Impressions of the Voices of Tropical Birds 



By LOUIS AGASSIZ FUERTES 



Illustrated by the author , 



THIRD PAPER— ORIOLES, FLYCATCHERS, FINCHES, AND THRUSHES 



A COMPARATIVE study of the notes and songs of the birds of the 

 tropics and their familiar northern representatives is certainly not 

 less interesting than the study of their physical resemblances and 

 differences. And here it may be suggested that resemblances, which are of 

 greatest value as showing relationships, are even more elusive and hard to 

 follow out than are more physical characters. Differences are of negative 

 importance; resemblances alone count in tracing racial aflfinities. 



In this respect the great family of tropical Orioles hangs together as a 

 unit, and ties closely to its more familiar northern offshoots. From the tiny 

 Mexican Orchard Oriole to the crow-sized Oropendolas, there is some subtle 

 quirk of tone that makes them all recognizable to anyone having a single 

 good acquaintance in the family. 



I think no birds in tropical America have given me more pure fun with 

 their vocal performances than the big Yellowtails, or Oropendolas; Gymnos- 

 tinops in southern Mexico, and the various species of Ostinops in Colombia. I 

 cannot now remember any striking differences in their songs or calls, except 

 that Gymnostinops combines more gymnastics with his efifort than mere 

 Ostinops. But everywhere in tropical America the loud rasps, chucks, and 

 gurglings of these great Orioles are as characteristic as the steady flashing of 

 black and gold in the burning sky, as they wing over head from bank to bank 

 of the great rivers. 



They are all highly polygamous, and I have frequently seen them demon- 

 strate a most watchful and efficient warden-service in favor of the old males. 

 After one shot, you may stalk and stalk the big black Sultan, "quisking" 

 from the bare dead spike above the forest roof, only to be defeated, time after 

 time, by the party of six or eight silent and watchful females perching around 

 him at lower points. Silent, that is, until you get within about twice gunshot 

 of their lord, when they suddenly squawk and yell, and the old boss "yips" 

 loudly and, with batting wings, leaves for foreign parts. 



The calls of the male, given from a high perch with a commanding view, 

 may be variously described: a loud, vigorous "quisk," — an equally carrying 

 but very liquid "churg," ending inside an empty cask, — a series of dry, ascend- 

 ing clicks or twig-snaps, probably done with the enormously strong and hol- 

 lowed bill. But his true song, to call it so, defies description or imitation with- 

 out all the "traps" of the triangle-man in the orchestra. Imagine a perform- 

 ance lasting only about two seconds, commenced by breaking off a handful of 

 willow sticks, then running into a rising series of "choog-choog-choogs," to 

 end in a loud, explosive "keow," easily audible at a quarter of a mile. This 



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