COURTSHIPS OF LABRADOR BIRDS 
and then returned to its normal position. All 
this the drake does swimming near the duck, 
often facing her in his eagerness, while she 
floats about indifferently, or at times shows her 
interest and appreciation by facing him and 
throwing up her head a little in a gentle imita- 
tion of his forcefulness.' 
Another duck whose courtship antics are 
even more interesting than those of the eider is 
the American golden-eye or whistler, the plon- 
* Abbott H. Thayer’s statement in the Introduction to 
Gerald H. Thayer’s wonderfully interesting book on 
“Concealing-Coloration in the Animal Kingdom” that 
“This discovery that patterns and utmost contrasts of 
colour (not to speak of appendages) on animals make 
wholly for their ‘ obliteration,’ is a fatal blow to the vari- 
ous theories that these patterns exist mainly as nuptial 
dress, warning colours, mimicry devices (i. ¢., mimicry of 
one species by another), etc., since these are all attempts 
to explain an entirely false conception that such patterns 
make their wearers conspicuous? seems to me hard to 
believe in the case of the male eider. I have watched this 
bird on land, on water and in the air, on rocks, in bogs 
and among bushes both green and brown, among icebergs 
and ice floes, and, if I were a gyrfalcon intent on eider 
flesh, I should not wish for a more conspicuous mark. I 
can not help thinking that the brilliant orange-yellow legs 
of the male golden-eye, the vivid blue lining of the mouth 
of the double-crested cormorant and the wonderful black 
belly-shield of the male eider are instances of the work- 
ings of sexual selection. 
89 
