l 4 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



Gulf of Panama and other waters of the Pacific in the direction of 

 Darien or Colombia. Thus, single birds or small groups of Barn Swal- 

 lows may appear on any of the offshore islands. In stormy weather 

 during periods of migration, hundreds may be encountered. Northward 

 migration is evident by late March and continues into late May, when 

 it becomes difficult to separate northern travelers from summering 

 birds. Birds such as the 2 seen by Eisenmann at Coco Solo, Canal Zone, 

 on July 23, 1956, could be summering or early transients moving south- 

 ward. 



Migrant and wintering groups gather at night to sleep in low trees or 

 reeds around lowland lagoons and marshes, spreading widely in their 

 feeding activities during the day. The roosts are in the open. In 1966, 

 at Puerto Armuelles, Chiriqui, the Chiriqui Land Company had built 

 a roof over a long pier to allow handling of extensive shipments of 

 bananas regardless of weather. During February and March, Barn 

 Swallows gathered nightly to sleep under this shelter, undisturbed by 

 the electric lights that illuminated the area throughout the night, or the 

 workmen busy beneath them. 



The annual molt of adults and young comes during the months of 

 northern winter. The full-plumaged birds seen regularly in early May 

 are assumed to be those that will nest in the more northern parts of the 

 breeding range in Alaska and Canada. 



Ridgely (in litt.) notes that in recent years Barn Swallows have in- 

 creasingly come to be associated with sugarcane fields, especially dur- 

 ing northern winter months; they hawk for insects over and around 

 them, and also roost in them. This seems to be the pattern as far south 

 as eastern Brazil. The considerable increase in Barn Swallows in the 

 past decade may be associated with the great increase in sugar growing 

 in Pacific slope lowlands of Panama. 



PETROCHELIDON PYRRHONOTA (Vieillot): Cliff Swallow, 

 Golondrina de Paso 



Medium size. Tail short, slightly notched at tip; forehead white, buff 

 or chestnut-brown; rest of crown black or dusky; rump buff to brown. 



Description. — Length 120-151 mm. Adult (sexes alike), crown and 

 back shining blue-black; forehead white to chestnut (according to 

 race) ; rump cinnamon-rufous; upper tail coverts grayish brown, edged 

 with paler gray; wings and tail dusky brown; secondaries edged nar- 

 rowly with white toward the tips; lores blackish; side of head and fore- 

 neck chestnut, in some this color extending narrowly across hindneck; 



