FAMILY CAPRIMULGIDAE 205 



band; tail with mottled bars of grayish white or pale buff; neck and 

 upper breast mainly dull black, mottled with indistinct bars of white to 

 buff; a prominent band of white, often washed with buff, across the 

 upper f oreneck ; breast, sides, abdomen, and under tail coverts white 

 to buff, barred narrowly with dull black ; edge of wing white ; a white 

 band across inner webs of primaries nearly at center of wing. 



The races of the common nighthawk that nest in North America 

 are migrant to South America. Three forms of these northern birds 

 have been recorded from Panama, in addition to the population that 

 is resident. It is probable that other migrant races will be found in 

 due course. 



The two species of the genus found in Panama are so similar in 

 appearance when flying that identification by sight is uncertain. The 

 voice of the common nighthawk is a loud, single note, peent, and males 

 in display frequently dart downward in the air for several meters, and 

 then, in an abrupt turn at the end of the descent, through air rushing 

 past the wings produce an abrupt roaring sound audible at a con- 

 siderable distance. These identify the breeding males immediately, 

 but do not serve with migrants as these birds do not display. When 

 clearly seen at rest the position of the white spot in the wing serves to 

 separate the two, but otherwise usually there will be doubt in sight 

 identifications. Most of the migrants pass through rather rapidly. To 

 the present they have been recorded only in September and October. 

 The period of the spring flight is not known. It is probable that their 

 migrations are mainly along the Caribbean coast. 



CHORDEILES MINOR MINOR (Forster) 



Caprimulgus minor J. R. Forster, Cat. Anim. North Amer., 1771, p. 13. 

 (South Carolina.) 



Characters. — Decidedly darker, blacker above, with fewer pale 

 markings ; lower surface usually with dusky bars broader. 



Measurements. — (From Ridgway, U. S. Nat. Mus. Bull. 50, pt. 6, 

 1914, p. 563.) Males, wing 184-208 (198), tail 106-118 (110.9) mm. 



Females, wing 187.5-203 (196.5), tail 105-118.5 (112) mm. 



Migrant from the north, abundance uncertain. 



Recorded (by specimens) in Bocas del Toro (Rio Sixaola, Carriker, 

 Sept. 24, 1904), Canal Zone (McLeannan, date not recorded), and 

 San Bias (Perme, Wedel, Oct. 15, 1929). 



