FAMILY TYRANNIDAE 365 



may now be under the eaves of a building or attached to beams be- 

 neath a bridge. In its primitive condition it was attached to some 

 sheltered crevice under cover of a huge stone. Skutch in his account 

 of this bird in the tropics (Pac. Coast Avif. no. 34, 1960, pp. 365- 

 373) records two or three eggs in a set, sometimes plain white, some- 

 times white dotted with small reddish spots. Nests are built by the 

 female, who also incubates and cares for the young. The northern 

 subspecies 6". ;;. semiatra, resident from California, southwestern 

 Utah, and central Texas, southward to northern Mexico, appears sub- 

 ject to greater annual stresses as its eggs vary in number from three 

 to six, usually four or five, in a set. 



SAYORNIS NIGRICANS AMNICOLA Bangs 



Sayornis amnicola Bangs, Proc. New Engl. Zool. Club, vol. 3, January 30, 1902, 

 p. Z7. (Boquete, 1220 meters elevation, Chiriqui, Panama.) 



Characters. — White edgings on wings and outer tail feathers much 

 reduced, in some nearly absent ; less white on abdomen. 



A male, taken at Palo Santo, Chiriqui, March 2, 1965, had the iris 

 very dark brown ; thickened edge of the eyelids dull black ; tarsus, 

 toes, and claws black. 



Measurements. — Males (10 from Chiriqui and Costa Rica), wing 

 83.5-91.0 (88.0). tail 70.9-79.0 (75.9). culmen from base 15.7-17.6 

 (17.0). tarsus 17.2-18.8 (18.1) mm. 



Females (7 from Chiriqui and Costa Rica), wing 77.7S3.5 (80.9), 

 tail 67.0-73.7 (70.5). culmen from base 16.0-17.6 (16.5), tarsus 

 16.5-17.6 (17.2) mm. 



Resident. Found locally along mountain streams in the upper 

 Tropical and lower Subtropical zones in western Chiriqui : to 1625 

 meters above Boquete ; Bocas del Toro, on the Rio Changuinola, be- 

 tween Boca del Rio Risco and Punta Blanca. 



While not abundant, this flycatcher is widely distributed in the 

 more open valleys of the larger foothill and mountain streams in 

 western Chiriqui. I have seen it especially along the Rio Chiriqui 

 Viejo from Barriles to Cerro Punta. and in other tributary rivers 

 westward toward Costa Rica. It was not recorded here by Arce or 

 others prior to 1900, so that it seems probable that it has grown in 

 number, following the clearing of forests which has greatly increased 

 suitable habitat along the major rivers. On March 2, 1960, Charles 

 O. Handley, Jr.. recorded it on the Rio Changuinola, in Bocas del 

 Toro. the only record for that province. The locality is within the 

 foothills. 



