BIRDS, CATERPILLARS, AND PLANT LICE. 137 



caterpillars from the web and ate them. There were two Crows in the 

 brown-tail moth tree when I came in sight of it. I saw one of them 

 peck twice at the branch, and swallow something. In attempting to get 

 nearer to them I made a noise, and frightened them away. Could find 

 nothing on the branch they were on except brown-tail moths, which 

 they were eating. The next visitor was an Oriole, who came to the 

 tree and ate thirty-four larvse in six minutes, then flew away. He 

 hammered each larva once or twice before swallowing it. The next 

 visitor was a Wilson's Thrush. He first perched on a small oak on the 

 top of the ledge, then hopped to the dry leaves, and seemed to be 

 searching among them for food for about five minutes. Then he flew 

 to the tree and took a larva while in sight and swallowed it. He 

 probably took more while in the tree. He was in the tree four minutes. 

 He then flew down and began searching in the grass. A Red-eyed 

 Vireo perched in the oaks and searched for about nine minutes. I saw 

 him take over fifty larvte of various kinds from the leaves, some of 

 which were leaf- rollers. I could see him picking insects from the under 

 sides of the leaves. To accomplish this he would grasp the petiole with 

 his feet, and hang, back down, and pick the larvse off. He then went 

 to the apple tree and took twenty -nine larvae (brown-tail) before flying 

 across the boulevard. He was in the apple tree about six minutes. He 

 beat nearly every one on the branch before eating it. 



From this and later experiences it seems that many birds 

 have learned to eat the larvae of the brown-tail moth even 

 when the caterpillars reach an age when the detachable hairs 

 are dangerous. Probably by shaking off these hairs the birds 

 render the larvae eatable, and even fit to feed to their young. 



MAY 25. A Golden-winged Warbler came to the oak trees next 

 the boulevard, and sang for nearly five minutes in a low, wiry voice. 

 He then began searching for food. Frequently I would see him take 

 some small green larvae from the leaves, but could not tell what kind 

 it was. He then flew to the apple tree and picked eleven brown-tail 

 larvae from the leaves and swallowed them, after hammering them on 

 the limbs. He probably took more while feeding in the tree, about 

 eight minutes. He then flew over the ledge. A pair of Orioles were 

 back and forth over the ledge, and would occasionally stop and eat the 

 brown-tail larvae for a moment or two, but did not make a long stay 

 while I was there. They had probably got their fill earlier in the clay. 

 An Indigo Bird lit in the top of one of the oak trees for a moment, then 

 flew to the apple tree and ate six of the brown-tail larvae, and was then 

 chased out by the P^nglish Sparrows. Three of the Sparrows perched 

 in the tree and picked off two or three brown-tail larvse apiece, then 

 flew to the boulevard. A pair of Scarlet Tanagers perched for about 



