YELLOW-BILLED CUCKOO 



cc. General color of plumage chestnut; bill strongly 

 decurved at tip. 



d. Larger, length, 421 mm. (16.50 in.) 



Piaya cayana thermophila 



dd. Smaller, length, 257 mm. (10.10 in.) 



Coccycua rutila panamensis 



bb. Head crested. 



c. Very large, length, 488 mm. (19.15 in.); upper 

 parts (olive or purplish brown) without dis- 

 tinctive markings; crest blue-black; a band of 

 black spots across breast. . .Neomorphus salvini 



cc. Smaller, length, 373 mm. (14.70 in.) or less; crest 

 not blue-black; upper parts with distinctive 

 markings. 



d. Upper part buffy brown and (including reddish 

 brown crest) streaked with black ; tail feathers 



narrow and tipped with reddish buff 



Tapera ncevia excellens 



dd. Upper parts dusky brown and excepting crest 

 feathers tipped with whitish; tail feathers 



very broad and tipped with white 



Dromococcyx phasianellus 



aa. Coloration black; bill excessively deep, compressed and 

 arched. 



b. Larger, length, about 458 mm. (18.00 in.); glossy 

 blue-black Crotophaga major 



bb. Smaller, length, 360 mm. (14.20 in.) or less; duller 

 black. 



c. Sides of upper mandible with several curved 



grooves parallel with ridge 



Crotophaga sulcirostris 



cc. Sides of upper mandible smooth. . . Crotophaga ani 



i. Coccyzus americanus americanus (Linnaeus) 

 Yellow-billed Cuckoo 



Sexes alike. Length, 280 mm. (n.oo in.); 

 tail, 143 mm. (5.60 in.). Above smooth grayish 

 brown, outer webs of primary wing feathers ru- 

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