12 
THE CONDOR 
Vol. XV 
on the nest. If the purpose of the difference between male and female is to lead 
enemies from the nest it would be a protective device, but certainly not a case of 
concealing coloration, so far as the male is concerned. The doctrines of warning- 
colors, and mimicry, besides the lack of convincing evidence of their validity, ap- 
pear to admit that all color patterns are not concealing. 
Another set of inconsistencies includes the croaks of frogs, the songs of birds 
and the cries of mammals. Why should nature provide concealing colors for a 
pika, a woodchuck, or a prairie-dog, and then endow it with an instinct which in- 
duces it to attract the attention of every enemy which approaches? Everyone 
who has studied nature in the field must know that a large percentage of birds 
and mammals which are observed, either by man or by lower animals, would es- 
cape observation, if, to use the vernacular, they “had sense enough to keep their 
mouths shut” and remain motionless. These cries, croaks and songs are not for 
the purpose of leading enemies away from nests or young, because they are not 
confined to one sex or to the breeding season. 
To take care of the seeming exceptions to the concealing coloration doctrine 
it has been boldly asserted that “all patterns and colors, upon all animals whatso- 
ever, except such as live in the dark, or are neither predatory nor preyed upon, are, 
when seen against the background against which their enemy (or prey) would see 
them at the critical moment, inexpressibly perfect pictures of the background, and 
therefore obliteratively colored.” The circumstances of the critical moments of 
most species vary so enormously, and such moments occur in varying circum- 
stances so often with some species, that it is difficult to conceive how anyone at all 
familiar with nature could indulge in such a statement. It is cjuite on a level with 
another assertion of the same author, that “one may read on an animal’s coat the 
main facts of his habits and habitat, without ever seeing him in his home.” As 
the crow’s color does not change, does it display “a perfect picture of the back- 
ground” when the critical moment occurs in a cornfield, or in a cottonwood tree, 
or on the rock crags of the Rabbit Ears, or when the ground is bare, or when it 
is white with snow? If it be suggested that it is when on the nest, the obvious 
answer is that the nesting sites vary greatly, and surely that suggestion could not 
apply to the same query concerning the male of the redwing, or any species whose 
male takes no part in nest building or brooding. A moment’s thought must flood 
the mind of every zoologist with specific objections to the assertions above quot- 
ed. 
The critical moment theory has been particularly applied to those animals 
which have white rump patches or white tails, or both. I have been familiar with 
the prong-horn antelope since 1883 and with the rabbits for a much longer peri- 
od, and have never seen either dog or coyote puzzled for a second by the fact 
that the posterior white parts were thrown against a sky and so obliterated. Dur- 
ing the past two seasons I have had more opportunities to watch dogs pursue 
cottontails and jackrabbits than ever before, and they followed unerringly, often 
at close range, up hill where the rabbits were almost constantly against the sky. 
In case of the antelope, it is, so far as my observation goes, usually the flashing of 
the white patch that attracts the attention of its enemy, whether man or beast. 
It is inconceivable that nature has provided it with such a distinctive advertis- 
ing character, to attract the attention of all the coyotes in the vicinity, merely in 
order that it might sometimes be seen against a white sky and thus throw the 
enemy off the trail, even if we can presume that the animal’s enemies pursue their 
prey entirely by sight. My own observation is that most of our forest rabbits 
are not seen usually against a sky background, or even a forest background with 
