FALCO CANDICANS, J. F. Gmel.

Greenland Falcon, dark race.

 

np 0 a a c ele a : : e
Tur birds figured on the two accompanying Plates differ from both the white or true Falco candicans aud
the F. 2slandus, and moreover are so inconstant in their markir

igs that I have never seen two specimens
that had the tail similarly marked ;

for while the barrings of the feathers are perfec
are interrupted. In one the second and third feathers from the
the same feathers may be more or less barred. A

t in one, in another they
middle ones may be wholly white ; in another
degree of inconstancy also occurs in the markings of
the back and wings, although generally to a less extent ; but the young of the year of the white / candicans
and the young of this dark race assimilate in being lightly coloured, in which respect they offer a decided
eyrfalco and F. islandus, which at the same period of their existence are
both dark. By some persons it may be supposed that the individuals of the dark
plumage as they advance in age, and ultimately become white; but if the
who have paid special attention to these Falcons, that the plumage they
carried throughout life, be correct, this will not be the case ;

contrast to the young of Falco

race change their
assertion of those ornithologists
assume at their second moult is
and that this theory is the true one would seem
to be confirmed by the fact that a Greenland Falcon which lived for some years in the Gardens of the
Zoological Society never exhibited any subsequent change. Professor Newton states

that the true
Icelander is believed to breed in the southern parts of Greenland.

If this is the case, it appears to me
probable that this dark or mongrel race may be due to the interbreeding of I. islandus and F. candicans,
in which event the progeny would naturally be intermediate in colour and markings. As an instance in
point I may cite the results of a cross between our two species of Pheasants (Phasianus colchicus and
P. torquatus), the progeny of which not only differ in their plumage from the parent stocks, but even as
compared with one another. If this is not the cause of the abnormal state of plumage of these Falcons,
Tam at a loss to account for it. I may mention that these strongly marked birds appear to be more
exclusively natives of South Greenland, and that it is from the Danish settlements in that country that
specimens are sent to Kurope. It is the young of these indistinctly marked birds that most frequently visit
Britain, of which Lord Cawdor’s specimen, now in the British Museum, is an example, and is represented in
the second figure, or young of the dark race, in the accompanying Plate.

Whether these noble Falcons have all sprang from one stock is a question not easily answered ; neither is it
easy to say, in that case, which most approximates to the common progenitor ; but we may, I think,
fairly conclude that it must have been the Falco candicans in its whitest and purest state, inasmuch as it is the
bird which inhabits the highest northern regions, or the icebound portions of the arctic zone. Geologists will
tell us that, in ages gone by, Iceland and Northern Europe were in the same state, and that glaciers, instead
of the peaty morasses which now exist, then prevailed. May not the physical changes that have taken place
in more recent periods have had an influence on the colouring of these Falcons? That such a change has
been effected in the case of the common Grouse (Lagopus scoticus) I feel assured, inasmuch as I find no
difference, except that of colour, between it and the white Lagopus saliceti of Norway and America. To
assert positively that the milder atmosphere of our more humid Seu-eme islands, and their more ro and
heathery soil, is the cause of the difference in colour between the two birds, would perbaps be speaking too:
strongly ; yet I think it probable that such a theory would be the right one.

Those who have studied the birds of the world in their entirety must have been struck with the fact
that, while certain forms are abundant in one portion of the globe, they are totally absent from the opposite
one. For instance, in the northern or arctic hemisphere Auks, Puffins, and Guillemots abound, while none
of these forms are to be found in the opposite or southern hemisphere, their place there being oeeo ee by
Penguins and Albatrosses. ‘This is not easily to be accounted DD Snes: on the other band, Cormorants
haunt the sea-girt rocks of every part of the globe, and Gulls ag oui are no less universally dispersed.
This absence of certain forms, again, from countries not very far distant fom those in Mt ad One are
numerous is further exemplified in the fact that, while there are ert es Swallows nor Crows in NGS Zealand,
Norfolk Island, or perhaps the whole of Polynesia, Swallows, Martins, and a are abundant in Australia,
and Crows are as numerous there as in any other country—all, fomencr) being specials different from the
birds thus called which inhabit the same latitudes in the northern hemisphere. Ware it necessary, other
instances of this apparent limitation of species in certain parts of the globe might be cited almost ad
infinitum; and we might theorize to a similar extent as to ” ac ania nee ee
well as Australia, or why Swallows should be plentiful in the one c My

a Crow should not inhabit New Zealand as