Bird lore - Project Puffin

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Theories of the Origin of Birds. By
William K. Gregory. Annals of the
New York Academy of Sciences, Vol.
XXVII, pp. 31-38. New York. Published
by the Academy, May 4, 1916.
In this paper, Dr. Gregory, starting
with the demonstrated fact that birds arc
of reptilian origin, has summarized, from
the point of view of comparative anatomy,
palaeontological knowledge and inference
concerning the ancestors of Arclucoplcryx,
'the oldest known fossil bird, of the Jurassic
period.' He favors the hypothesis that
birds were evolved from 'Pseudosuchian'
reptiles of the Permian and Trias, from
which also came the specialized dinosaurs,
pterosaurs, etc. (reference to the work of
Dr. Robert Broon). The highly special-
ized avian hind limbs and bipedal loco-
motion were acquired by terrestrial or
arboreal forms before the complete spe-
cialization of the fore limbs for flight
(reference to the work of Prof. H. F.
Osborn and Baron Francis Nopcsa).
Feathers, from specialized scales (reference
to the work of Mr. W. P. Pycraft), and the
power of flight arose in very active rep-
tilian animals. High stable blood-heat,
correlated with this activity, was con-
served by feathers. Development of the
feathers of the wing to brace against the
air augmented the considerable activity of
the already bird-like reptile and launched
it on its initial flight as the 'first bird.'
A recent interesting paper by Mr. C. W.
Beebe is spoken of, according to which 'in
the young of various species of doves,
pigeons, jacanas and owls there is a
reduced pelvic wing,' and Dr. Gregory
disposes of the hypothesis of a dual origin
for birds as 'in the writer's judgment, en-
tirely untenable.'
Dr. Gregory has taken up the problem
of the evolution of the bird in connection
with a Columbia University course on
vertebrate development, and his paper will
be especially useful to the general student
because of its concisensess, conservatism
and forcefulness. It gives a sound basis
(253)
for investigation on avian ancestry. Many
of the facts presented are not new. Prob-
ably they have never been so carefully
balanced nor so successfully interpreted.
One of the chief bones of contention is
whether flight first evolved among bipedal,
leaping, terrestrial animals or among par-
achuting, arboreal ones. Kx|K)nents of
both theories arc (juotcd at length, and the
author, while himself favoring the hypoth-
esis of arboreal ancestry, is not convinced
that the ancestors of birds 'held the arms
perfectly still throughout the gliding leap.'
His bridge of hypothesis from reptile to
bird inspires confidence, and should hold
well until intermediate fossils are unearthed
to render it no longer necessary.—
J. T. N.
Some Bird Friends. By Henry F.
PuLLEN. Published by the Free Lance
Publishing Company, Victoria, British
Columbia, Canada. Printed and compiled
at the Oak Bay Print Shop, Victoria.
30 pages. 20 illustrations from
original photographs.
This attractive booklet is 'An intimate
introduction to a few of the common birds
of Western Canada,' and it should, as the
author hopes, help its readers to an interest,
or a further interest, in bird-life. Some
of Mr. Pullen's 'common birds,' such as
the White-crowned Sparrow and Pigeon
Guillemot, are rare or but names to most
easterners, and are pleasantly and inter-
estingly introduced. It is interesting to
know of a place where Crows nest several
hundred pairs to the acre, and that Sky-
larks have been successfully acclimatized
in British Columbia. A vireo is described
as 'a little larger than the flycatcher,'
which is, to say the least, vague, as the
flycatchers of British Columbia range
from under si.x to over nine inches in
length, and of course no vireo approaches
the latter size. The author has had the
good fortune of watching a 'Blue Grouse'
(meaning the local form of the Dusky
Grouse) hoot, but the answer came doubt-
less not from the bird's mate but from a