° 1920 J Chapman, Proposed New Race of the Killdeer. 107 



margined with rusty, but never, so far as my observations go, to 

 the extent shown by the Peruvian bird. Some comparable North 

 American birds, on the other hand, show almost no trace of this 

 rusty margining, and, representing the extreme of difference 

 between peruvianas and vociferus vociferus, may perhaps indicate 

 the type of coloration toward which the latter is diverging. That 

 this divergence is of comparatively recent occurrence in the life 

 of the species, is suggested by the inconstance of the features which 

 characterize it, and also by the fact that in juvenal plumage the 

 Peruvian and North American forms are alike. 



The West Indian form appears to differ from true vociferus only 

 in size, and consequently, is not intermediate in color between 

 it and peruvianus. 



As stated above, two downy young but a few days from the egg, 

 were taken at Paletillas, June 22, and we may accept these birds, 

 in connection with the seven adults from the Paletillas region which 

 are completing their post-nuptial molt, as conclusive evidence 

 that the Peruvian Killdeer nests in May and June. But examina- 

 tion of the Bequeta specimens shows that May and June by no 

 means constitute the entire nesting season of the Killdeer in Peru. 



Four of the Bequeta specimens, taken January 23 and 24, are 

 adults in the midst of the post-nuptial molt in which wings and 

 tail as well as body feathers, are being renewed. The remaining 

 feathers of the nuptial plumage are much worn and practically 

 without rusty margins; the incoming new plumage is margined with 

 rusty. 



The fifth Bequeta specimen, taken January 22, is in fresh juvenal 

 plumage with portions of the natal down still adhering to the ends 

 of the central rectrices and longer upper tail-coverts. Our col- 

 lection contains specimens which show that in the Killdeer frag- 

 ments of the natal down may remain at the end of the central 

 retrices until the spring following the bird's birth — a surprising 

 fact — but the general condition of the plumage of this Bequeta 

 bird with its fresh, narrowly margined dorsal plumage, shows that 

 it is a comparatively young bird, exactly similar, indeed, to August 

 specimens of vociferus vociferus from various parts of the United 

 States. Consequently, just as the Piura birds prove that in north- 

 western Peru the Killdeer breeds in May and June, so the Bequeta 



