116 USEFUL BIRDS. 
fact has not been previously noticed. It will be seen at 
once, by one who makes a study of the subject, that the 
error which has been so long persisted in arises, first, froma 
lack of careful observation. It is noteworthy that most of 
the more observing writers give the Cuckoo as an exception 
to their established (?) rule that birds do not eat hairy cat- 
erpillars. It is not strange that the Cuckoos should have 
been known for years to feed on such caterpillars. The 
Cuckoos are sizable birds; they are not very shy, and, .as 
they feed on the larger caterpillars when those insects are 
full-grown, and as both Cuckoos and caterpillars are common 
in the vicinity of dwellings, their habits in this respect could 
not escape the most casual observer. But it is much more 
difficult to observe the habits of shy birds, such as the Crows 
and Jays, which feed on the larger caterpillars; and to learn 
the feeding habits of the smaller birds, which feed mainly 
on the minute larve soon after these have hatched from 
the egg, requires the most painstaking care. Most of the. 
caterpillars that are eaten by the smaller birds are taken’ 
when the larve are so small and have done so little injury 
that they have not become apparent to common observa- 
tion. Thus they are destroyed before most people even 
suspect their presence ; while, per contra, those which escape 
the smaller birds and grow to a large size are seldom eaten 
in this stage except by a few species of the larger birds, 
which, like the Cuckoo, Catbird, Jay, and Crow, bolt them 
whole. Thus another source of the prevalent opinion is ex- 
plained. A few smaller birds, such as the Titmice, Vireos, 
and Orioles, tear caterpillars open, and thus avoid swallowing 
the head, skin, and hair. Sométimes, when the adult birds 
put such caterpillars down the throats of their well-grown 
young, the little birds will reject them. A young Oriole put 
its foot upon the protruding end of a larva, and pulled the 
wriggling creature back to daylight. There is no doubt 
that when these caterpillars grow large many small birds 
experience the same difficulty in eating them whole that we 
should encounter were we attempting to swallow the bones of 
a fish. So, when larve have grown large, and are covered 
with stiff spines or hairs, only the larger birds or the most 
