180 NEW YORK ZOOLOGICAL SOCIETY. 



of the status of the avifauna of Cobb Island, showed the diminu- 

 tion in numbers from the figures given by Mr. Chapman and other 

 observers in 1902 and in former years. This emphasized the im- 

 portance which absolute protection would mean, not only to the 

 breeding birds in summer, but also to the great numbers of birds 

 which make these waters their home during fall and winter.* 



D. The most important result of our visit to Cobb Island was 

 a discovery of far-reaching importance to the bird collections 

 of the Zoological Society. A score or more of the eggs of terns, 

 skimmers and gulls, nearly ready to hatch, were collected and 

 brought to the Zoological Park, with the intention of preserving 

 the embryos for future microscopical and gross study. When 

 the time came to remove them, although the eggs had been gath- 

 ered over three days previously, and indeed some were partly 

 crushed on the journey, yet the little unhatched creatures were 

 found to be in such vigorous condition that instead of being sac- 

 rificed to the science of embryology, the eggs were placed in an in- 

 cubator. Not only did the individuals of each species hatch and 

 escape from the shells, but they were successfully fed and reared 

 by hand until the young birds were able to feed themselves. This 

 unique undertaking has yielded many interesting facts as to the 

 growth and development — both physical and mental — of these 

 little-studied young birds. These notes will be elaborated during 

 the coming year, and will fill out many important gaps in the life- 

 histories of the birds. For example, the characteristic call and 

 alarm notes or the adult terns and skimmers are uttered by the 

 young birds while their bodies are yet within the egg. The food 

 of the terns for more than a week is fish which has been macer- 

 ated in the crop of the parent for about two hours, while the 

 young skimmers require small living fish from the first. The nest- 

 lings of the black skimmer have only about one-half the strength 

 of young common terns, and about one-third that of nestling gulls, 

 the comparison, of course, being between birds of the same age. 

 This would seem to lend credence to the report that the young 

 skimmers hatched on Cobb Island this season have succumbed 

 to the attacks of the ghost-crabs. 



The fact that birds so small and so fastidious as to diet were 

 successfully reared, presages important results when the eggs of 

 birds of other orders can be collected and incubated. Young birds 



* As an appendix to this article I have added a list of some of the more striking 

 birds which other observers have noticed on or near Cobb Island, taken mostly 

 from Dr. Rives' " Catalogue of the Birds of the Virginias." 



