178 U.S. NATIONAL MUSEUM BULLETIN 237 part i 



A. A. Forbes (1882), in a study of the relations of birds to an orchard 

 infested with cankerworms, found that 10 out of 11 dickcissels collected 

 had eaten cankerworms, which made up 43 percent of the food eaten 

 by the entire group. Lepidoptera as a whole composed two-thirds of 

 the food. Butler (1898) states that caterpillars are eaten in May in 

 the ratio of about 20 percent, while they make up 70 percent of the 

 food of birds collected during cankerworm infestations. 



The stomach contents are clearly in the dickcissel's favor. Though 

 32 percent of the food of the Illinois specimens was grain, this was 

 counterbalanced by the 36 percent weed seeds and 32 percent insects, 

 mostly destructive grasshoppers. As the stomachs were taken after 

 the oats and wheat had been removed from the fields for threshing, 

 probably all the grain they contained was waste. The grain I have 

 seen dickcissels eat in the fields before harvest time was chiefly from 

 heads or panicles lying on the ground, which the binder cannot gather 

 and therefore can be classed as waste. 



The analyses of stomach contents reveal much of interest regarding 

 the food of the dickcissel, but daily observations at the nests when the 

 young are being fed supply even better evidence in the case of the 

 dickcissel versus man. Not until we observe its feeding habits during 

 the nesting season does the dickcissel receive the full credit it deserves 

 as a destroyer of insects, especially grasshoppers. Judd (1900) found 

 that 14 stomachs of nestlings contained chiefly grasshoppers and 

 crickets. Regarding adults Judd (1901) states that stomachs coUected 

 in summer contained more crickets and grasshoppers than those of any 

 other bird whose food habits the Biological Survey investigated. 



The first food given the newly hatched dickcissels in Illinois were 

 small green lepidopterous larvae and soft-bodied winged insects. 

 Though the adult birds delivered scores of these larvae and insects, 

 their stomachs contained very few. One female made regular trips 

 every few minutes to an elm tree for bright green caterpillars 2 or 3 

 centimeters long (species undetermined). These caterpillars consti- 

 tuted probably 90 percent of the young birds' food during their first 2 

 days of life. As the female averaged 10 trips an hour, she destroyed 

 more than 100 larvae daily. On the third and fourth days she added 

 other insects to the diet of the young: aphids, a few unidentified 

 winged insects, and a considerable number of small grasshopper 

 nymphs. With these additions the number of caterpillars decreased 

 correspondingly. 



From the fifth day until the young left the nest 4 days later, their 

 food was practically all grasshopper nymphs and adults garnered 

 from a nearby clover field they were overrunning, stripping the clover 

 stems and leaves. During the fledgling's last days in the nest, 

 grasshoppers were delivered at the rate of one every 3 or 4 minutes. 



