364 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



84. Upper surface bright olive-green, with crown only faintly, if at all, grayer 



than back ; foreneck and breast only faintly grayish. 



Yellow-green tyrannulet, Phylloscartes flavovircns, p. 539 



Upper surface somewhat duller olive-green with crown definitely darker 



than back ; breast distinctly grayish 85 



85. Crown light greenish gray ; mandible flesh color ; scutes on lower end of 



tarsus roughened. 



White-fronted tyrannulet, Acrochordopus seledoni zeledoni, p. 580 



Darker, duller in color above, with crown blacker ; entire bill dark colored ; 



scutes on lower end of tarsus smooth 86 



86. Wing coverts and secondaries edged with greenish yellow ; back and tail 



edgings dull greenish ; breast and abdomen whitish. 



Paltry tyrannulet, Tyranniscus vilissinuis parvus, p. 575 



Wing coverts and secondaries tipped and edged with brownish white to 



white ; back and wings duller, less greenish ; lower breast and abdomen 



yellow Crested tyrannulet, Phyllomyias griseiceps cristatus, p. 573 



SAYORNIS NIGRICANS (Swainson) : Black Phoebe, Tiguin de Agua 



Tyranmda nigricans Swainson, Phil. Mag., n.s., vol. 1, May 1827, p. 367. 

 (Tableland of Mexico.) 



Medium size ; in life, appearing black ; usually perching on rocks 

 along streams. 



Description. — Length 155-170 mm. Adult (sexes alike), head and 

 neck dull black; rest of body sooty slate to dull slate; wing coverts, 

 wing feathers, and outer rectrix edged with white (varying from 

 slight to extensive, according to the subspecies ) ; abdomen with more 

 or less white ; axillars and under wing coverts varying from white to 

 dull gray. 



The black phoebe is found along rock-strewn stream beds, mainly 

 in the upper Tropical and Subtropical zones, but also at lower levels 

 in areas suited to its needs. While it ranges in the open it is not 

 conspicuous, as it rests quietly on stones and other low perches in 

 trees and bushes usually near water. The tilting flight from one rest- 

 ing place to another is low, near the water or stream bed. When 

 perched, the tail is twitched and the bird turns the head about, watch- 

 ing for insects which it captures on the wing or follows to the ground. 



The call is a single low note, chip or tsip uttered as the birds rest. 

 The song is a continued repetition of two low notes uttered together : 

 pee wee, often with the pair of sounds repeated alternately with rising 

 and with falling inflection. Occasionally the birds circle in air while 

 singing. 



The nest is a strongly made cup. built with fine bits of dry grass 

 and other similar material, held in place by a plaster of mud. This 



