him turning round and round on a carpet, as if to trample down grass to
form a bed; we see him on bare pavements scratching backwards as if to
throw earth over his excrement, although, as I believe, this is never
effected even where there is earth. In the delight with which lambs and
kids crowd together and frisk on the smallest hillock, we see a vestige of
their former alpine habits.
We have therefore good reason to believe that all the domestic races of the
pigeon are descended either from some one or from several species which
both roosted and built their nests on rocks, and were social in
disposition. As only five or six wild species have these habits, and make
any near approach in structure to the domesticated pigeon, I will enumerate
them.
[Firstly, the Columba leuconota resembles certain domestic varieties in its
plumage, with the one marked and never-failing difference of a white band
which crosses the tail at some distance from the extremity. This species,
moreover, inhabits the Himalaya, close to the limit of perpetual snow; and
therefore, as Mr. Blyth has remarked, is not likely to have been the parent
of our domestic breeds, which thrive in the hottest countries. Secondly,
the C. rupestris, of Central Asia, which is intermediate (6/7. 'Proc.
Zoolog. Soc.' 1859 page 400.) between the C. leuconota and livia; but has
nearly the same coloured tail as the former species. Thirdly, the Columba
littoralis builds and roosts, according to Temminck, on rocks in the
Malayan archipelago; it is white, excepting parts of the wing and the tip
of the tail, which are black; its legs are livid-coloured, and this is a
character not observed in any adult domestic pigeon; but I need not have
mentioned this species or the closely-allied C. luctuosa, as they in fact
belong to the genus Carpophaga. Fourthly, Columba guinea, which ranges from
Guinea (6/8. Temminck 'Hist. Nat. Gen. des Pigeons' tome 1; also 'Les
Pigeons' par Mme. Knip and Temminck. Bonaparte, however, in his 'Coup-
d'oeil' believes that two closely allied species are confounded together
under this name. The C. leucocephala of the West Indies is stated by
Temminck to be a rock-pigeon; but I am informed by Mr. Gosse that this is
an error.) to the Cape of Good Hope, and roosts either on trees or rocks,
according to the nature of the country. This species belongs to the genus
Strictoenas of Reichenbach, but is closely allied to Columba; it is to some
extent coloured like certain domestic races, and has been said to be
domesticated in Abyssinia; but Mr. Mansfield Parkyns, who collected the
birds of that country and knows the species, informs me that this is a
mistake. Moreover, the C. guinea is characterised by the feathers of the
neck having peculiar notched tips,--a character not observed in any
domestic race. Fifthly, the Columba oenas of Europe, which roosts on trees,
and builds its nest in holes, either in trees or the ground; this species,
as far as external characters go, might be the parent of several domestic
races; but, though it crosses readily with the true rock-pigeon, the
offspring, as we shall presently see, are sterile hybrids, and of such
sterility there is not a trace when the domestic races are intercrossed. It
should also be observed that if we were to admit, against all probability,
that any of the foregoing five or six species were the parents of some of
our domestic pigeons, not the least light would be thrown on the chief
differences between the eleven most strongly-marked races.
We now come to the best known rock-pigeon, the Columba livia, which is
often designated in Europe pre-eminently as the Rock-pigeon, and which
naturalists believe to be the parent of all the domesticated breeds. This
bird agrees in every essential character with the breeds which have been
only slightly modified. It differs from all other species in being of a
slaty-blue colour, with two black bars on the wings, and with the croup (or
loins) white. Occasionally birds are seen in Faroe and the Hebrides with
the black bars replaced by two or three black spots; this form has been
named by Brehm (6/9. 'Handbuch der Naturgesch. Vogel Deutschlands.') C.
