466 Annals of the Carnegie Museum. 



156. Spizaetus tyrannus (Neuwied). 



Falco tyrannus Neuwiee, Reise n. Bras., I, 1820, 360; Teram. PI. Col., 73. 



Spizaetus tyrannus Lawrence, Ann. Lye. N. Y., IX, 1868, 132 (Tucurriqui 

 [Arce, Coll. O. Salvin]). — Frantzius, Jour, fiir Orn., 1869, 368 (C. R. ). — 

 Sharpe, Cat. Birds Brit. Mus., I, 1874, 264. — Zeledon, An Mus. Nac. de 

 C. R., I, 1887, 126. — Salvin and Godman, Biol. Centr.-Am., Aves, III, 

 1901, 93 (San Jose [Underwood]). 



Field Museum : Juan Vinas (Carriker). 



Carnegie Museum : Boruca (Carriker). One skin. 



The present species occupies about the same range as the preceding, 

 but is a much rarer bird, very few specimens of it having been taken 

 in Costa Rica. I secured one specimen at Juan Vinas and one at 

 Boruca, both being shot in rather open woodland. Both birds were 

 quite low down in the trees, and did not seem very shy. 



157. Herpetotheres cachinnans (Linnaeus). 



(Native name " Guaco." ) 



Falco cachinnans Linn^US, Svst. Nat., ed. 12, I, 1766, 128. 



Herpetotheres cachinnans Vieii.LOT, Nouv. Diet. d'Hist. Nat., XVIII, 1817, 

 317. — Lawrence, Ann. Lye. N. Y., IX, 1868, 132 (C. R. [Frantzius]). — 

 Frantzius, Jour, fiir Orn., 1869, 367 (C. R. ). — Ridgway, Bull. U. S. 

 Geol. and Geogr. Surv., 1876, I, 138 (Talamanca [Gabb]). — Sharpe, Cat. 

 Birds Brit. Mus., I, 1874, 278. — Salvin and Godman, Biol. Centr.-Am., 

 Aves, III, 1901, 112 (Bebedero and Miravalles [Underwood]). 



Carnegie Museum: Guacimo, Rio Sicsola, El Hogar (Carriker). 



Three skins. 



Distributed over both the Caribbean and Pacific lowlands, but does 

 not get very high, not more than to 2,000 feet. They frequent almost 

 entirely the forests or wooded pastures, and are always more abundant 

 in districts where snakes are plentiful, for their food consists almost 

 entirely of these reptiles. They have a very peculiar loud cry, which 

 they often utter just before dusk for tenor fifteen minutes with scarcely an 

 intermission. They begin with a call resembling "gua-co " (gwa'-co), 

 slowly at first, with quite a noticeable interval between the two syllables. 

 Gradually the notes increase in rapidity of utterance, while the inter- 

 val between the two syllables decreases, until the call becomes merely 

 a rapid repetition of " guas, guas." In Costa Rica the natives call the 

 bird " Guaco " and in Nicaragua " Guas." 



