22 BIRDS OF THE REPUBLIC OF PANAMA PART 4 



of southern South America is highly migratory and regularly reaches 

 Suriname, northern Brazil, and Venezuela; at least occasional occur- 

 rence in Panama is not improbable during the austral winter but speci- 

 men examination would be required. As in P. elegans, the molting 

 primaries in July would be a strong clue that domestica was involved 

 (see Eisenmann, Auk, 1959, pp. 528-532). 



PROGNE SUBIS (Linnaeus): Purple Martin, Golondrina Azul 



Largest of the swallows found in North and Central America (aver- 

 aging larger than the Brown-chested Martin, Progne tapera) . 



Description. — Length 170-200 mm. Adult male glossy dark steel 

 blue above and below; partly concealed feather tufts on sides of lower 

 back white; primaries dull black, with the basal area of the shafts dull 

 white basally, changing to dull brown for the remainder of the length. 



Adult female, duller colored above (through partial exposure of the 

 basal area of the feathers); forehead and more or less of forecrown 

 sooty gray to white (varying racially and individually in depth of 

 color); lores and auricular region dusky; sides of neck grayish, many 

 individuals with an indefinite dull grayish band across the hindneck; 

 anterior lower surface sooty gray, tipped narrowly with dull grayish 

 white; lower breast, abdomen, and undertail coverts white, in some 

 streaked indefinitely with sooty gray; sides, underwing coverts, and 

 axillars dark sooty gray. 



Immature (both sexes), like female but duller above, with glossy 

 area mainly on crown; wing coverts and secondaries tipped narrowly 

 with dull grayish brown; collar across hindneck usually distinct. 



The Purple Martin is widely distributed in the nesting season from 

 Baja California, and the mountain areas in the central plateau of 

 Mexico; northward irregularly through the United States to Vancouver 

 Island and southern British Columbia, and central eastern Canada. 

 Following the breeding season, adult and immature martins gather at 

 night in tree roosts that may include hundreds (even thousands) of 

 individuals. At the end of August and in early September these groups 

 disappear as the birds move southward to wintering grounds in South 

 America. In spring when they return north they appear individually or 

 in small groups on their nesting grounds. 



Two geographic races have long been recognized, the nominate form, 

 Progne subis subis, being the breeding bird found widely through the 

 United States north to south-central Canada. The slightly smaller and 

 paler subspecies, Progne subis hesperia, is the nesting form of Baja 



