EIGHTH ANNUAL REPORT. 177 



scramble away, but his strength failed him, and as the fierce ants 

 had already pierced his thin skin, there is little doubt as to what 

 the ultimate result would have been. I removed the blood-stained 

 egg, scattered the ant hordes and placed the nestling Tern some 

 distance away. Is not the principal result gained by the removal 

 of the blood-scented shell to lessen the danger of attacks from 

 keen-scented enemies — insects and others, — rather than to bridge 

 over any fancied weakening of the protective coloration scheme 

 which the unbroken egg and the young bird so perfectly typify ? 

 And when we consider what a great source of danger the diffu- 

 sion of the odor even of the rapidly drying blood within the 

 shell would be, does this explanation not suffice to account for 

 this habit of ground-nesting birds, and do away with the need 

 to trace its origin to ancestral species which carried on their nidi- 

 fication in trees? We were surprised to notice the extent to 

 which the Terns and Gulls feed on insects, this diet in some cases 

 seeming to take entirely the place of fish. 



21. Forster's Tern (Sterna forsteri, Nutt.). 



22. Gull-Billed Tern (Gelochelidon nilotica, Hasselq.). — About 

 a score of these birds nest upon the island, their habits being very 

 similar to those of the Common Terns. 



23. Laughing Gull (Larus atricilla, Linn.). — We estimated 

 that there were five hundred Laughing Gulls on the island, nest- 

 ing among the clumps of grass in two large colonies. These were 

 associated with the colonies of skimmers and terns, the several 

 species evidently finding each other's presence agreeable, and 

 thus enlivening the island at these favorite sections from the beach 

 back through the dunes and marsh. The nests of the Guls were in 

 some instances very artistic, the eggs being concealed under over- 

 hanging grass stems, with an arched entrance, two feet or more 

 in length. When the nests are built on the lower, wet portions of 

 the marsh, they are often a foot or more above the ground, the 

 eggs lying on a rough pile of reeds. 



These Gulls are strikingly colored, their wings and back being 

 pearl-gray, the large flight feathers black, the under parts white, 

 while the head and throat is a dark slate in hue. Mr. Chapman has 

 very aptly compared them, when sitting on their nests, to white 

 flowers scattered over the marsh, and even when we know that 

 they are birds, the odd coloring of the head and wing feathers, 

 rendering these parts almost invisible, so breaks up the shape of 

 the sitting bird that the general effect is only of an indeterminate 

 mass of white. 



The Laughing Gulls do not swoop at one as do the terns and 



