614 BIRDS OF THE REPUBLIC OF PANAMA PART 4 



201-202) noted that in Costa Rica it sings from January to August, but 

 most vigorously in February and July. This is correlated with the birds' 

 two-part nesting season: in Costa Rica breeding takes place between 

 February and May or June and again in July or August. Wolf (Con- 

 dor, 1969, pp. 212-219) found that in Costa Rica the annual molt took 

 place between the two breeding periods and there was a partial pre- 

 nuptial molt prior to spring reproduction. 



Blake (Fieldiana: Zool., vol. 36, no. 51, 1958, p. 575) noted that at 

 Volcan de Chiriqui breeding peaks were in May and August, and he 

 reports juveniles in the Monniche collection taken from March 19 to 

 October 10. The earliest juvenile I collected was on February 9, 1960, 

 at El Volcan. A nest in the Monniche collection was found on Febru- 

 ary 23, 1933, when it contained two incubated eggs. The nest was on 

 the ground at the base of a precipice. It was a loosely made cup of 

 coarse straw, grass, and leaves, lined with very fine grass stems and 

 skunk hair. Outside dimensions of the nest were 11.5x12.7x7.5 cm, 

 the cup 6.2 X 3 cm. The two eggs were bluish white, generously and al- 

 most evenly speckled with lilac and reddish brown; they measured 20 X 

 16 and 20.5x16 mm. (Blake, Condor, 1956, p. 388). In Costa Rica, 

 Skutch (Publ. Nutt. Orn. Club, no. 7, 1967, pp. 204-205) has found 9 

 sets of two eggs and 2 sets of three eggs. The nests he found were lo- 

 cated on the ground in a bank sheltered from rain, in thorny shrubs, 

 and, once, on a beam in a cowshed, 3 m above the ground. Ten adult 

 specimens collected by Leek (Bird-Banding, 1975, p. 202) at Cerro 

 Punta, Chiriqui weighed from 18.7 to 23.2 g. 



At Cerro Campana I found the birds ranging over open, grass- 

 covered ridges, where exposures of volcanic rock thrust out from the 

 poor, stony soil, and woody vegetation is composed of low, scrubby 

 growth in sheltered valleys, only scattered shrubs appearing elsewhere. 

 The sparrows remained mainly on the grassland, perching on boulders 

 or in the low bushes. They were found from 540 m upward. In 1951, 

 the birds were common and I heard several singing there on June 21, 

 1953, when they were quite shy, but on December 21, 1955, it took con- 

 siderable search to find a group of 3. I believe that the heavy and com- 

 plete burning of the grasslands, which had taken place since my previ- 

 ous visit, had a definite effect on their number. On March 2, 1951, I 

 collected a series of males that were in or near breeding condition. One 

 was carrying food in its throat. I flushed 2 from grass at my feet that 

 I was certain were females that had come off nests, but I could find 

 nothing. 



