Distribution

Figure 1. Distribution of the White-throated Sparrow.

Figure 7. Relative abundance of breeding White-throated Sparrows in the USA and s. Canada, based on BBS data 1994-2003.

The Americas

Breeding Range

Breeds throughout the boreal coniferous and mixed forest south of the tree line, mainly east of the Rocky Mountains (Fig. 1, Fig. 7). Also breeds west of the Rockies in n.-central British Columbia (Campbell et al. 2001). Southern breeding limit in w. Canada generally follows northern limit of aspen parkland, although fragmented populations occur in isolated pockets of coniferous forest just to south. Breeding distribution extends south into Great Lakes forest region of Minnesota, n. Wisconsin, central Michigan, s. New York, and Appalachian Mtn. regions of ne. Pennsylvania, nw. Connecticut, s. New Hampshire, Massachusetts, Rhode Island, and nw. New Jersey (Lowther and Falls 1968).

In NY State, recent records (2005) show center of breeding distribution in Adirondacks, with scattered records into the Catskills and southern tier (http://www.dec.ny.gov/cfmx/extapps/bba/bbaMaps.cfm?bndcode=WTSP&order=2&year=2000&comp=0). In Massachusetts, likewise found breeding mostly in higher elevation regions (Berkshires), with scattered records to east and south (http://www.massaudubon.org/birdatlas/bba1/index.php?search=yes&id=177).

Isolated breeding records in Appalachian Mtns. as far south as West Virginia (Ganier and Buchanan 1953). Non-breeding birds occasionally observed in summer south to Arkansas, Tennessee, and Maryland (Lowther and Falls 1968, DeSante and Pyle 1986). A casual stray to Alaska at any season (Kessel and Gibson 1978) and has strayed in summer as far north as Baffin I. (Godfrey 1986).

Winter Range

Winter populations densest east of Great Plains, lower numbers occurring through southern plains in Oklahoma, Texas, New Mexico, Arizona, and n. Mexico (Root 1988); casual in s. Florida, occasional records in West Indies (Norton 1998) and Bahamas (Lee et al. 1999). Overlaps breeding range in ne. U.S. and se. Canada. Isolated winter records north to Alberta, Manitoba, Quebec, New Brunswick, Newfoundland (Lowther and Falls 1968). Disjunct wintering population in w. California and Oregon, north to sw. British Columbia, where it has increased since the 1960s (Campbell et al. 2001).

Outside The Americas

Commonest vagrant Nearctic sparrow in western palaearctic (Perrins 1994). Scattered records in British Isles, fewer in w. continental Europe (Durand 1961, Dennis 1966, Mikkola 1969, McMorran et al. 1973, Stoffels and van der Weijden 1978, Stansfield 1996, Yorkshire-Birding 2003, Buness and Solbakken 2004).

Historical Changes

A major extension of the breeding range into central British Columbia has occurred since the 1940s and the winter range has extended into sw. British Columbia since the mid 1960s (Campbell et al. 2001). Slight extensions in summer range reported in New York (Anderle and Carroll 1988) and Vermont (Laughlin and Kibbe 1985) and in winter range west of longitude 95o W into se. Great Plains (Root 1988); winter range otherwise limited by precipitation and average minimum Jan temperatures.

Fossil History

Late Pleistocene (Rancholabrean North American Land Mammal Age, from 400,000 years before present) remains from cave deposits at Natural Chimneys, Augusta Co., VA (Wetmore 1962) and Cheek Bend Cave, Maury Co., TN (Parmalee and Klippel 1982). In addition, there is a species of Zonotrichia, most likely Z. albicollis, represented in Rancholabrean fossils from Reddick 1A, FL (R. Chandler pers. obs.).