380 BLACK-BACKED THREE-TOED WOODPECKER. 



Nestling mak. Siniilnr to tlie adult but with the yellow on the heail more restricted nnd the black on the back is dull- 

 er, while a few feathers in the interscapular region are spotted with white. 



Nestling female. Similar to tlic adult but, singularly, the top of the head is spotted with yellow. Descriptions of the 

 In-st two ])lur.iaocs are from specimens in the collection of Mr Brewster. Iris, brown, bill, black, bluish at base of lower 

 niundihh-, nnd fact, l)lui.--h, in all stages. 



OllSERVATIONS. 

 There is more black spotting below in some s))eeimcns than in others hut they are generally quite uniform in color. 

 I'cadily known from other Woodpeckers by the absence of any red on the head vvhicli is replaced hy yellow. Ivnown from the 

 succeeding species, by the absence of the transTorse white l)andings above. Distributed, as aconstaut resident, through- 

 oat North America from the latitude of IMaiue to t!ie Arctic Circle. 



DIMENSIONS. 



Averngc measurciiients of specimens from the North. Length, i)-50: stretch, l.'i 50; wing, .5(10; tail, ."i'TO; bill. rG.'i; 

 tarsus, -70. Longest s])ceimen, lO-OO; greatest extent (.f wing, IC'OO; longest wing, ^)'50: tail, 382, hill, i:!0; tarsus, -T.^. 

 Shortest specimen, 9-00; smallest extent of wing, IS'dl); shv^rtest wing, 4'.50; tail, 3-75; bill, I'^O; tarsus, -0.5. 



DESCRirTION OF NESTS AND EOOS. 



A'csAs, placed in cylinder-sliaped holes, generally excavated in living trees. Dimensiuns, diameter of external orilice, 

 1'50, gretitest internal, S'OO. Internal depth, IS'OO. 



E^:t;s, four to six in number, rather ovate in f /lui, ])urc, ]]olished pearly-white in color. Duncnsions from 'OOx '75 to 

 05 X -Si I. 



HABITS. 



The mere mention of the Three-toed Woodpeckers recalls to my mind the snow-clad 

 monntains and dark evei'green forests of Nortliern New England, for it was among tliein, 

 that I first became acquainted with tht^se singular birds. The Black-backed Three-toed 

 Woodpeckers appear to be quite unconnnon, even in winter, in these boreal climes, wlicro 

 the sharp cries of the Downy and Hairy are quite frequently heard and, occasionally, the 

 louder notes of the Piletited greets the ear, but one may travel for da3's, over snow-covered 

 ground, beneath the frozen branches of the pines and spruces, without hearing the discor- 

 dant sounds produced by this rare Woodpecker. 



These Woodpeckers, like many other members of the family, arc only migratory to a 

 limited extent; thus, during unusually severe winters, they may occasionally reach Mass- 

 achusetts in their southward flight, but they arc exceedingly rare and I know of but two 

 or three instances on record of their having been taken here. These Woodpeckers agree 

 in general habits quite closely with the members of the preceding genus; their flight is 

 simikir and in climbing, they are as expert as any of the other Woodpeckers; three toes on 

 each foot appearing to answer as well for clinging to the bark as four. It is dillicult to ac- 

 count for the absence of the hind toe as this apparent mutilation does not impede the move- 

 ments of the binls in the least, yet it is, porh;;ps, .singular that wc do n(;t f:nd lacro sisecicr, 

 without it, for, as a rule, any Si!p?rfl-,'.if7 ia nr.tan", n')t orniimcntrd; i^ .-diaor.t invnrinhly 

 discarded. 



The nesting habits of this raie species of Woodpecker are not well known but they 

 are said to build in living trees, idobably about the same time as the Hairy or Downy. 

 They are a little more northern in distribution during the breeding season than the suc- 

 ceeding species. 



