200 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



to Ridgway, who described them as southern subspecific representa- 

 tives of the better-known and more widely distributed gray-cheeked 

 thrush. Subsequent explorations soon disclosed the presence of the 

 thrush on the nearby mountains of New England, causing ornitholo- 

 gists of that period to express both surprise and chagrin that the 

 existence of a bird regularly breeding in the Northeastern States 

 should have gone so long undetected. 



Aside from its very scattered and restricted distribution in the 

 Canadian Maritime Provinces, Bicknell's thrush proved to be a strictly 

 montane form, limited in the breeding season to high elevations in the 

 mountains of New England and eastern New York. It belongs 

 primarily in the ecological niche extending from the 3,000-foot level 

 up to timberline, in an environment of dense, stunted evergreens, 

 where the rocky fir-clad heights are almost perpetually bathed in mists 

 and clouds. 



Because of the Bicknell's occupation of such a limited zone in only 

 the most isolated regions, and because of its habit of nesting in the 

 most inaccessible parts of these remote areas, the bird has long re- 

 mained in comparative obscurity, its taxonomy and nomenclature 

 confused, its distribution incompletely or erroneously recorded, its 

 life history and ecology but little known. Excursions into its breeding 

 haunts revealed many interesting but rather fragmentary and some- 

 times conflicting bits of information that at best were an inadequate 

 record of the haunts and habits of the thrush. In 1935, however, the 

 present writer had an opportunity to follow the bird through one com- 

 plete breeding cycle, thus making it possible to clear up some of the 

 obscure features regarding this interesting thrush. 



Spring. — Bicknell's thrushes appear in the United States early in 

 May, at which time they reach the southern Atlantic States from their 

 west Indian winter home (the first continental spring records sub- 

 stantiated by specimens are for Charleston, S. C, on May 2, and the 

 north Floridian coast on May 3). From there they move northward 

 along the coast, passing through Washington, D. C, about the middle 

 of May and arriving in southern New England during the latter half 

 of the month (18 of the New England specimens were taken between 

 the 20th and 30th of May, 5 earlier than the 20th, and 1 as late as 

 June 11). During this period also they gradually move up into the 

 mountains, presumably as soon as the retreating snows permit. They 

 have been found returning to Mount Moosilauke in New Hampshire 

 between the 25th and 30th of May (G. M. Allen, 1902), have been 

 reported for Mount Mansfield, Vt., on May 25 (Davenport, unpub- 

 lished bird list), and for Mount Greylock, Mass., between May 28 

 and 30 (Maynard, 1910). In 1935, in a considerably retarded spring, 

 only a few were found in the snow-bound summit of Mount Mans- 



