FAMILY FALCONIDAE 



261 



Resident. Throughout the tropical zone, locally common, but 

 in recent years rare or absent from the more heavily settled regions 

 (including the Canal Zone) ; ranging to 1280 meters in the lower 

 subtropical zone (Palo Santo, El Volcan) on the Pacific slope in 

 Chiriqui. 



The strange calls of this interesting species of the falcon family 

 are the usual indication of its presence, as the birds themselves may 

 be seen infrequently, especially in heavily forested areas. Though 



Fig. 47. — Laughing falcon, vaquero, Herpetotheres cachinnans cachinnans. 



they are not particularly wary, it is usual for them to rest on 

 high, open perches that many times are concealed from observation 

 by leafy cover below. At rest they stand erect, the bushy crest 

 causing the head to appear large. During flight the short, rounded 

 wings, which beat rapidly, and the long tail present an unusual 

 silhouette. The loud calls, heard most often in morning and eve- 

 ning, as well as through the night, in still air carry distances of 

 more than a kilometer. They begin with a single note, repeated 

 rather slowly, increase in tempo, and change to a loud gua kow, 

 uttered more and more rapidly. Presently a companion may join 

 when the two may call, sometimes alternately, sometimes in unison, 

 for 10 minutes or more, a strange, weird concert, startling to one 