amaliae, but this species has not been admitted as distinct by other
ornithologists. Graba (6/10. 'Tagebuch, Reise nach Faro' 1830 s. 62.) even
found a difference in the bars on the right and left wings of the same bird
in Faroe. Another and rather more distinct form is either truly wild or has
become feral on the cliffs of England and was doubtfully named by Mr. Blyth
(6/11. 'Annals and Mag. of Nat. Hist.' volume 19 1847 page 102. This
excellent paper on pigeons is well worth consulting.) as C. affinis, but is
now no longer considered by him as a distinct species. C. affinis is rather
smaller than the rock-pigeon of the Scottish islands, and has a very
different appearance owing to the wing-coverts being chequered with black,
with similar marks often extending over the back. The chequering consists
of a large black spot on the two sides, but chiefly on the outer side, of
each feather. The wing-bars in the true rock-pigeon and in the chequered
variety are, in fact, due to similar though larger spots symmetrically
crossing the secondary wing-feather and the larger coverts. Hence the
chequering arises merely from an extension of these marks to other parts of
the plumage. Chequered birds are not confined to the coasts of England; for
they were found by Graba at Faroe; and W. Thompson (6/12. 'Natural History
of Ireland' Birds volume 2 1850 page 11. For Graba see previous reference.)
says that at Islay fully half the wild rock-pigeons were chequered. Colonel
King, of Hythe, stocked his dovecote with young wild birds which he himself
procured from nests at the Orkney Islands; and several specimens, kindly
sent to me by him, were all plainly chequered. As we thus see that
chequered birds occur mingled with the true rock-pigeon at three distinct
sites, namely, Faroe, the Orkney Islands, and Islay, no importance can be
attached to this natural variation in the plumage.
Prince C.L. Bonaparte (6/13. 'Coup-d'oeil sur l'Ordre des Pigeons' 'Comptes
Rendus' 1854-55.), a great divider of species, enumerates, with a mark of
interrogation, as distinct from C. livia, the C. turricola of Italy, the C.
rupestris of Daouria, and the C. schimperi of Abyssinia; but these birds
differ from C. livia in characters of the most trifling value. In the
British Museum there is a chequered pigeon, probably the C. schimperi of
Bonaparte, from Abyssinia. To these may be added the C. gymnocyclus of G.R.
Gray from W. Africa, which is slightly more distinct, and has rather more
naked skin round the eyes than the rock-pigeon; but from information given
me by Dr. Daniell, it is doubtful whether this is a wild bird, for
dovecote-pigeons (which I have examined) are kept on the coast of Guinea.
The wild rock-pigeon of India (C. intermedia of Strickland) has been more
generally accepted as a distinct species. It differs chiefly in the croup
being blue instead of snow-white; but as Mr. Blyth informs me, the tint
varies, being sometimes albescent. When this form is domesticated chequered
birds appear, just as occurs in Europe with the truly wild C. livia.
Moreover we shall immediately have proof that the blue and white croup is a
highly variable character; and Bechstein (6/14. 'Naturgeschichte
Deutschlands' b. 4 1795 s. 14.) asserts that with dovecote-pigeons in
Germany this is the most variable of all the characters of the plumage.
Hence it may be concluded that C. intermedia cannot be ranked as
specifically distinct from C. livia.
In Madeira there is a rock-pigeon which a few ornithologists have suspected
to be distinct from C. livia. I have examined numerous specimens collected
by Mr. E.V. Harcourt and Mr. Mason. They are rather smaller than the rock-
pigeon from the Shetland Islands, and their beaks are plainly thinner, but
the thickness of the beak varied in the several specimens. In plumage there
is remarkable diversity; some specimens are identical in every feather (I
speak after actual comparison) with the rock-pigeon of the Shetland
Islands; others are chequered, like C. affinis from the cliffs of England,
but generally to a greater degree, being almost black over the whole back;
others are identical with the so-called C. intermedia of India in the
degree of blueness of the croup; whilst others have this part very pale or
very dark blue, and are likewise chequered. So much variability raises a
strong suspicion that these birds are domestic pigeons which have become
feral.
