FAMILY FRINGILLIDAE 



559 



the birds become somewhat more territorial. Their food is mainly grass 

 seeds; 1 collected by E. A. Goldman had the stomach 98% rilled with 

 shelled seeds of Paspalum sp. and Panicum sp., and 2% ant and beetle 

 remains. The male has a very distinctive territorial display in which, 

 with the aid of his wings, he jumps vertically 12 to 18 inches and drops 

 to the same perch. Sometimes the jump is accompanied by a buzzy call 

 that has been rendered variously as t-s-e-u, bzee-eep, and dzee-ew. I 

 have also heard a rattle of wings. Frequently the male rotates the direc- 

 tion he faces in each succeeding hop and may hop once every 15 seconds 

 for a half hour or more. In addition to using hopping displays as terri- 

 torial markers, a series of shorter hops may serve to intimidate an 

 enemy. Alderton (Condor, 1963, p. 156) observed a male drive a 

 lizard from 2 juveniles just out of the nest in this manner. 



This species has a long breeding season: Dr. Pedro Galindo found a 

 nest at Almirante, Bocas del Toro, on May 5, 1962; the season peaks in 

 September and continues into October (Alderton, op. ext., p. 162). 

 Courtship involves the same kinds of hops as are used in territorial dis- 

 play. The nest is built by both sexes. It is a small shallow cup made of 

 tendrils, rootlets, and grass stems placed in a bush or grass from a few 

 centimeters to 3 meters above the ground; most are within 3 m of the 

 ground. For nine nests measured by Alderton the outside diameter 

 ranged from 4.5 to 8 cm, the inside diameter from 4.5 to 5 cm, the out- 

 side depth from 4 to 5.5 cm, and the inside depth from 2.5 to 4 cm. 

 Barnard (Condor, 1956, p. 229) observed grassquits taking apart a 

 nest of theirs that had been destroyed and rebuilding it elsewhere. The 

 usual clutch is 3, although nests containing 2 are not uncommon. The 

 eggs are bluish white with brownish or purplish spots slightly con- 

 centrated at the larger end. Three eggs in a clutch collected by Major 

 General G. Ralph Meyer at Balboa, Canal Zone, on June 14, 1941, 

 measured 16.8x12.1, 16.1x12.4, and 17.0x12.4 mm. Incubation is 

 performed by both parents, although primarily by the female, and 

 takes from 10 to 12 days. Both parents feed the young, which remain 

 in the nest for 9 days and depart when not yet well feathered. Some- 

 times a pair will build two or three nests in a season, but these are 

 usually birds whose earlier nests were not successful. 



TIARIS OLIVACEA (Linnaeus): Yellow-faced Grassquit, 

 Arrocero Yerbero 



Emheriza olivacea Linnaeus, 1766, Syst. Nat., ed. 12, 1, p. 309. (Hispaniola.) 



Very small; male, superciliary and chin yellow; forehead, and in 

 T. o. ravida entire head, black; rest of upper surface green; throat and 



