All feature a messy central breast spot though it is less noticeable on the thick billed and slate-colored varieties.

Fox sparrows nest in wooded areas across northern Canada and western North America from Alaska to California.

A nest typically contains two to five pale green to greenish white eggs speckled with reddish brown.

[5] The review by Zink & Weckstein (2003),[6] which added mtDNA cytochrome b, NADH dehydrogenase subunit 2 and 3, and D-loop sequence, confirmed the four "subspecies groups"[7] of the fox sparrow that were outlined by the initial limited mtDNA haplotype comparison (Zink 1994).

[6] Biogeography indicates that the coastal populations were probably isolated during an epoch of glaciation of the Rocky Mountains range, but this is also not very helpful in resolving the remaining problems of within-group diversity, and inter-group relationships.