10 EXPEDITION TO LAYSAN ISLAND IN 1911. 



exact dates but thinks the first were imported eight or nine years 

 ago, or about 1903. The rabbits have crossed and produced some 

 strange-looking animals, both in form and color. We dressed some 

 of them for food and found the skins as tough and thick as that of the 

 groundhog. 



Rabbits have killed many bushes, but have not caused so great 

 devastation as one would expect from their numbers. In the latter 

 part of the afternoon they may be seen feeding. They are very fond 

 of the green j uncus that grows near the lagoon, and, while they are 

 eating, their bodies are concealed among the thick growth and only 

 their ears show. At times there are so many ears protruding that 

 they resemble a vegetable garden. 



It would be very difficult to exterminate these animals without 

 harming the birds. They live everywhere; even in the large tern 

 rookeries we saw many of them. They have made burrows of their 

 own and also, when pursued, take refuge in the numerous petrel 

 burrows. It is impossible to drive or snare them, as there are plenty 

 of holes in which they can find shelter. Poisoning the rabbits would 

 be disastrous to certain species of birds and indiscriminate shooting 

 would also be harmful. It is my opinion that a well-organized party 

 with small repeating rifles, say 22 caliber, could entirely exterminate 

 these pests. This should be done in the season when it would inter- 

 fere least with the nesting birds. 



The man-o'-war birds catch them. Several times We saw them 

 pick up full-grown rabbits, and we found young ones dead on the 

 nest of the red-footed booby. 



GUINEA PIGS. 



Guinea pigs were found on the south end of the island in the thick 

 j uncus. They were rather abundant in this one place, seven being 

 seen at one time, but they have done no harm. Mr. Schlemmer 

 introduced these animals. 



INSECT PESTS. 



The collector is not without his troubles on Laysan. Never have 

 I seen so many flies in one small area. Our laboratory was so full of 

 them that we were obliged to suspend work to reduce their numbers. 

 Shallow pans of formalin, about 2 per cent, did wonders in this 

 direction. Not only did the flies annoy us as we worked but they 

 would blow our bird skins, and even after the latter were thoroughly 

 dry and cured, we often found fresh masses of eggs deposited on the 

 feathers. The feet of the larger birds would be eaten by larvae if 

 they were not thoroughly poisoned. 



In addition to the flies there were small ants which ate and destroyed 

 the feathers of the smaller specimens. There were also several 



