116 
SEXUAL SELECTION : BIRDS. 
Paet II. 
to ; but in many of these cases the birds were allowed 
to range freely over large ponds, and there is no reason 
to suppose that they were unnaturally stimulated by 
high feeding. 
With respect to birds in a state of nature, the first 
and most obvious supposition which will occur to every- 
one is that the female at the proper season accepts the 
first male whom she may encounter; but she has at 
least the opportunity for exerting a choice, as she is 
almost invariably pursued by many males. Audubon 
— and we must remember that he spent a long life in 
prowling about the forests of the United States and 
observing the birds — does not doubt that the female 
deliberately chooses her mate ; thus, speaking of a wood- 
pecker, he says the hen is followed by half-a-dozen gay 
suitors, who continue performing strange antics, until 
a marked preference is shewn for one.” The female of 
the red-winged starling (Agelseus phoeniceus) is likewise 
pursued by several males, until, becoming fatigued, 
“ she alights, receives their addresses, and soon makes 
a choice.” He describes also how several male night- 
jars repeatedly plunge through the air with astonish- 
ing rapidity, suddenly turning, and thus making a 
singular noise ; but no sooner has the female made 
her choice, than the other males are driven away.” 
With one of the vultures (Gathartes aura) of the United 
States, parties of eight or ten or more males and females 
assemble on fallen logs, exhibiting the strongest desire 
to please mutually,” and after many caresses, each male 
leads off his partner on the wing. Audubon likewise 
carefully observed the wild flocks of Canada geese (Anser 
Canadensis)^ and gives a graphic description of their 
love-antics ; he says that the birds which had been pre- 
viously mated renewed their courtship as early as the 
month of January, w^hile the others would be contend- 
