JO^ 



PODICiriD^, GREBES. 335 



^ Var. PACiFicus. Colors the same ; size less ; length about 2 feet ; wing about 

 11; tarsus 2i ; bill 2-2|, very weak and slender. Northwestern Am., abundant 

 on the Pacific Coast of the U. S. in winter. Lawr. in Bd., 889 ; Coues, I. c. 228. 

 l^ ^, I Ited-tJiroated Diver. Blackish ; below white, dark along the sides and on 

 the vent and crissum ; most of head and fore neck bluish-gray, the throat 

 with a large cliestnut patch ; hind neck sharply streaked with white on a 

 blackish ground ; bill black. Young have not these marks on the head and 

 neck, but a profusion of small, sharp, circular or oval white spots on the back. 

 Size of the last, or rather less. N. Am. and N. Europe, comuion ; dispersed 

 over most of the U. S. in winter. Sav. and Rich., F. B.-A. ii, 476 ; Nutt., 

 ii, 519 ; Aud., vii, 299, pi. 478 ; Lawi^. in Be, 890.. septentkionalis. 



Family PODICIPID.S]. Grebes. 



Bill of much the same character as that of loons, but generally weaker, in one 

 genus only quite stout and somewhat hooked. Nostrils linear, linear-oblong or 

 oval, not lobed. Head incompletely feathered, with definitely nalced lores, the 

 feathers not reaching the nostrils ; commonly adorned in the breeding season with 

 lengthened gaylj'-colored crests, rnffs, or ear-tufts. Back not spotted ; under 

 plumage peculiarly silky and lustrous, usually white. Wings very short and con- 

 cave, the primaries often attenuated at the end, covered by the large inner quills 

 when closed. Tail a mere tuft of downy feathers, without perfectly formed rectrices. 

 Feet lobate, the front toes also semipalmate ; tarsi compressed, scutellate, their 

 hinder edge rough with a double row of protuberant scales ; toes flattened ; claws 

 short, broad, flat, obtuse, something like human nails. 



The grebes are strongly marked by the foregoing characters, especially of the 

 feet and tail, though they agree closely with the loons in general structure and 

 economy. Principal internal characters are the absence, it is said, of one carotid, 

 the greater number of cervical vertebrae (19 instead of 13) and shortness of the 

 sternum, with lateral processes reaching beyond the transverse main part (the 

 reverse of the case in loons). The gizzard has a special pyloric sac. These birds 

 are expert divers, and have the curious habit of sinking back quietly into the water 

 when alarmed, like anhingas. Owing to the virtual absence of the tail the general 

 aspect is singular, rendered still more so bj^ the almost grotesque parti-colored rutFs 

 and crests that most species possess. These ornaments are very transient ; old 

 birds in winter, and the young, are very diflTerent from the adults in breeding attire. 

 The eggs are more numerous than in other pj-gopodous birds, frequently numberiug 

 6-8 ; elliptical, of a pale or whitish color, unvariegated ; commonly covered with 

 chalky substance. The nest is formed of matted vegetation, close to the water, or 

 even, it is said, floating among aquatic plants ; the young swim directly. Grebes 

 are the only cosmopolitan birds of the order, being abundantlj^ distributed over the 

 lakes and rivers of all parts of the world, though they are less maritime than 

 the species of either of the other families. There are not over twenty well deter- 

 mined species, for which fifteen generic, and about seventy specific, names are 

 recorded. The genera requiring recognition are only two. In Podilymbus, the hill 

 is short, stout, and bent at the end, the lores are broadly naked, the frontal feathers 

 are bristly and there are no ruffs or crests ; in all the rest of the grebes the bill is 

 slender, straight and more or less acutely paragnathous, the naked loral strip 

 is narrow, and the soft feathers of the head form lengthened tufts of various kinds. 



