RUFOUS-WINGED SPARROW 915 



old, and the longer ones are more or less worn and frayed. Curiously 

 the secondaries, longest tertial, and innermost two primaries are all 

 new in the right wing, though old in the left. Molt of the greater and 

 especially middle wing coverts is also markedly asymmetrical. 



Most of the few specimens taken in years of atypical nestings 

 point to a partial or complete suppression of the prealternate (pre- 

 nuptial) molt by the developing ecological conditions that ultimately 

 induced nesting. Thus parents of small young taken in swale habitat 

 on May 20, 1952 (adults, male and female, of different famihes) and 

 June 21, 1952 (first-year female) are not molting and have not re- 

 placed many feathers. The male has lost several fliglit feathers, 

 chiefly secondaries, but shows few new feathers (inner right scapulars; 

 left central and next-to-central tail feathers). The females are even 

 more worn, but the first-year one has started to molt on the breast, 

 lower chest, and back. On the other hand, an adult male of the 

 same date (June 21), but whose nest had fresh eggs, has molted almost 

 normally, is largely m fresh feather, and still shows some molt, mostly 

 on the breast and lower chest. 



In the deep-soil habitat no early nestings were observed. In 

 the most advanced nesting noted, an adult female was carrying grass- 

 hoppers to young on July 13, 1952; she had molted parts of the wing 

 coverts, most of the forecrown, back, and chest, and some remiges in 

 the right ^\ing (tertials and innermost primary) ; she also had some new 

 feathers in the rump, and perhaps elsewhere, but she retained the old 

 nape, upper and under tail coverts, rectrices (except the outer pair), 

 flanks, sides of the neck, and part or all of the throat, malar area, and 

 lores. An adult male was seemingly in an earUer part of the breeding 

 cycle; he was singing near a nest containing an egg shell. Some molt 

 was still in progress, and he retained some old plumage, including the 

 greater wing coverts and part of the crissum; but the prealternate 

 molt was nearly complete. In fact, even the two innermost pairs 

 of primaries had been replaced. Thus molt in this population had 

 been less aflected by the unusual weather and ecological conditions. 



Aside from the scanty data provided by Fi'ank A. Pitelka (1951), 

 no information is available which would suggest whether or not 

 rainfall also affects the timing and extent of the molts of the more 

 southern races in Mexico. 



Food. — Field observations show that during the nesting season 

 a good deal of the food consists of small green caterpillars of the 

 inchworm type. Other blackish caterpillars and small grasshoppers 

 7 to 10 millimeters long are also taken. The adults feed largely 

 in the desert hackberry bushes at this tune. EarUer in the summer 

 the birds catch low-flying insects in short sallies while on the wing and 

 glean others from the stems of small plants such as burroweed, 



