178 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



KEY TO SPECIES OF SYLVIIDAE 



1. Upper surface brown, bill very long 2 



Upper surface gray, bill relatively short 3 



2. Undersurface below throat buffy, tail long. 



Long-billed Gnatwren, Ramphocaenus melanurus rufiventris. p. 183 

 Undersurface below throat gray, tail short. 



Tawny-faced Gnatwren, Microbates cinereiventris. p. 186 



3. General coloration light bluish gray. 



Tropical Gnatcatcher, Polioptila plumbea. p. 178 

 General coloration dark slaty gray. 



Slate-throated Gnatcatcher, Polioptila schistaceigula. p. 182 



POLIOPTILA PLUMBEA (Gmelin): Tropical Gnatcatcher, 

 Cazajejen Tropical 



Figure 15 



Todus plumbeus Gmelin, 1788, Syst. Nat., 1, pt. 1, p. 444. (Surinam.) 



Small, slender, with long tail; upper surface gray and black; under- 

 surface light gray and white. 



Description. — Length 92-103 mm. Adult male, crown, hindneck, 

 and upper parts of sides of neck black, with a tiny white feather or two 

 behind the nostril; back, scapulars, rump, and wing coverts bluish 

 gray; primaries and secondaries dusky neutral gray, with outer webs 

 edged with slate gray, except for the two outer primaries; tertials edged 

 broadly with white on outer webs, the edging becoming pale neutral 

 gray toward the tip; tail black centrally, the two outermost rectrices 

 white, the next two black at base, the fourth black, tipped white; lores 

 and a broad superciliary white; eye-ring white; a conspicous black line 

 extending from the eye to the back of the nape; rest of side of head, 

 throat, ventral area of sides of neck, abdomen, and undertail coverts 

 white; rest of undersurface pale bluish gray; underwing coverts, and 

 inner webs of primaries and secondaries, toward the base, white. 



Adult female, like male, but upper surface entirely dark bluish gray, 

 without black on the head. 



Juvenile male, like adult female but crown slate-gray and white su- 

 perciliary not fully developed behind eye. 



The Tropical Gnatcatcher is a widespread species, occurring from 

 southeastern Mexico to central Peru and central Brazil, with habits 

 similar to the Blue-gray Gnatcatcher (P. caerulea) of temperate North 

 America. In Panama it is found up to about 1200 m almost every- 

 where that there are trees, from forest canopy and borders to scrubby 

 areas to brushy savannas (Aldrich and Bole, Scient. Pub. Cleveland 



