Vol. XIV 
: ee ethane Lee ee 
ray THompson, Directive Coloration of Birds. 395 
DIRECIIVE, COLORATION OF BIRDS. 
BY ERNEST SETON THOMPSON. 
Flate IV. 
Tue Protective Coloration of Birds has been much studied of 
late, but I do not know of any paper treating of their Directive 
Coloration. 
While living on the Plains in the eighties, I made many studies, 
or as I then called them ‘flying descriptions’ of birds, and on 
putting these together recently in a methodic scheme I arrived 
at a few general principles that may prove of interest. 
I can best illustrate by taking an example from mammals. 
The common jack rabbit when squatting under a sage-bush is 
simply a sage-gray lump without distinctive color or form. Its 
color in particular is wholly protective, and it is usually accident 
rather than sharpness of vision which betrays the creature as it 
squats. But the moment it springs, it is wholly changed. It is 
difficult to realize that this is the same animal. It bounds away 
with erect ears, showing the black and white markings on their 
back and under side. The black nape is exposed, the tail is 
carried straight down, exposing its black upper part surrounded 
by a region of snowy white ; its legs and belly show clear white, 
and everything that sees it is plainly notified that this zs a sack 
rabbi. The coyote, the fox, the wolf, the badger, etc., realize 
that it is useless to follow; the cottontail, the jumping rat, the 
fawn, the prairie dog, etc., that it is needless to flee; the young 
jack rabbit, that this is its near relative, and the next jack rabbit 
that this may be its mate. And thus, though incidentally useful 
to other species at times, the sum total of all this clear labelling 
is vastly serviceable to the jack rabbit and saves it much pains 
to escape from real or imaginary dangers. 
As soon as it squats again all the directive marks disappear 
and the protective gray alone is seen. 
In the bird world the same general rule applies. When sitting, 
birds are protectively colored ; when (ying, directively. 