From these facts it can hardly be doubted that C. livia, affinis,
intermedia, and the forms marked with an interrogation by Bonaparte ought
all to be included under a single species. But it is quite immaterial
whether or not they are thus ranked, and whether some one of these forms or
all are the progenitors of the various domestic kinds, as far as any light
can thus be thrown on the differences between the more strongly-marked
races. That common dovecote-pigeons, which are kept in various parts of the
world, are descended from one or from several of the above-mentioned wild
varieties of C. livia, no one who compares them will doubt. But before
making a few remarks on dovecote-pigeons, it should be stated that the wild
rock-pigeon has been found easy to tame in several countries. We have seen
that Colonel King at Hythe stocked his dovecote more than twenty years ago
with young wild birds taken at the Orkney Islands, and since then they have
greatly multiplied. The accurate Macgillivray (6/15. 'History of British
Birds' volume 1 pages 275-284. Mr. Andrew Duncan tamed a rock-pigeon in the
Shetland Islands. Mr. James Barclay, and Mr. Smith of Uyea Sound, both say
that the wild rock-pigeon can be easily tamed; and the former gentleman
asserts that the tamed birds breed four times a year. Dr. Lawrence
Edmondstone informs me that a wild rock-pigeon came and settled in his
dovecote in Balta Sound in the Shetland Islands, and bred with his pigeons;
he has also given me other instances of the wild rock-pigeon having been
taken young and breeding in captivity.) asserts that he completely tamed a
wild rock-pigeon in the Hebrides; and several accounts are on records of
these pigeons having bred in dovecotes in the Shetland Islands. In India,
as Captain Hutton informs me, the wild rock-pigeon is easily tamed, and
breeds readily with the domestic kind; and Mr. Blyth (6/16. 'Annals and
Mag. of Nat. History' volume 19 1847 page 103 and volume for 1857 page
512.) asserts that wild birds come frequently to the dovecotes and mingle
freely with their inhabitants. In the ancient 'Ayeen Akbery' it is written
that, if a few wild pigeons be taken, "they are speedily joined by a
thousand others of their kind."
Dovecote-pigeons are those which are kept in dovecotes in a semi-
domesticated state; for no special care is taken of them, and they procure
their own food, except during the severest weather. In England, and,
judging from MM. Boitard and Corbie's work, in France, the common dovecote-
pigeon exactly resembles the chequered variety of C. livia; but I have seen
dovecotes brought from Yorkshire without any trace of chequering, like the
wild rock-pigeon of the Shetland Islands. The chequered dovecotes from the
Orkney Islands, after having been domesticated by Colonel King for more
than twenty years, differed slightly from each other in the darkness of
their plumage and in the thickness of their beaks; the thinnest beak being
rather thicker than the thickest one in the Madeira birds. In Germany,
according to Bechstein, the common dovecote-pigeon is not chequered. In
India they often become chequered, and sometimes pied with white; the croup
also, as I am informed by Mr. Blyth, becomes nearly white. I have received
from Sir. J. Brooke some dovecote-pigeons, which originally came from the
S. Natunas Islands in the Malay Archipelago, and which had been crossed
with the Singapore dovecotes: they were small and the darkest variety was
extremely like the dark chequered variety with a blue croup from Madeira;
but the beak was not so thin, though decidedly thinner than in the rock-
pigeon from the Shetland Islands. A dovecote-pigeon sent to me by Mr.
Swinhoe from Foochow, in China, was likewise rather small, but differed in
no other respect. I have also received through the kindness of Dr. Daniell,
four living dovecote-pigeons from Sierra Leone (6/17. Domestic pigeons of
the common kind are mentioned as being pretty numerous in John Barbut's
'Description of the Coast of Guinea' page 215 published in 1746; they are
said, in accordance with the name which they bear, to have been imported.)
these were fully as large as the Shetland rock-pigeon, with even bulkier
bodies. In plumage some of them were identical with the Shetland rock
pigeon, but with the metallic tints apparently rather more brilliant;
others had a blue croup, and resembled the chequered variety of C.
intermedia of India; and some were so much chequered as to be nearly black.
In these four birds the beak differed slightly in length, but in all it was
decidedly shorter, more massive, and stronger than in the wild rock-pigeon
from the Shetland Islands, or in the English dovecote. When the beaks of
these African pigeons were compared with the thinnest beaks of the wild
Madeira specimens, the contrast was great; the former being fully one-third
thicker in a vertical direction than the latter; so that any one at first
would have felt inclined to rank these birds as specifically distinct; yet
so perfectly graduated a series could be formed between the above-mentioned
varieties, that it was obviously impossible to separate them.]
