THE MISSISSIPPI RESERVES 305 



royal terns flew off at our approach, the hesitat- 

 ing advent of the returning parents was always 

 accompanied by the presence of a few gulls. 

 Commonly the birds lit a few yards away from 

 the eggs, on the opposite side from the observer, 

 and then by degrees moved forward among the 

 temporarily forsaken eggs. The gulls were 

 usually among the foremost ranks, and each, 

 as it walked or ran to and fro, would now and 

 then break or carry off an egg; yet I never 

 saw a tern interfere or seem either alarmed or 

 angered. These big terns are swifter and better 

 fliers than the gulls, and the depredations take 

 place all the time before their eyes. Yet they 

 pay no attention that I could discern to the 

 depredation. Compare this with the conduct 

 of king-birds to those other egg-robbers, the 

 crows. Imagine a king-bird, or, for that matter, 

 a mocking-bird or thrasher, submitting with 

 weak good humor to such treatment! If these 

 big terns had even a fraction of the intelligence 

 and spirit of king-birds, no gull would venture 

 within a half-mile of their nesting-grounds. 



It is one of the innumerable puzzles of biol- 

 ogy that the number of eggs a bird lays seems 

 to have such small influence on the abundance 

 of the species. A royal tern lays one egg, rarely 

 two; a gull three; a skimmer four to six. The 



