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Order APODIFORMES 

 Family APODIDAE: Swifts, Vencejos 



This family, the true swifts, distributed worldwide in tropical lands, 

 has a few kinds that range in the warmer season of the year to regions 

 of temperate summers, mainly in the Northern Hemisphere. At the 

 approach of cold weather the latter migrate to winter quarters far to 

 the south. Swifts are birds with long, narrow wings and compact, 

 muscular bodies, distinguished from swallows of similar form by their 

 far more rapid, dashing flight, and by their remaining constantly in 

 the air. To nest and to rest they enter hollow trees or other cavities, 

 or seek cliffs where they cling with sharp claws, bodies pressed against 

 the surface. Only in their nests do they rest prone. Their food, entirely 

 of small insects, is captured on the wing in the gape of the widely 

 opened mouth. They drink in similar manner by sweeping down to 

 scoop water on quiet surfaces of ponds and streams. 



Eleven of the 65 species known are found in Panama. Three of 

 these, the cloud swift, the Cayenne swift, and the male chestnut- 

 collared, are readily identified in life. The others, similar in general 

 in size and color pattern, usually may be recognized only with the 

 bird in the hand. And then by details of color and pattern that differ 

 so little that it is surprising to realize that they mark distinct species. 



KEY TO SPECIES OF APODIDAE 



1. Size large ; wing 190 mm. or more. 



White-collared swift, Strcptoprocne sonaris albicincta, p. 224 

 Smaller, wing less than 140 mm 2 



2. Throat, a collar on hindneck, and spots on either side of rump clear white. 



Cayenne swift, Panyptila cayennensis cayennensis, p. 244 

 Plumage without clear white markings 3 



3. Rump concolor with crown and back, or nearly so 4 



Rump distinctly lighter colored than crown and back 6 



4. Throat and breast alike in color, end of tail stiff but without prominent 



spines 5 



Throat slightly grayer than breast, end of tail with stiff projecting spines. 

 Chimney swift, Chaetura pelagica, p. 228 



5. Tarsus longer, more than 15 mm.; male and female uniform sooty black 



above, dark grayish brown below. 



Zimmer's swift, Cypseloides cryptus, p. 243 

 Tarsus shorter, less than 13 mm. ; male with rufous-brown collar and fore- 

 neck, female usually plain. 



Chestnut-collared swift, Cypseloides rutilus, p. 240 



6. Upper tail coverts sooty black like crown and back; rump distinctly white, 



forming a prominent band. .Band-rumped swift, Chaetura spinicauda, p. 235 