To sum up: the wild Columba livia, including under this name C. affinis,
intermedia, and the other still more closely-affined geographical races,
has a vast range from the southern coast of Norway and the Faroe Islands to
the shores of the Mediterranean, to Madeira and the Canary Islands, to
Abyssinia, India, and Japan. It varies greatly in plumage, being in many
places chequered with black, and having either a white or blue croup or
loins; it varies also slightly in the size of the beak and body. Dovecote-
pigeons, which no one disputes are descended from one or more of the above
wild forms, present a similar but greater range of variation in plumage, in
the size of body, and in the length and thickness of the beak. There seems
to be some relation between the croup being blue or white, and the
temperature of the country inhabited by both wild and dovecote pigeons; for
nearly all the dovecote-pigeons in the northern parts of Europe have a
white croup, like that of the wild European rock-pigeon; and nearly all the
dovecote-pigeons of India have a blue croup like that of the wild C.
intermedia of India. As in various countries the wild rock-pigeon has been
found easy to tame, it seems extremely probable that the dovecote-pigeons
throughout the world are the descendants of at least two and perhaps more
wild stocks; but these, as we have just seen, cannot be ranked as
specifically distinct.
With respect to the variation of C. livia, we may without fear of
contradiction go one step further. Those pigeon-fanciers who believe that
all the chief races, such as Carriers, Pouters, Fantails, etc., are
descended from distinct aboriginal stocks, yet admit that the so-called
toy-pigeons, which differ from the rock-pigeon in little except colour, are
descended from this bird. By toy-pigeons are meant such birds as Spots,
Nuns, Helmets, Swallows, Priests, Monks, Porcelains, Swabians, Archangels,
Breasts, Shields, and others in Europe, and many others in India. It would
indeed be as puerile to suppose that all these birds are descended from so
many distinct wild stocks as to suppose this to be the case with the many
varieties of the gooseberry, heartsease, or dahlia. Yet these kinds all
breed true, and many of them include sub-varieties which likewise transmit
their character truly. They differ greatly from each other and from the
rock-pigeon in plumage, slightly in size and proportions of body, in size
of feet, and in the length and thickness of their beaks. They differ from
each other in these respects more than do dovecote-pigeons. Although we may
safely admit that dovecote-pigeons, which vary slightly, and that toy-
pigeons, which vary in a greater degree in accordance with their more
highly-domesticated condition, are descended from C. livia, including under
this name the above-enumerated wild geographical races; yet the question
becomes far more difficult when we consider the eleven principal races,
most of which have been profoundly modified. It can, however, be shown, by
indirect evidence of a perfectly conclusive nature, that these principal
races are not descended from so many wild stocks; and if this be once
admitted, few will dispute that they are the descendants of C. livia, which
agrees with them so closely in habits and in most characters, which varies
in a state of nature, and which has certainly undergone a considerable
amount of variation, as in the toy-pigeons. We shall moreover presently see
how eminently favourable circumstances have been for a great amount of
modification in the more carefully tended breeds.
The reasons for concluding that the several principal races are not
descended from so many aboriginal and unknown stocks may be grouped under
the following six heads:--
FIRSTLY.
If the eleven chief races have not arisen from the variation of some one
species, together with its geographical races, they must be descended from
several extremely distinct aboriginal species; for no amount of crossing
between only six or seven wild forms could produce races so distinct as
Pouters, Carriers, Runts, Fantails, Turbits, Short-faced Tumblers,
Jacobins, and Trumpeters. How could crossing produce, for instance, a
Pouter or a Fantail, unless the two supposed aboriginal parents possessed
the remarkable characters of these breeds? I am aware that some
naturalists, following Pallas, believe that crossing gives a strong
tendency to variation, independently of the characters inherited from
either parent. They believe that it would be easier to raise a Pouter or
Fantail pigeon from crossing two distinct species, neither of which
possessed the characters of these races, than from any single species. I
can find few facts in support of this doctrine, and believe in it only to a
limited degree; but in a future chapter I shall have to recur to this
subject. For our present purpose the point is not material. The question
which concerns us is, whether or not many new and important characters have
arisen since man first domesticated the pigeon. On the ordinary view,
variability is due to changed conditions of life; on the Pallasian
doctrine, variability, or the appearance of new characters, is due to some
mysterious effect from the crossing of two species, neither of which
possesses the characters in question. In some few instances it is possible
that well-marked races may have been formed by crossing; for instance, a
Barb might perhaps be formed by a cross between a long-beaked Carrier,
having large eye-wattles, and some short-beaked pigeon. That many races
have been in some degree modified by crossing, and that certain varieties
which are distinguished only by peculiar tints have arisen from crosses
between differently-coloured varieties, is almost certain. On the doctrine,
therefore, that the chief races owe their differences to their descent from
distinct species, we must admit that at least eight or nine, or more
probably a dozen species, all having the same habit of breeding and
roosting on rocks and living in society, either now exist somewhere, or
formerly existed, but have become extinct as wild birds. Considering how
carefully wild pigeons have been collected throughout the world, and what
conspicuous birds they are, especially when frequenting rocks, it is
extremely improbable that eight or nine species, which were long ago
domesticated and therefore must have inhabited some anciently known
country, should still exist in the wild state and be unknown to
ornithologists.
