CONCORD. 
1910 
May 19 
Sexual act 
of Phoebes 
On May 12th I visited the cellar under the little 
shop on the Ritchie place, finding there a Phoebe’s nest 
with four eggs. I examined the nest again yesterday after¬ 
noon when it held five eggs. On both occasions the eggs 
were cold. On neither did I see or hear a bird about the 
place. But as I was approaching the shed this afternoon 
(about 5 o’clock) a Phoebe came flying swiftly towards me 
from the direction of the cellar, closely followed by 
another. After several sharp turns and twists, the two 
birds came together in the air at a height of about 15 
feet and thence descended fcather slowly to the earth, clinched 
together and whirling around and around. 
At first I thought it was a fight between rival 
males, but when I got virithin 15 or 20 feet, I saw that the 
birds were copulating. Never before have I seen the sexual 
act performed in anything like the same manner by birds of 
any kind. It lasted at least five minutes . daring which 
the contact was not once broken. Moreover the motions of 
the male were very unlike that of other birds I have seen 
similarly engaged and very like those of certain mammals, 
consisting of a great number of rather slow, deep thrusts 
given, however, with exceeding vigor. Indeed his sexual 
ardor seemed to amount almost to frenzy and to suffer no 
abatement as the minutes passed. The female, meanwhile, 
lay prone on the ground with wings half opened tail 
wide spread, her body heaving and palpitating. The male 
