A couple of years ago, Al Jaramillo asked about the incidence of
hybridization among the larger members of the Zonotrichia genus
of Nearctic sparrows, specifically between Golden-crowned,
White-throated, and White-crowned Sparrows.

I received the monograph on the Golden-crowned Sparrow
_Zonotrichia atricapilla_ in the current ongoing series being
published by the Birds of North America Inc., Philadelphia, PA
entitled "The Birds of North America". Therein lie several
references:

White-crowned x Golden-crowned:

1) Miller, A. H. 1940. A hybrid between Zonotrichia coronata and
Zonotrichia leucophrys. Condor 42:45-48.
2) Morton, M. L., and L.R. Mewaldt 1960. Further evidence of
hybridization between Zonotrichia atricapilla and Zonotrichia
leucophrys. Condor 62:485-486.
3) Wahl, T.R. 1995. The Birds of Whatcom County: status and
distribution. (Privately published by T.R. Wahl, Bellingham, WA;
printed by The Print Shop, Lyden, WA).

White-throated x Golden-crowned:

1) Payne, R. B. 1979. Two apparent hybrid Zonotrichia sparrows.
Auk 96:595-599.
2) Wahl, T.R. 1995. The Birds of Whatcom County: status and
distribution. (Privately published by T.R. Wahl, Bellingham, WA;
printed by The Print Shop, Lyden, WA).

The work states that the latter cross is rarer than the first
which makes sense given the extremely limited contact zone of
the two species during the breeding season.

- Jack
---------------------------
Jack Bowling
Prince George, BC
jbowling at direct.ca