The hypothesis that such species formerly existed, but have become extinct,
is in some slight degree more probable. But the extinction of so many
species within the historical period is a bold hypothesis, seeing how
little influence man has had in exterminating the common rock-pigeon, which
agrees in all its habits of life with the domestic races. The C. livia now
exists and flourishes on the small northern islands of Faroe, on many
islands off the coast of Scotland, on Sardinia, and the shores of the
Mediterranean, and in the centre of India. Fanciers have sometimes imagined
that the several supposed parent-species were originally confined to small
islands, and thus might readily have been exterminated; but the facts just
given do not favour the probability of their extinction, even on small
islands. Nor is it probable, from what is known of the distribution of
birds, that the islands near Europe should have been inhabited by peculiar
species of pigeons; and if we assume that distant oceanic islands were the
homes of the supposed parent-species, we must remember that ancient voyages
were tediously slow, and that ships were then ill-provided with fresh food,
so that it would not have been easy to bring home living birds. I have said
ancient voyages, for nearly all the races of the pigeon were known before
the year 1600, so that the supposed wild species must have been captured
and domesticated before that date.
SECONDLY.
The doctrine that the chief domestic races are descended from several
aboriginal species, implies that several species were formerly so
thoroughly domesticated as to breed readily when confined. Although it is
easy to tame most wild birds, experience shows us that it is difficult to
get them to breed freely under confinement; although it must be owned that
this is less difficult with pigeons than with most other birds. During the
last two or three hundred years, many birds have been kept in aviaries, but
hardly one has been added to our list of thoroughly reclaimed species: yet
on the above doctrine we must admit that in ancient times nearly a dozen
kinds of pigeons, now unknown in the wild state, were thoroughly
domesticated.
THIRDLY.
Most of our domesticated animals have run wild in various parts of the
world; but birds, owing apparently to their partial loss of the power of
flight, less often than quadrupeds. Nevertheless I have met with accounts
showing that the common fowl has become feral in South America and perhaps
in West Africa, and on several islands: the turkey was at one time almost
feral on the banks of the Parana; and the Guinea-fowl has become perfectly
wild at Ascension and in Jamaica. In this latter island the peacock, also,
"has become a maroon bird." The common duck wanders from its home and
becomes almost wild in Norfolk. Hybrids between the common and musk-duck
which have become wild have been shot in North America, Belgium, and near
the Caspian Sea. The goose is said to have run wild in La Plata. The common
dovecote-pigeon has become wild at Juan Fernandez, Norfolk Island,
Ascension, probably at Madeira, on the shores of Scotland, and, as is
asserted, on the banks of the Hudson in North America. (6/18. With respect
to feral pigeons--for Juan Fernandez see Bertero in 'Annal. des Sc. Nat.'
tome 21 page 351. For Norfolk Islands see Rev. E.S. Dixon in the 'Dovecote'
1851 page 14 on the authority of Mr. Gould. For Ascension I rely on MS.
information given me by Mr. Layard. For the banks of the Hudson, see Blyth
in 'Annals of Nat. Hist.' volume 20 1857 page 511. For Scotland see
Macgillivray 'British Birds' volume 1 page 275; also Thompson 'Nat. Hist.
