FAMILY PARULIDAE 



303 



in litt. to Eisenmann) . Extreme dates from Panama (fide Eisenmann) 

 are September 24-May 2. Willis (Living Bird, 1966, p. 209) considers 

 the Hooded Warbler to be an ecological competitor of the Spotted Ant- 

 bird (Hylophylax naevioides) and suggests that this is why the warbler 

 is locally rare or absent as a winter resident wherever the antbird occurs. 



A male collected at Almirante by D. L. Hicks on October 25, 1964, 

 weighed 8 g. 



WILSONIA PUSILLA (Wilson J: Wilson's Warbler, Reinita de Wilson 



Small; mid-crown black; upper surface bright olive-green; forehead 

 and undersurface yellow. 



Description. — Length 103-115 mm. Adult male, forehead, super- 

 ciliary, and orbital ring bright yellow; center and rear of crown shin- 

 ing black; auriculars and rest of upper surface bright olive-green; 

 wings and tail dusky, with wing coverts tipped and rectrices and remiges 

 edged olive-green; undersurface, bend of wing, and underwing coverts 

 bright yellow. 



Adult female, like male, but black on crown less extensive or absent. 



Wilson's Warbler is an abundant winter resident in the highlands of 

 Chiriqui, where, at El Volcan, I saw as many as a dozen together, on 

 March 13, 1954. In the highlands and foothills farther east it becomes 

 progressively less common. It is seen regularly in small numbers above 

 Santa Fe, Veraguas, but in central Panama there are only 3 sight rec- 

 ords, all of males: 1 on Cerro Campana on September 14, 1961 (R. 

 Ryan), and single individuals on Cerro Azul on December 30, 1967, 

 and December 28, 1973 (Ridgely, 1976, p. 302). Panama is the south- 

 ern limit of this species' range in winter. Panama records (fide Eisen- 

 mann) run from September 10 to May 16 (both specimen records) . 



Leek (Bird-Banding, 1975, p. 202) found that 15 Wilson's Warblers 

 mist netted at Cerro Punta, Chiriqui, during September and October 

 1967 had an average weight of 7.6 g and 12 netted there in March 1968 

 averaged 8.0 g. 



I have seen Wilson's Warblers feeding in herbaceous growth near 

 the ground and as high as 10 m up in second growth. They are often 

 common in coffee plantations. This is the most numerous and con- 

 spicuous wintering wood warbler in the Chiriqui highlands. Ridgely 

 (in litt. ) has seen up to 30-35 in a day in Chiriqui and in the Costa Rica 

 highlands as well. 



Eisenmann (in litt.) noted that in the Chiriqui highlands Wilson's 

 Warblers favor semi-open or lightly wooded areas. He found them 

 usually moving about in the mixed bands of wandering warblers and 



