A Nesting of the Slaty Antshrike (Thamnophilus punctatus) on Barro Colorado Island

Abstract

TWENTY-ONE species of Antbirds (Formicariidae) occur within the limits of the Panama Canal Zone. They are gifted neither with bright plumage nor with beautiful songs, but despite these deficiencies many are birds of distinct personality whose acquaintance is well worth the pains to cultivate it-and these are not inconsiderable, for most are shy and retiring inhabitants of the heavy forest or the dense, impenetrable second growth thickets. Clad in black and white, or shades of brown, olive or gray, a number of species are further ornamented by areas of brightly colored bare skin on the cheeks or crown. Although they are not true song birds, the calls of some are pleasing and melodious, and range in character from the cosy little trill of the Tyrannine Antbird (Cercomacra tyrannina) to the full, mellow triple whistle of the Panama Antthrush (Formicarius analis). In habits they are equally diverse, for some, like the Antwren (Microrhopias quixensis) live among the trees and have the mannerisms of an active Warbler, while at the other extreme we have the Antthrush just mentioned, which is entirely terrestrial, and treads with the dainty gait of a Rail the dry leaves of the forest floor, with whose color it blends remarkably well. Our bird is intermediate between these two extreme types in its mode of feeding and the level of the forest at which it prefers to live. The Slaty Antshrike (Thamnophilu punctatus atrinuchus Salvin and Godman) is happy in its generic name, for it loves the low bushes which grow beneath the lofty canopy of the lighter forests. Scarcely larger than a Chipping Sparrow, the male is blackish slate-color above and grayish slate below, the secondaries margined and the rectrices tipped with white (Plate III, fig. 2). His mate is olive brown above and buffy olive below, with chestnut