222 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



Spring. — North of Florida this species is only a summer resident, 

 the northward migration starting in Florida about the 1st of May. 

 It is rather a late breeder. Even on the Gulf coast egg laying does 

 not begin until the last of May, and farther north it is two or three 

 weeks later. 



Nesting. — The only breeding colony of this species that I have ever 

 seen was on Grand Cochere Island, in the Breton Island reservation. 

 This was a low, flat sandy island, hardly more than a sand bar, 114 

 miles offshore, south of Pass Christian, Mississippi. I have given 

 a fuller description of it under the royal tern. When I visited this 

 island on June 18 and 19, 1910, 1 estimated that its bird population 

 consisted of about 7,000 royal terns, 2,000 Cabot's terns, 600 black 

 skimmers, 80 Caspian terns, and 20 laughing gulls. These estimates 

 were arrived at by counting the nests in a measured area and then 

 roughly measuring the total area occupied by the polonies. 



There were several small mixed colonies of royal and Cabot's 

 terns, but the bulk of the population was concentrated in one vast 

 colony of approximately 3,500 nests. In this and in the smaller 

 colonies the Cabot's terns were grouped together in certain sections 

 by themselves, though not in any way separated from the general 

 continuity of the colony; but their nests were seldom, if ever, scat- 

 tered singly among the royal terns. The nests of both species were 

 evenly spread out over a level, sandy plain, above the ordinary high- 

 tide mark, in the central portion of the island, which was entirely 

 devoid «of vegetation — a hot, dry waste of sand. They were appar- 

 ently placed at measured distances, just far enough apart for each 

 sitting bird to be beyond the reach of its neighbor ; probably the dis- 

 tances were actually measured by the birds when the eggs were laid, 

 each bird choosing a spot as close to its neighbor as seemed safe from 

 the jabs of a long, sharp bill. The nests were hardly worthy of the 

 name, for they were never more than slight hollows in the sand, with 

 no attempt at lining whatever, and often the eggs seemed to have 

 been dropped on the smooth, flat sand without even a pretense at a 

 hollow. Nearly all of the nests held one egg each, but a few held 

 two. This colony had been washed off another island earlier in the 

 season and had come here for a second attempt at nesting. Captain 

 Sprinkle told me that both of these terns usually lay two eggs at the 

 first laying and only one at the second. The Cabot's terns in this 

 colony were very tame, even tamer than the royal terns. After they 

 became accustomed to my presence I had no difficulty in photograph- 

 ing them at short range without the use of a blind. I was disap- 

 pointed to find no young in the colony, which would have given me 

 an opportunity to study their home life even better. 



From what I can learn from the writings of others this colony 

 was fairly typical of the species and descriptions of other breeding 



