34 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



incubating and caring for the young. At night, one parent slept on the 

 eggs while the other rested on the rim of the nest. The newly hatched 

 young have a sparse covering of light gray down. A second brood may 

 come in June. When mated, the pair remains together throughout the 

 year following the breeding season. 



In most of their activities, I have noted that these swallows are 

 mainly silent. The song is described as "a thin, weak, long-continued 

 trill which slides upward at the end." 



One egg in the British Museum collection that I examined, taken by 

 Underwood on Volcan Irazu, Costa Rica, April 25, 1901, was white, 

 without markings and measured 16.9 X 12.6 mm. The maximum sizes 

 (listed by Meise in Schonwetter, Handb. Ool., pt. 17, 1970, p. 193) 

 which range larger, to 20 X 14 mm, in part may include specimens from 

 South American localities where nominate cyanoleuca is not found. 



Fleas parasitic on birds are little known, so it is of interest to report 

 one captured on a specimen of this northern race of the Blue-and- white 

 Swallow, in March 1962, by Vernon J. Tipton and C. L. Hay ward. 

 In a report on the fleas (Siphonaptera) of Panama by Tipton and 

 Eustorgio Mendez (in Wenzel and Tipton, Ectoparasites of Panama, 

 Field Museum of Natural History, 1966, p. 310) this parasite is listed 

 as Dasypsyllus sasius venezuelensis (I. Fox and Anduze), with the 

 comment that it was abundant in swallows' nests, both in buildings and 

 in earth banks. "In one hole in an earth bank the fleas were very 

 numerous in the sand below the scanty nesting material." 



NOTIOCHELIDON CYANOLEUCA PATAGONICA 

 (D'Orbigny and LafresnayeJ 



Hirundo patagonica D'Orbigny and Lafresnaye, Syn. Av., in Rev. Zool., ann. 7, 

 1837, p. 69. (Patagonia.) 



Characters. — Adult, with only the lower half of the undertail coverts 

 black, the upper area being white like the rest of the undersurface; 

 underwing coverts paler grayish brown. 



Immature, with underwing coverts much paler gray; undertail co- 

 verts paler with tips more extensively white. 



Measurements. — Males ( 10 from Darien, Argentina, Peru, and Ven- 

 ezuela), wing 101.2-111.9 (104.5), tail 50.1-55.6 (52.6), culmen from 

 base 7.1-8.5 (7.8), tarsus 11.1-12.4 (11.8) mm. 



Females (10 from Darien, Argentina, and Chile), wing 99.2-105.6 

 (102.8), tail 44.7-57.1 (48.7), culmen from base 7.5-9.5 (8.2), tarsus 

 11.4-12.6 (12.0) mm. 



Migrant from southern South America; of irregular occurrence. 



