SCOTT'S RUFOUS--CROWNED SPARROW 925 



ti\aty SO the birds are less inconspicuous. He "noted the birds as 

 beginning to sing and mate [i.e., pair?] as early as the middle of 

 March," which made him think (mistakenly?) that "The species 

 raises three broods at this point, and * * * the breeding season 

 extends over a period of five months." While this seems unlikely, 

 detailed observations of what rufous-crowned sparrows actually do in 

 late March, April, and May of both normal and wet years are still 

 lacking and most urgently needed. 



Nesting season. — In Arizona during normal, dry springs the first 

 eggs are laid about the end of May or in early June, In the Huachuca 

 Mountains F. C. Willard (1912b) found eggs ^\4th "incubation ad- 

 vanced" May 24, 1907, and "newly hatched young May 25," which 

 he considered exceptional. Unfortunately he failed to specify the 

 year in the latter case. He states that "fresh eggs may be looked for 

 after May 20," with the first week of June being the "height of the 

 nesting season." Later he (WiUard, 1913) found them "nesting 

 regularly dm-ing August" 1913, having taken his last set of "nearly 

 fresh" eggs on August 15. 



My own observations agree wth the above to a great extent. 

 Thus, I have heard singing east of Tucson as early as Mar. 18, 1939, 

 and the abundance of young in early fall shows that the JiUy and 

 August nests reported by W. E. D. Scott and F. C. Willard were 

 perfectly normal. In fact Seymoiu- H. Levy (MS.) found birds in- 

 cubating eggs (two and three, respectively) near Arivaca, southern 

 Pima County, on Sept. 5, 1960. Farther south, in Nayarit, Mexico, 

 I have taken young (of a darker race) stUl not fully grown (tail 46.8 

 millimeters) on Oct, 24, 1957; and in Oaxaca (grown, but not far 

 into the postjuvenal or first prebasic molt) on Nov. 23, 1958. 



In wet years in Arizona, the story is different. Thus it is un- 

 fortunate that Scott did not give further details on w^hy he thought 

 breeding commenced in mid-March; for my wet year studies yield 

 dates exactly between this period and F. C. Willard's. While agreeing 

 -with Willard that even newly hatched young are unusual on May 25, 

 nevertheless I took full-gro\vn young May 26, 1952 in the Santa 

 Catalina Mountains — a young male from each of two different 

 families which differed in the amount and heaviness of streaking. 

 Both showed some apparent first-basic plumage beside the lower back; 

 probably this area produces no juvenal plumage, for neither was 

 molting there. Both had pin feathers on the breast and in different 

 parts of the upper surface ; one also had some on the legs but was not in 

 obvious first prebasic molt. The other had begun this molt, and its 

 testes were already 1^ by 1 millimeters. 



The 1958 rains had much less effect in the same place; my com- 

 panions and I found no young on May 25 and only one family on 



