The Terns of Weepecket Islands 15 



call-note, varied somewhat as the bird sallies at the intruder's 

 head. While incubating, especially during the minutes imme- 

 diately following their return to the nests, the birds cackle 

 for all the world like a hen announcing the arrival of an egg", 

 until at times the island sounded like a prosperous poultry 

 farm. This cackling is varied occasionally by . a " chip," 

 which when first heard calls instantly to mind the song spar- 

 row, but is of rather rare occurrence. When quietly incu- 

 bating, often a neighbor will approach too closely, or some 

 overhead bird will fly too low, whereupon the bird raises its 

 head and utters a squawk not unlike that of the little green 

 heron. Another note, and one that seems to be given at 

 almost any time the bird is on the ground, is comparable to 

 that made by a mallard "rinsing'' its mouth. This was heard 

 a number of times while the birds stood over the eggs prior 

 to sitting upon them, a sort of chattering, as it were. As a 

 whole, the ventriloquial powers of the tern were a big surprise, 

 and I was kept busy jumping from one peep hole to another 

 in order to find out which bird was performing the particular 

 notes I desired to locate. 



At four o'clock, the sun being no longer suited for photo- 

 graphic purposes, I left the blind, and wandered about the 

 island with the idea of estimating the number of nests, and 

 thereby getting at some idea as to the number of birds using 

 the island. It was out of the question to count the nests, both 

 because of the great numbers, and because of the fact that 

 they were scattered over the entire island, not only on the 

 beaches, but through the poison ivy sections, where I did not 

 care to follow. If possible, the nests were more abundant in 

 the vegetation than on the open sand beaches : but whether 

 in the grass or on the beach, it was always a difficult task to 

 walk without stepping upon a nest full of eggs. By counting 

 the number of nests in different places, averaging them, and 

 estimating the ratio of the areas counted to the entire island, 

 a rough estimate was secured as to the number of nests on 

 the island. I conclude from this estimate that there were 

 probably not fewer than two thousand nests, thus accounting 

 for about four thousand birds. 



