Nelson's Sparrow (Ammospiza nelsoni) [XC664089]
by Paul Driver from Mount Desert Island (near Southwest Harbor), Hancock County, Maine, United States (song)
Nelson's Sparrow (Ammospiza nelsoni) [XC420481]
by Will Sweet from Tijuana Slough National Wildlife Refuge visitor center, Imperial Beach, San Diego County, California, United States (call)
Subspecies
Ammodramus caudacutus (Sibley and Monroe 1990, 1993) has been split into Sharp-tailed Sparrow (Ammospiza caudacuta) and Nelson's Sparrow (Ammospiza nelsoni) following AOU (1998).
Genus, as currently delimited, is probably polyphyletic. Molecular studies suggest that present species is in a clade with Seaside Sparrow (Ammospiza maritima), Sharp-tailed Sparrow (Ammospiza caudacuta) and Le Conte's Sparrow (Ammospiza leconteii). Has hybridized with Le Conte's Sparrow (Ammospiza leconteii). Until recently considered conspecific with Sharp-tailed Sparrow (Ammospiza caudacuta), but differs in its natural history. The two hybridize in north-eastern USA (southern Maine and northern Massachusetts). Precise ranges of the two on Atlantic coast not fully known, as references to "Sharp-tailed Sparrow" not always clear. Distinctive subspecies subvirgatus perhaps represents a distinct species. Further study is needed. Subspecies alter poorly differentiated from nominate.
The following 3 subspecies are recognised:
nelsoni Allen, 1875 - Breeds in Canada from north-eastern British Columbia and southern Mackenzie Seast through Alberta to central and southern Saskatchewan and central Manitoba, and in northern USA in north, western and south-eastern North Dakota, north-eastern South Dakota and north-western Minnesota. Winters on Pacific coast of south-western USA (California) and in extreme north-western Mexico (northern Baja California) and on Gulf Coast from Texas east to Florida Panhandle, also rarely south to Tamaulipas (north-eastern Mexico).
alter (Todd, 1938) - Breeds in east-central Canada from northern Manitoba east to northern Ontario and western Quebec; probably winters on Gulf Coast of USA (west to Texas).
subvirgatus Dwight, 1887 - Breeds in south-eastern Canada (southern side of St Lawrence R in southern Quebec east to New Brunswick, Prince Edward I and Nova Scotia), and in north-eastern USA south to southern Maine and northern Massachusetts. Non-breeding on Atlantic coast south to South Carolina and northern Florida, casually north to New York.
BirdLife International Species Factsheet