FAMILY HIRUNDINIDAE 



^5 



PROGNE SUBIS HESPERIA Brewster 



Progne subis hesperia Brewster, Auk, vol. 6, no. 2, April 1889, p. 92. (Sierra de la 

 Laguna, Baja California, Mexico.) 



Characters. — Adult male, like nominate subis but smaller; female 

 and immature male averaging paler in general coloration; foreneck, 

 breast, and sides more extensive, white to pale grayish white. 



M easurements. — Males ( 10 from Baja California) , wing 140.5-145.0 

 (142.2), tail 65.0-70.3 (67.7), culmen from base 13.4-15.9 (14.8), 

 tarsus 14.9-15.9 (15.2) mm. 



Females (6 from Baja California), wing 136.1-140.7 (138.2), tail 

 62.1-68.0 (66.6), culmen from base 13.5-15.6 (14.8), tarsus 14.8-15.5 

 (15.1) mm. 



Passage migrant to and from winter quarters in South America. 

 Known definitely in Panama from a male in immature plumage in the 

 American Museum of Natural History, collected by R. R. Benson, at 

 Cocoplum, Bocas del Toro, October 27, 1927. 



Zimmer (Amer. Mus. Nov., no. 1723, 1955, pp. 4, 5) listed this 

 specimen, but with information available at the time was uncertain as 

 to the characters of hesperia. The bird, on examination, is an immature 

 male in good plumage, with the paler coloration of hesperia, evidently 

 a bird from the preceding summer. With a wing measuring 143.6 mm, 

 it is within the size limits accepted for this race. 



An early report of this race in migration is that of Richmond (Proc. 

 U. S. Nat. Mus., vol. 16, 1893, p. 485). He collected a pair of Purple 

 Martins September 13, 1892, in eastern Nicaragua, on a banana plan- 

 tation on the Rio Escondido 50 miles above Bluefields, from "a flock 

 of six or eight which had settled in the top of a dead tree during a 

 shower." These 2 specimens (in the Smithsonian) belong to the sub- 

 species hesperia and mark the first record for migrants of this form. 

 Wing measurement for the male is 144.1 mm, for the female, 133.6 mm. 



PROGNE ELEGANS Baird: Southern Martin, Golondrina Negra 



Progne elegans Baird, Rev. Amer. Birds, May 1865, pp. 274 (in Key), 275. (Ver- 

 mejo River, Paraquay = Rio Bermejo, Argentina.) 



Closely similar in appearance to Progne subis, but on average 

 slightly smaller; in adult male blue sheen faintly duller, less brilliant; 

 female more heavily marked below and lacking pale forehead and sides 

 of neck; tail more deeply forked than in subis. 



Description. — Length 175-185 mm. Male, with concealed white on 

 sides and flanks like subis, but with undertail coverts duller, less clearly 



