BREEDING PLACES OF SEA BIRDS. 169 



We soon discovered this to be due to the fact that two boat loads of 

 Moro egg-hunters had on the previous afternoon removed every egg 

 from the ground nests. Their boats were still anchored on the shoal to 

 the north of the island and were found to contain both boobies' eggs and 

 sea turtles' eggs in large numbers. 



Apparently they had been too lazy to climb the trees after the eggs of 

 the red-legged boobies, some of which we were, therefore, able to collect. 



The Moros assured us that by noon there would be plenty of fresh eggs 

 in the nests of the brown boobies, and this proved to be the case. The 

 boobies of both species were so tame that we experienced no diiSculty in 

 catching alive as many as we needed for specimens, and we were also able 

 to secure a very interesting series of photographs, and to observe closely 

 the nesting habits of the birds of both species. The male and female 

 brown boobies were readily distinguished by the fact that the former had 

 the bare skin at the base of the bill and on the throat dark blue, while 

 in the latter it was bright lemon yellow. 



The gi-ound nests of the brown boobies were made of bits of rotten 

 wood, dead leaves, small branches, and twigs to many of which green 

 leaves were still attached. In fact we saw the birds breaking such twigs 

 from the trees. The female usually remained sitting bolt upright in 

 her nest, while the male brought nesting materials which he turned over 

 to her. These she promptly put in place, not infrequently lifting and 

 putting dovra. repeatedly a given leaf, twig or bit of punlvy wood until she 

 had placed it just to suit her. Occasionally the materials brought by 

 male birds were rejected, and as a rule when the latter endeavored to put 

 any material in place in the nest, as was sometimes the case, it was 

 thrown out by the females, which were evidently determined to construct 

 their houses in strict accordance with their own ideas and to keep the 

 male birds under proper discipline. 



In many cases the nests were in close proximity to each other and the 

 male birds were constantly tiying to steal materials from other nests. 

 This led to vigorous vocal protest from the rightful owners and not 

 infrequently to rough-and-tumble fights as well. The fights were all 

 of short duration and quite bloodless. In no instance could we see that 

 one booby really injured another. 



The red-legged boobies not only stole nesting materials from their 

 brown relatives, but quarreled shamefully among themselves. 



JEvery bird which attempted to fiy through the air with a fairly size- 

 able branch in its mouth was set upon by half a dozen others, which, in 

 their efforts to make it drop its burden frequently drove it to the ground 

 where it was vigorously mauled until it relaxed its hold upon the branch. 

 Some other bird then attempted to fly off with it and was set upon in 

 turn. These contests seemed always to end when a lucliy individual 

 succeeded in getting to its nest with the coveted branch. 



