FAMILY TYRANNIDAE 465 



ready to shift about again. Rarely, in the beginning of March I heard 

 them calling, a low note, ivee-soo, given with some emphasis. I found 

 it difficult in the cover that they often frequented to distinguish them 

 from small native flycatchers. Most of those taken in March were 

 molting, this including the feathers of the wings. 



They ate insects, the usual food of this species, and also small 

 berries. On the whole they were quiet in their movements, and so 

 did not attract attention. 



EMPIDONAX VIRESCENS (Vieillot) : Acadian Flycatcher, 

 Moscareta Verdosa 



Platyrhynchos vircsccns Vieillot, Nouv. Diet. Hist. Nat., nouv. ed., vol. 27, 

 December 1818, p. 22. (Near Philadelphia, Pennsylvania.) 



Empidonax griseigiilaris Lawrence, Ann. Lye. Nat. Hist. New York, vol. 7, 1862, 

 p. 471. (Atlantic slope, Panama Railroad, Canal Zone, Panama.) 



Small ; grayish olive-green above, two pale buff or white wing bars ; 

 a white eye-ring. 



Description. — Length 125-140 mm. Adult (sexes alike), above 

 grayish olive-green, with crown faintly darker; wings grayish brown 

 to dusky ; middle and greater coverts tipped with huffy white or buff, 

 forming two prominent wing bars ; secondaries edged narrowly with 

 the same; tail grayish brown, with the outer webs of the outer pairs 

 of feathers faintly paler; lores mixed with dusky and whitish (often 

 indistinctly); a white eye-ring; sides of head and neck like back, 

 fading below into the paler color of the throat, which is yellowish 

 white ; upper breast and sides shaded with pale grayish olive ; rest of 

 under surface yellowish white, usually more yellow on the abdomen 

 and on the under tail coverts ; axillars and under wing coverts pale 

 yellow ; inner webs of wing feathers edged with grayish buff. 



Measurements. — Males ( 10 in breeding season, from South Caro- 

 lina and Tennessee north to Pennsylvania), wing 73.5-77.6 (75.6), 

 tail 57.6-61.7 (59.7), culmen from base 14.8-16.0 (15.4), tarsus 

 15.7-16.3 (15.9) mm. 



Females (10 in breeding season, from Georgia to Kentucky and 

 New York), wing 68.1-71.6 (69.9), tail 53.0-56.6 (54.9), culmen 

 from base 14.5-15.7 (15.0), tarsus 14.6-15.7 (15.1) mm. 



Winter visitor from the North. Common ; mainly through the 

 lowlands, less frequently to 1760 meters at Cerro Punta and Nueva 

 Suiza, Chiriqui ; 1250 meters on Cerro Tacarcuna, Darien; Isla 

 Taboguilla. 



Acadian Flycatchers begin to arrive early in September (Barro 



