302 Bird -Lore 



for its food-call will carry as far as it could possibly have flown since its 

 previous feeding. 



The syrinx of a young bird, and therefore its song, does not develop fully, 

 ordinarily, until the winter or following spring, though I believe there are 

 instances of domesticated song-birds singing the same year they are hatched. 

 It is not the case with wild birds, however, though some of the shaky voices 

 that we hear in the fall may possibly be from early hatched birds. 



The time required for the young bird to acquire its full plumage varies with 

 different species. Ordinarily, by the time the wing-feathers are full grown, the 

 body feathers of the juvenal plumage begin to drop out and the first winter 

 feathers come in. If the male and female are alike, this plumage, which is 

 usually fully acquired by September, will be almost indistinguishable from 

 that of the adults, but, in brightly colored birds where the male and female are 

 different, it will resemble the female or the male in winter plumage. The 

 next spring it will have a complete or a partial moult of its body feathers to 

 bring it into its breeding dress just as in the adult. Immature Scarlet Tanagers, 

 Goldfinches and Indigo birds then closely resemble the adults, being only 

 slightly less brilliant. With some of the Warblers, however, like the Redstart 

 and Myrtle, there is but a slight moult and the immature male still resembles 

 the female with a few of the male feathers. This often results in the recording 

 of female birds singing. Some birds seem to require even more than the two 

 years to acquire the full brilliancy of plumage, but ordinarily, after the second 

 year, the health of the bird will affect its plumage more than its age. — A. A. A. 



QUESTIONS 



i. What is meant by altricial young and what groups of birds have altricial young? 



2. What is meant by precocial young and what groups of birds have precocial young? 



3. Describe the covering of as many young birds as you have observed. 



4. How do young Cuckoos, Kingfishers, and Chimney Swifts differ from other altricial 

 young? 



5. How long does it take for young birds to acquire their juvenal plumage? Have you 

 ever made any observations of your own upon the time spent in the nest by young birds? 



6. What is meant by regurgitation? How long are young birds fed this way? 



7. Describe other methods of feeding the young employed by birds? 



8. What prevents young birds from being overfed? 



9. How much food do young birds require? Have you ever made any observations of 

 your own upon the number of times a nest full of young birds are fed? 



1 o. How long are young birds brooded and what is the purpose of brooding? 



11. In what ways do birds express their attachment for their young? 



12. When does the fear of man develop in young birds? 



13. What would you do with a young bird if you found it apparently without parents? 



14. How long does it take for young birds to acquire their full plumage? 



