PICIDJE: WOODPECKEItS. 477 



27. Family PICID-^ : Woodpeckers. 



Feet perfectly zygodactyle by reversion of the 

 fourth toe (iu two genera the first toe wautiug) ; 

 tail-feathers rigid, acuminate; hill a chisel. This 

 expression will serve for the recognition of any 

 woodpecker (cornpare diagnoses of previous Pica- 

 rian tamilies). Wing of 10 primaries, the 1st 

 quite short or even spurious, the wing-formula 

 being quite as in most passerine birds — a crow 

 or thrush, for example. Greater row of second- 

 ary coverts short, as in passerine birds at large. 

 Tail of 12 rectrices, but the outermost pair I'udi- 

 mentary, lying concealed at the base of the tail 



Fig. 328. — European Spotted "Woodpecker (Picus between the penultimate (now exterior) and next 

 major), reduced. (From Dixou.) p.^^^.^ g^ ^j^^^ ^j^^^.^ ^^p^^^. ^^ ^^ ^^^^ ^^^ ^^ ^^^^^^ 



in Picarian birds (a strong peculiarity). Tail-feathers very stiff and strong, with enlarged 

 elastic shafts, and acuminate at the end. Tarsi scutellate in front, on the sides and behind 

 variously reticulate. Toes strongly scutellate on top. The usual ratio of the toes is : 1st 

 (inner posterit)r) shortest ; 2d (inner anterior) next longer ; 3d (outer anterior) longer ; 4tli 

 (outer posterior) longest of aU (in most typical species; in some, however, scarcely or not 

 equalling the 3d in length). The basal joints of the toes are abbreviated. There is a very 

 unusual arrangement of the flexor tendons of the toes (shared, however, among Toucans, 

 Scausorial Barbets, and Jacamars). 



These birds have been specially studied, with more or less gratifying success, by Malherbe, 

 Sundevall and Cassin. There are nearly 250 well determined species, of all parts of the world 

 except Madagascar, Australia, and Polynesia. Their separation into minor groups has not been 

 agreed upon ; our species are commonly thrown into three divisions, which, however, I shall 

 not present, as consideration of exotic forms shows how the genera are inten-elated, and how 

 nice is the gradation in form between the Ivory-bill and the Flicker, which stand nearly at 

 extremes of the family; the little diversity of which is thereby evident. One of our genera, 

 without very obvious external peculiarities, stands apart from the rest in the character of the 

 t(jngue. In ordinary Pici the " horns " of the tongue are extraordinarily produced backward, 

 as slender jointed bony rods curling up over the skuU behind, between the skin and the bone, 

 to the eyes or even further ; these rods are enwrapped in highly developed, specialized muscles 

 by means of which the birds thrust out the tongue sometimes several iuches beyond the bill 

 (figs. 73, 74). This is not the case in Sphyropicus, where the hyoid cornua do not extend beyond 

 the base of the skull, and the tongue, consequently, is but little more extensible than in ordinary 

 birds. The tongue of Sphyropicus is beset at the end by numerous brushy filameuts, instead of 

 the few acute barbs connnonly observed in the family. The same or a similar condition of the 

 parts is observed in Xenopicus. In most of our species the bill is perfectly straight, wide and 

 stout at the base, tapering regularly to a compressed and veitically truncate tip, chisel-like, and 

 strengthened by sharp ridges on the side of the upper mandible — an admirable tool for cutting 

 into trees; and in all such, the nostrils are hidden by dense tufts of antrorse feathers. In 

 others, like the Flicker, the bill is smooth and barely curved ; the tip is acute and the nostrils 

 are exposed. There is a regular gradation in form between those with the most and the least 

 chisel-like bills. The former are more stocky-bodied birds, with larger heads in comparison 

 with the constricted neck, as any one may satisfy himself by skinning a Pileated or Hairy 

 Woodpecker, and trying to pull the skin over the head — an operation which may be performed 

 on a Flicker. The ridges of the bill, the bevelling of the end, the nasal tufts, and usually the 



