FACTORS IN ANIMAL LIFE 



and reared by the sparrow, or the warbler, or the 

 vireo does not sing the song of the foster-parent. 

 Why ? Did its parent not try to teach it ? I have no 

 evidence that young birds sing, except occasionally 

 in a low, tentative kind of way, till they return the 

 following season, and then birds of a feather flock 

 together, robins staying with robins, and cowbirds 

 with cowbirds, each singing the song of its species. 

 The songs of bobolinks differ in different localities, 

 but those of the same locality always sing alike. I 

 once had a caged skylark that imitated the songs 

 of nearly every bird in my neighborhood. 



Mr. Leander S. Keyser, author of " Birds of the 

 Rockies," relates in "Forest and Stream" the re- 

 sults of his experiments with a variety of birds taken 

 from the nest while very young and reared in cap- 

 tivity; among them meadowlarks, red-winged black- 

 birds, brown thrashers, blue jays, wood thrushes, 

 catbirds, flickers, woodpeckers, and several others. 

 Did they receive any parental instruction ? Not a 

 bit of it, and yet at the proper age they flew, perched, 

 called, and sang like their wild fellows — all except 

 the robins and the red-winged blackbirds: these 

 did not sing the songs of their, species, but sang 

 a medley made up of curious imitations of human 

 and other sounds. And the blue jay never learned 

 to sing "the sweet gurgling roulade of the wild 

 jays," though it gave the blue jay call correctly. Mr. 

 Keyser's experiment was interesting and valuable, 

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