Development and Care of the Young 181 



feeds its young at dusk, or just after dark, and probably again 

 at dawn. Both sexes usually share in bringing food to the nest, 

 but this rule is by no means universal. 



The young require animal food during the early days of life, 

 and in the interior of the country this consists mainly of insects in 

 the larval or mature stages, spiders, earthworms (at least in the 

 Robin), and possibly slugs. Even snakes and frogs, to which 

 Hawks and other birds of prey devote much attention, no doubt 

 at times fall a prey to smaller adversaries. In the hills above 

 Lucerne, Switzerland, on the tenth of July I once surprised a 

 Thrush (Merula atra) hammering at a small snake. The ani- 

 mal, when whole, measured only seven inches in length, and 

 this bird had already cut off two inches of its tail, which was 

 possibly intended for its young. Aside from the habits of the 

 adult, the nature of the food brought depends much upon the 

 character of the supply. If food is plenty a wide choice is 

 possible, but at the pinch of hard times every rule is broken 

 and nothing is refused. When the Kingfisher finds crayfish 

 abundant they are carried to the nest, and this species has also 

 been known to go to the fields for insects. Along the coast 

 various other invertebrates undoubtedly contribute to the food 

 supply of both young and adult birds of many species. Birds 

 which never taste of fruit themselves naturally do not give it 

 to their young, while Robins, Orioles, Vireos, and Waxwings, to 

 mention but a few of the berry -pickers, vary the diet of their 

 fledglings with a liberal supply of fruits of various kinds. 



The food is placed not simply in the mouth of the young but 

 well down into the sensitive throat, and if the bird does not 

 immediately respond, it is withdrawn and passed to another, 

 and often to a third, until a throat is found which has the proper 

 reaction time. If the gullet is already full, the swallowing 

 reflex is inhibited, and the bird must wait. If the experiment 

 of feeding a young bird like a Robin at the nes.t is tried, it will 

 be found that the food passes slowly down the oesophagus, and 

 when this is filled no more can be taken until the channel is clear. 

 The gullet thus acts as a brake to the tendency of the greedy 

 young bird to gorge itself to suffocation. Cedar-birds, however, 



