LIFE HISTORIES OF NORTH AMERICAN GULLS AND TERNS. 223 



colonies, all of which seem to be on low sandy islands on the sea- 

 coast, would be useless repetitions. On the other side of the At- 

 lantic, however, the nesting habits of the species may differ, as 

 several writers speak of nests among the beach grass and nests lined 

 with dry grass. References to such nesting habits by American 

 writers are probably based on the statements of foreign writers. 



Mr. W. E. D. Scott (1888) took some young birds on September 

 20, 1886, " not quite fully grown, indicating that probably more 

 than one brood is raised, and showing how late in the summer the 

 last broods are hatched out." If this species raises two broods it is 

 a notable exception to the rule among the terns ; probably Mr. Scott's 

 birds were hatched out late in the season, because earlier attempts 

 were frustrated by storms or other destructive agencies. Cabot's 

 tern has been said to lay as many as three or four eggs to a set,: but 

 I believe that such large numbers are exceedingly rare, on this side 

 of the Atlantic at least. Two eggs seem to be the normal number, 

 with occasionally three. One egg to a nest is the rule on second and 

 subsequent layings. 



Mr. Stanley 0. Arthur writes me regarding his observations on 

 this species : 



There was very little opportunity given me at this time to study the Cabot 

 tern and its young, as what little ones were there were absolutely in the 

 downy stage and evidently too young to eat, for at no time did I see a young 

 Cabot being fed by its parent. I did, however, see the male (?) bringing the 

 female (?) fish food while she was engaged in incubating a single speckled 

 egg which she covered. Here I had an excellent opportunity to learn that the 

 Cabot tern incubated but one egg. While it is true that in one or two instances 

 there were two eggs, so close to make it appear they belonged to a single 

 clutch, yet when the mother bird settled on them she threw her breast feathers 

 over one egg, to the other paying not the slightest concern. In fact, at one 

 time I saw a Cabot tern cover a single egg and with her bill roll the other 

 some inches away from the hollow in which she had deposited her own. 



At this time I made an experiment, contemplated for the past several years. 

 I had often wondered why it is, where there are several thousand single 

 speckled eggs, such as the Cabot terns deposit on the beaches, one particular 

 egg can be singled out by the parent as her own private and individual; 

 property, and have often wondered whether or not they can, with certainty, 

 know their own egg. I have often been asked.: "How does the tern know' 

 its own eggs?" and have always facetiously answered: "By counting the 

 spots." As I was studying the birds I selected two Cabots, one on the left 

 and the other on my right, that were marked quite distinctly— one having a 

 wholly black crest and one having its crest speckled with a few white feathers 

 which heralded the coming of the winter plumage. 



At 11.15 I left the blind, which naturally scared off the birds, and changed 

 the egg on my left, which had been covered by the pure black-headed tern, 

 and moved it several feet away, exchanging it for the egg that had been 

 covered by the Cabot with white feathers in its crest. This egg was placed 

 on the spot belonging to the black-headed tern. At 11.18 the circling and 

 frantically crying birds commenced resettling on their eggs, and showing not 