of Ireland, Birds' volume 2 page 11. For ducks see Rev. E.S. Dixon
'Ornamental Poultry' 1847 page 122. For the feral hybrids of the common and
musk-ducks see Audubon 'American Ornithology' and Selys-Longchamp 'Hybrides
dans la Famille des Anatides.' For the goose Isidore Geoffroy St.-Hilaire
'Hist. Nat. Gen.' tome 3 page 498. For guinea-fowls see Gosse 'Naturalist's
Sojourn in Jamaica' page 124; and his 'Birds of Jamaica' for fuller
particulars. I saw the wild guinea-fowl in Ascension. For the peacock see
'A Week at Port Royal' by a competent authority, Mr. R. Hill, page 42. For
the turkey I rely on oral information; I ascertained that they were not
Curassows. With respect to fowls I will give the references in the next
chapter.) But how different is the case, when we turn to the eleven chief
domestic races of the pigeon, which are supposed by some authors to be
descended from so many distinct species! no one has ever pretended that any
one of these races has been found wild in any quarter of the world; yet
they have been transported to all countries, and some of them must have
been carried back to their native homes. On the view that all the races are
the product of variation, we can understand why they have not become feral,
for the great amount of modification which they have undergone shows how
long and how thoroughly they have been domesticated; and this would unfit
them for a wild life.
FOURTHLY.
If it be assumed that the characteristic differences between the various
domestic races are due to descent from several aboriginal species, we must
conclude that man chose for domestication in ancient times, either
intentionally or by chance, a most abnormal set of pigeons; for that
species resembling such birds as Pouters, Fantails, Carriers, Barbs, Short-
faced Tumblers, Turbits, etc., would be in the highest degree abnormal, as
compared with all the existing members of the great pigeon family, cannot
be doubted. Thus we should have to believe that man not only formerly
succeeded in thoroughly domesticating several highly abnormal species, but
that these same species have since all become extinct, or are at least now
unknown. This double accident is so extremely improbable that the assumed
existence of so many abnormal species would require to be supported by the
strongest evidence. On the other hand, if all the races are descended from
C. livia, we can understand, as will hereafter be more fully explained, how
any slight deviation in structure which first appeared would continually be
augmented by the preservation of the most strongly marked individuals; and
as the power of selection would be applied according to man's fancy, and
not for the bird's own good, the accumulated amount of deviation would
certainly be of an abnormal nature in comparison with the structure of
pigeons living in a state of nature.
I have already alluded to the remarkable fact that the characteristic
differences between the chief domestic races are eminently variable; we see
this plainly in the great difference in the number of the tail-feathers in
the Fantail, in the development of the crop in Pouters, in the length of
the beak in Tumblers, in the state of the wattle in Carriers, etc. If these
characters are the result of successive variations added together by
selection, we can understand why they should be so variable: for these are
the very parts which have varied since the domestication of the pigeon, and
therefore would be likely still to vary; these variations moreover have
been recently, and are still being accumulated by man's selection;
therefore they have not as yet become firmly fixed.
FIFTHLY.
All the domestic races pair readily together, and, what is equally
important, their mongrel offspring are perfectly fertile. To ascertain this
fact I made many experiments, which are given in the note below; and
recently Mr. Tegetmeier has made similar experiments with the same result.
(6/19. I have drawn out a long table of the various crosses made by
fanciers between the several domestic breeds but I do not think it worth
while publishing. I have myself made for this special purpose many crosses,
and all were perfectly fertile. I have united in one bird five of the most
distinct races, and with patience I might undoubtedly have thus united all.
