BIEDS OF NORTH AND MIDDLE AMERICA. 589 



DENDROICA PENSYLVANICA (Linnaeus). 

 CHESTNOT-SIDED WARBLER. 



Adult male.^ — Forehead and crown olive-yellow, the former becom- 

 ing whitish anteriorly, both sometimes flecked with dusky; lores, sub- 

 orbital region, malar region, postocular stripe, occiput, and hindneck 

 black, the last two streaked with white, grayish, or yellowish, the occi- 

 put usually with a central spot of white or yellowish; auricular region, 

 sides of neck, chin, throat, and under parts white, relieved by a broad 

 lateral stripe of rich chestnut, extending from posterior extremity of 

 black malar stripe along the sides, usually to the flanks, but sometimes 

 not beyond sides of breast; back and scapulars broadly streaked with 

 black on a white, grayish, and olive-3'ellow ground, the last-mentioned 

 color usually prevailing; rump usually yellowish olive-green, some- 

 times grayish, with or without black streaks; upper tail-coverts black, 

 broadly margined with light gra}^ (sometimes tinged with yellowish 

 olive-green); tail black with narrow olive- grayish edgings, the three 

 outermost rectrices with inner webs extensively white terminally, that 

 on the exterior rectrix occupying the terminal half, or more; wings 

 black with yellowish oliv^e-green edgings (becoming grayish on prima- 

 ries and primary coverts), the middle and greatej" coverts broadly 

 tipped, the latter also edged, with sulphur yellow; lesser coverts mar- 

 gined with gray or olive-gra}"; bill blackish, the mandible inclining to 

 dusky horn color, especial!}^ basally; iris brown; legs and feet dusky 

 brown; length (skins), 111.8-121.9 (115.7); wing, 61.2-67.1 (63.3); 

 tail, 48.5-52.6 (50.1); exposed culmen, 9.4-9.9 (9.6); tarsus, 17-18.3 

 (17.8); middle toe, 10.2-10.9 (10.6).' 



Adult female. — Similar to adult male, but duller in color, the fore- 

 head and crown light olive-green rather than olive-3'ellow, the black 

 areas on sides of head less deep black, often much broken by grayish 

 streaking or mottling, sometimes replaced h\ grayish and much more 

 restricted; chestnut of sides averaging less extensive; greater wing- 

 coverts without yellow edgings;^ length (skins), 106.7-116.8 (111.8); 

 wing, 57.9-61.5 (69.3); tail, 45-48.5 (46.7); exposed culmen, 9.1-9.9 

 (9.5); tarsus, 17-18 (17.6); middle toe, 9.6-10.4 (10.3).'' 



Young in first autumn and whiter. — Above plain bright olive-green, 

 the back and rump with concealed, or mostly concealed, black or 



^ Judging from the scant material from Central America, the phmiage appears to be 

 the same in winter as in spring and summer; specimens examined are without dates, 

 however. 



■^ Seven specimens. 



^The adult female varies so much, individually, in coloration that a satisfactory 

 diagnosis is difficult. The brighter colored females are scarcely, if at all, distin- 

 guishable from duller colored males; the average, however, are decidedly duller, while 

 some have the crown olive-green, the black head markings obsolete, and the chest- 

 nut of sides limited to a few isolated touches. 



