CATBIRD 335 



the parents of the young. The old birds had taken 91 percent of 

 their food in fruits — buckthorn, catbrier, cherries, raspberries, and 

 blackberries. The nestlings, however, had eaten fruit to the extent 

 of only 4 percent of their food, and the remainder of their diet 

 was principally ants, beetles, caterpillars, spiders, and grasshoppers. 



Dr. I. N. Gabrielson (1913) made detailed observations of the food 

 fed by adult catbirds to their nestlings. Practically all the food 

 delivered consisted of insects, and it was only during the last 2 

 days that food in the form of raspberries and gooseberries was fed 

 to the young. Out of 596 feedings observed there were 99 flies, 55 

 beetles, 52 larvae, 42 mayflies, 40 grasshoppers, 35 moths, 21 meas- 

 uring-worms and 21 worms of various species, 17 spiders, 11 crickets, 

 9 katydids, 8 caterpillars, 8 raspberries, 6 dragonflies, 5 wireworms, 

 3 butterflies, and 1 each of mosquito, small frog, and gooseberry. 

 There were 161 unidentified morsels chiefly insects too small or too 

 crushed to determine with accuracy. Dr. Gabrielson's observations 

 reveal the great variety of insects and the comparatively small 

 amount of fruit that is delivered to the young when insect life is 

 abundant, as it was in the vicinity of the nests he studied. 



If all these varied food habits are considered from a purely eco- 

 nomic standpoint the catbird will be found to have much in its 

 favor to counteract the less than 20 percent of its food that consists 

 of cultivated fruits useful to man. 



Behavior. — ^Although the catbird usually establishes itself in a 

 well-defined territory to which it challenges all intruders, it does 

 at times live in harmony with other birds. E. A. Doolittle (1923) 

 writes of a catbird nest containing four eggs that was built in a little 

 thornbush hardly 3 feet high. Less than 4 feet from the catbird's 

 nest and on the same level was a nest and five eggs of the yellow 

 warbler. Apparently the catbirds made no effort to disturb their 

 smaller neighbors and were indulgent with their presence. 



The catbird is not so adapatable in solving unusual situations with 

 which it may be confronted, as some other birds. Dr. A. A. Allen 

 (1912) found that if a cloth is placed over a phoebe's nest, the bird 

 with a single glance grasped the situation and immediately removed 

 the obstacle. The catbird, however, was at a total loss as to what 

 to do under a similar situation. 



Duriug the first 10 minutes that the cloth was in place upon the nest, the 

 female bird inspected ten times at fairly regular intervals, usually peering 

 from the rear of the side. The first and eighth times, however, she walked 

 around the edge of the nest. After the tenth inspection, an interval of 4 

 minutes ensued before she returned. She then passed around the nest, but 

 inspected its edges more than the rag. The feathers of the nape were usually 

 raised during inspection. After an interval of 1 minute, she approached the 

 nest from the side, crouching and ruffling the feathers as if about to incubate. 

 She then left for 4 minutes. Appearing again, she started to incubate on the 