The case of five distinct breeds being blended together with unimpaired
fertility is important, because Gartner has shown that it is a very
general, though not, as he thought, universal rule, that complex crosses
between several species are excessively sterile. I have met with only two
or three cases of reported sterility in the offspring of certain races when
crossed. Pistor ('Das Ganze der Feldtaubenzucht' 1831 s. 15) asserts that
the mongrels from Barbs and Fantails are sterile: I have proved this to be
erroneous, not only by crossing those hybrids with several other hybrids of
the same parentage, but by the more severe test of pairing brother and
sister hybrids inter se, and they were PERFECTLY fertile. Temminck has
stated ('Hist. Nat. Gen. des Pigeons' tome 1 page 197) that the Turbit or
Owl will not cross readily with other breeds: but my Turbits crossed, when
left free with Almond Tumblers and with Trumpeters; the same thing has
occurred (Rev. E.S. Dixon 'The Dovecote' page 107) between Turbits and
Dovecotes and Nuns. I have crossed Turbits with Barbs, as has M. Boitard
(page 34), who says the hybrids were very fertile. Hybrids from a Turbit
and Fantail have been known to breed inter se (Riedel 'Taubenzucht' s. 25
and Bechstein 'Naturgesch. Deutsch.' b. 4 s. 44. Turbits (Riedel s. 26)
have been crossed with Pouters and with Jacobins, and with a hybrid
Jacobin-trumpeter (Riedel s. 27). The latter author has, however, made some
vague statements (s. 22) on the sterility of Turbits when crossed with
certain other crossed breeds. But I have little doubt that the Rev. E.S.
Dixon's explanation of such statements is correct, viz. that individual
birds both with Turbits and other breeds are occasionally sterile.) The
accurate Neumeister asserts that when dovecotes are crossed with pigeons of
any other breed, the mongrels are extremely fertile and hardy. (6/20. 'Das
Ganze der Taubenzucht' s. 18.) MM. Boitard and Corbie (6/21. 'Les Pigeons'
etc. page 35.) affirm, after their great experience, that the more distinct
the breeds are which are crossed, the more productive are their mongrel
offspring. I admit that the doctrine first broached by Pallas is highly
probable, if not actually proved, namely, that closely allied species,
which in a state of nature or when first captured would have been in some
degree sterile if crossed, lose this sterility after a long course of
domestication; yet when we consider the great difference between such races
as Pouters, Carriers, Runts, Fantails, Turbits, Tumblers etc., the fact of
their perfect, or even increased, fertility when intercrossed in the most
complicated manner becomes a strong argument in favour of their having all
descended from a single species. This argument is rendered much stronger
when we hear (I append in a note (6/22. Domestic pigeons pair readily with
the allied C. oenas (Bechstein 'Naturgesch. Deutschlands' b. 4 s. 3); and
Mr. Brent has made the same cross several times in England, but the young
were very apt to die at about ten days old; one hybrid which he reared
(from C. oenas and a male Antwerp Carrier) paired with a Dragon, but never
laid eggs. Bechstein further states (s. 26) that the domestic pigeon will
cross with C. palumbus, Turtur risoria and T. vulgaris, but nothing is said
of the fertility of the hybrids, and this would have been mentioned had the
fact been ascertained. In the Zoological Gardens (MS. report to me from Mr.
James Hunt) a male hybrid from Turtur vulgaris and a domestic pigeon
"paired with several different species of pigeons and doves, but none of
the eggs were good." Hybrids from C. oenas and gymnophthalmos were sterile.
In Loudon's 'Mag. of Nat. Hist.' volume 7 1834 page 154 it is said that a
male hybrid (from Turtur vulgaris male, and the cream-coloured T. risoria
female) paired during two years with a female T. risoria, and the latter
laid many eggs, but all were sterile. MM. Boitard and Corbie ('Les Pigeons'
page 235) state that the hybrids from these two turtle-doves are invariably
sterile both inter se and with either pure parent. The experiment was tried
by M. Corbie "avec une espece d'obstination;" and likewise by M. Mauduyt,
and by M. Vieillot. Temminck also found the hybrids from these two species
quite barren. Therefore, when Bechstein ('Naturgesch. Deutschlands Vogel'
b. 4 s. 101) asserts that the hybrids from these two turtle-doves propagate
inter se equally well with pure species, and when a writer in the 'Field'
newspaper (in a letter dated November 10th, 1858) makes a similar
assertion, it would appear that there must be some mistake; though what the
mistake is I know not, as Bechstein at least must have known the white
variety of T. risoria: it would be an unparalleled fact if the same two
species sometimes produced EXTREMELY fertile, and sometimes EXTREMELY
barren, offspring. In the MS. report from the Zoological Gardens it is said
that hybrids from Turtur vulgaris and suratensis, and from T. vulgaris and
Ectopistes migratorius, were sterile. Two of the latter male hybrids paired
with their pure parents, viz. Turtur vulgaris and the Ectopistes, and
likewise with T. risoria and with Columba oenas, and many eggs were
produced, but all were barren. At Paris, hybrids have been raised (Isid.
