1926] Swarth: Birds and Mammals from the Atlin Region 123

I am using the binomial name for this bird in the conviction that
the three white-crowned sparrows, leucophrys, gambelu, and nuttalli
are three distinct species. There are various trenchant external char-
acters of plumage and other parts distinguishing them, there are just

Maes

L

INLLN.

Bao s
ile

hy
br

tgiee #e

| NORTH AMERICA

(STATE BOUNDARIES)

SCALE OF mikes

— Ee
-30 0 00300500700

Fig. J. Map showing breeding ranges, approximately outlined, of (1) Zonotrichia
leucophrys, (2) Zonotrichia gambelii, and (3) Zonotrichia nuttalli.

as notable differences of song, and the breeding ranges and migration
routes also are indicative of specific differences (see fig. J). As regards
external characters, while I am aware that there are various published
statements of the existence of intergradation between these forms, these