Clay-colored Sparrow x Field Sparrow hybrid, Grand Isle, Lake Champlin (Vermont, USA), May and July 1998 - copyright Dave Hoag
(photo ID: 1801)
Vermont is outside of the normal range for Clay-colored Sparrow but Dave sound-recorded a singing bird on Grand Isle between 29th May and 5th June 1997. On 23rd July he recorded a second bird, but while this one shared the buzzy quality of Clay-colored Sparrow its song pattern, with added trill at the end, more closely resembled Field Sparrow. Its plumage was intermediate too, ruling out any possibility that it was a Field Sparrow that had learned Clay-colored song. Moreover Dave tells us that by August its face pattern remained different from Clay-colored Sparrow (not sharply defined as on worn adult Clay-colored), eliminating any chance that it was a Clay-colored Sparrow that had learned Field Sparrow song (also its bill was pink).
This bird returned in the summers of 1998 and 1999 when it was paired with a female Field Sparrow, and they raised 2-3 young successfully in 1999.
The Vermont Birds Records Committee concurred with Dave's identification and in 1999 the occurrence was published in Wilson Bulletin 111 (4): 581-584 along with sonograms of the bird's song.
Clay-colored Sparrow Spizella pallida
Field Sparrow Spizella pusilla