Notes on the Plumage of North American Birds 



FIFTY-NINTH PAPER 

 By FRANK M. CHAPMAN 



(See Frontispiece) 



Meadowlark (Sturnella magna). In the Meadowlarks the sexes are much 

 aUke; the nestlings resemble their parents; there is but one molt a year, and 

 seasonal variations in plumage are due chiefly to wear which is exceptionally 

 pronounced in these birds. 



When it leaves the nest a young Meadowlark wears a necklace of black 

 instead of the solid breast-crescent of its parents; it is dull buffy yellow below, 

 its sides practically unstreaked, but the plumage of the upper parts is much like 

 that of the adult and the bird is unmistakably a Meadowlark. 



The first fall (post-juvenal) molt is complete and the young bird then 

 acquires a costume not distinguishable from that of the winter adult. This 

 differs from the summer plumage by its generally browner tone due chiefly to 

 the presence of brownish margins to the body-feathers, the black breast-cres- 

 cent being much obscured by them. 



As the season advances, these margins largely wear off and what remains 

 of them becomes much faded, and the result being the darker, yellower bird of 

 the nesting season. In some instances, particularly in arid regions, at the end 

 of the nesting season, this wearing and fading of the plumage is carried to 

 an extreme which almost obliterates the bird's markings. 



The geographical variations in the color and pattern of the Meadowlark's 

 plumage are as complex as its seasonal variations are simple. From the southern 

 border of its range, in northern Brazil, to its northern limits in Canada, nine 

 different forms are currently recognized, of which four are known from north of 

 Mexico as follows: 



1. Eastern Meadowlark {Sturnella magna magna, Fig. i). The race of the 

 eastern United States.* 



2. Southern Meadowlark {Sturnella magna argutula). A smaller, darker 

 form from the southern states. 



3. Western Meadowlark {Sturnella magna neglecta). The paler form of the 

 western states in which the yellow of the throat extends to the sides of the neck, 

 and the bars on the rump and tail are more clearly defined than in the eastern 

 bird. 



The relationships of the Eastern and Western Meadowlarks have never 

 been satisfactorily determined. In the Mississippi Valley typical examples of 

 each form may be found in the nesting season at the same time — evidence of 

 their specific distinctness in that region, where the few intermediate specimens 

 found may with reason be called hybrids. 



But in the Rio Grande Valley a form {hoopesi) occurs which so obviously 



*The ranges of the several forms are given by Dr. Oberholser in the preceding paper. 



(83) 