Geoffrey Saint-Hilaire 'Hist. Nat. Generale' tome 3 page 180) from Turtur
auritus with T. cambayensis and with T. suratensis; but nothing is said of
their fertility. At the Zoological Gardens of London the Goura coronata and
victoriae produced a hybrid which paired with the pure G. coronata, and
laid several eggs, but these proved barren. In 1860 Columba gymnophthalmos
and maculosa produced hybrids in these same gardens.) all the cases which I
have collected) that hardly a single well-ascertained instance is known of
hybrids between two true species of pigeons being fertile, inter se, or
even when crossed with one of their pure parents.
SIXTHLY.
Excluding certain important characteristic differences, the chief races
agree most closely both with each other and with C. livia in all other
respects. As previously observed, all are eminently sociable; all dislike
to perch or roost, and refuse to build in trees; all lay two eggs, and this
is not a universal rule with the Columbidae; all, as far as I can hear,
require the same time for hatching their eggs; all can endure the same
great range of climate; all prefer the same food, and are passionately fond
of salt; all exhibit (with the asserted exception of the Finnikin and
Turner which do not differ much in any other character) the same peculiar
gestures when courting the females; and all (with the exception of
Trumpeters and Laughers, which likewise do not differ much in any other
character) coo in the same peculiar manner, unlike the voice of any other
wild pigeon. All the coloured breeds display the same peculiar metallic
tints on the breast, a character far from general with pigeons. Each race
presents nearly the same range of variation in colour; and in most of the
races we have the same singular correlation between the development of down
in the young and the future colour of plumage. All have the proportional
length of their toes, and of their primary wing-feathers, nearly the same,-
-characters which are apt to differ in the several members of the
Columbidae. In those races which present some remarkable deviation of
structure, such as in the tail of Fantails, crop of Pouters, beak of
Carriers and Tumblers, etc., the other parts remain nearly unaltered. Now
every naturalist will admit that it would be scarcely possible to pick out
a dozen natural species in any family which should agree closely in habits
and in general structure, and yet should differ greatly in a few characters
alone. This fact is explicable through the doctrine of natural selection;
for each successive modification of structure in each natural species is
preserved, solely because it is of service; and such modifications when
largely accumulated imply a great change in the habits of life, and this
will almost certainly lead to other changes of structure throughout the
whole organisation. On the other hand, if the several races of the pigeon
have been produced by man through selection and variation, we can readily
understand how it is that they should still all resemble each other in
habits and in those many characters which man has not cared to modify,
whilst they differ to so prodigious a degree in those parts which have
struck his eye or pleased his fancy.
Besides the points above enumerated, in which all the domestic races
resemble C. livia and each other, there is one which deserves special
notice. The wild rock-pigeon is of a slaty-blue colour; the wings are
crossed by two bars; the croup varies in colour, being generally white in
the pigeon of Europe, and blue in that of India; the tail has a black bar
close to the end, and the outer webs of the outer tail-feathers are edged
with white, except near the tips. These combined characters are not found
in any wild pigeon besides C. livia. I have looked carefully through the
great collections of pigeons in the British Museum, and I find that a dark
bar at the end of the tail is common; that the white edging to the outer
tail-feathers is not rare; but that the white croup is extremely rare, and
the two black bars on the wings occur in no other pigeon, excepting the
alpine C. leuconota and C. rupestris of Asia. Now if we turn to the
domestic races, it is highly remarkable, as an eminent fancier, Mr.
Wicking, observed to me, that, whenever a blue bird appears in any race,
the wings almost invariably show the double black bars. (6/23. There is one
exception to the rule, namely, in a sub-variety of the Swallow of German
origin, which is figured by Neumeister, and was shown to me by Mr. Wicking.
This bird is blue, but has not the black wing-bars; for our object,
however, in tracing the descent of the chief races, this exception
signifies the less as the Swallow approaches closely in structure to C.
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