Just a further note to anyone interested in previous hybrids between
Golden-crowned and White-throated Sparrows, the reference given in the
recent "The Birds of N. America" monograph on White-throated Sparrow is:

Payne, R. A. 1979. Two apparent hybrid _Zonotrichia_ sparrows.
Auk 96: 595-599.

The monograph for Golden-crowned Sparrow has not yet been published but
I will update here if it contains any other references.

- Jack


Jack Bowling
Prince George, BC
CANADA
jcbowling at mindlink.bc.ca