FAMILY VIREONIDAE 



229 



Campana and Rio Indio show slightly more than average. In an old 

 series from Gatun, Canal Zone, all but one are gray-crowned with 

 variable green edging to the feathers; the exception is all green and 

 has been identified as H. d. darienensis. Two specimens from Juan 

 Mina, Canal Zone, are nearly intermediate, but tending more toward 

 gray. In 2 from Cerro Azul, to the east, 1 is an intermediate and the 

 other darienensis. A specimen from Pacora still shows a trace of gray, 

 while those from Chepo eastward are all darienensis. 



Ridgely (1976, p. 286) describes the call of this species as "a rapid 

 musical phrase suggestive of a single phrase of the Yellow-green Vireo 

 but even more monotonous, constantly repeated, typically deedereet or 

 itsacheet." Eisenmann (Smiths. Misc. Coll. vol. 117, no. 5, 1952, p. 

 49) says the call is given at intervals of about 5 seconds. E. S. Morton 

 (in litt. to Eisenmann) could find no constant difference between vo- 

 calization in the Canal Zone of birds with predominantly gray crowns 

 and those on Cerro Azul with completely olive-green or mixed crowns. 

 A series he collected shows every variation between green and gray 

 crown; moreover, seeming pairs included differently colored indi- 

 viduals. 



HYLOPHILUS DECURTATUS DECURTATUS (Bonaparte) 



Sylvicola decurtata Bonaparte, 1838, Proc. Zool. Soc. London, 5(1837), p. 118. 

 (Guatemala.) 



Hylophilus pusillus Lawrence, 1862, Ann. Lyc. Nat. Hist. New York, 7, p. 323. 

 (Atlantic side of Isthmus of Panama.) 



Characters. — Crown gray. 



A male taken February 18, 1966, at Puerto Armuelles, Chiriqui had 

 the iris brown; maxilla except cutting edge fuscous-black; cutting edge 

 and mandible pale neutral gray; gape dull honey yellow; tarsus, toes, 

 and claws neutral gray; lower surface of toe pads dull honey yellow. 



Measurements. — Males (10 from western Panama), wing 50.8- 

 54.4 (52.7), tail 32.6-38.9 (35.3), culmen from base 11.8-13.6 (12.7), 

 tarsus 14.6-17.2 (16.3) mm. 



Females (8 from western Panama) , wing 45.3-50.8 (47.7) , tail 28.7- 

 36.6 (32.5 ) , culmen from base 1 1.7-13.8 ( 12.4) , tarsus 15.2-16.8 ( 16.1 ) 

 mm. 



Resident. Common in lowland forest, second-growth woodland, 

 and coastal mangrove forest recorded on Volcan de Chiriqui as high 

 as 1800 m (Blake, Fieldiana: Zool., vol. 36, no. 5, 1958, pp. 554- 

 555). Aldrich and Bole (Scient. Publ. Cleveland Mus. Nat. Hist., vol. 

 7, 1937, p. 24) found it common in semi-deciduous coastal forest, be- 



