6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I43 



Very small. Sexes nearly identical : gray above, with a black cap, and 

 white superciliary stripes, and largely yellow below. 



Resident in Panama. Common both in young second-growth forest 

 and scrub, and along the edges of fairly mature forest, in low bushes 

 as well as in the treetops. 



Only very slightly gregarious apart from mixed species flocks. 

 Active. Very noisy during the breeding season, when the males may 

 utter shrill monotonous songs for hours on end. 



Yellow Warbler (Dendroica petechia). — All the yellow warblers 

 observed with mixed species flocks during this study appeared to be 

 migrants belonging to the subspecies aestiva which breeds in North 

 America. They were largely yellow with rufous on the crown (but not 

 over the whole head, as in the resident race erithachorides) . They 

 were observed only during the Northern Hemisphere winter. 



In Panama these warblers are widely distributed and moderately 

 common. They are active, but silent, and almost completely nongre- 

 garious apart from mixed species flocks. 



Streaked and Buff-throated Saltators (Saltator albicollis and S. 

 maximus). — Relatively large finches. In both species the sexes are 

 nearly identical. The streaked saltator is grayish olive above, with 

 white superciliary stripes, and whitish below, streaked with grayish 

 olive. The buff-throated saltator is largely olive above and gray below, 

 with white superciliary stripes and a buff throat bordered by black. 



Both species are resident in Panama and most common in young 

 second-growth forest. They are primarily birds of the treetops and 

 the upper levels of moderately high shrubbery. 



They are not very active or noisy, and only slightly gregarious 

 apart from mixed species flocks. 



OTHER SPECIES 



The species described above are the ones that occur most frequently 

 in the blue and green tanager and honeycreeper flocks in central 

 Panama, in the Canal Zone and adjacent areas. 



Many other species may also occur in such flocks, but much less 

 frequently, either because they themselves are rare, or because they 

 are not attracted to such flocks very strongly. Among these species 

 are the scarlet-thighed dacnis (Dacnis venusta), the white- winged 

 tanager (Tachyphonus luctuosus), the yellow-rumped tanager (Ram- 

 phocelus icteronotus) , the resident yellow-tailed and yellow-backed 

 orioles {Icterus mesomelas and /. chrysater), the migrant Baltimore 

 oriole (/. galbula), the clay-colored thrush (Turdus grayi), a variety 



