kylealdinger's Identifications

Hybrid phenotype but not typical of either names hybrid. The first 6 pictures and the next 3 pictures may or may not be of the same individual. Recording of it singing a Blue-winged Warbler-type song with OVEN (and maybe other birds) in the background (although if separate individuals, the song corresponds to the bird in the first 6 pics). I hope that all made sense.

Under the powerlines. Bird seen once in a small tree, singing diffidently from among the leaves. Flew to the south, and relocated - although possibility that this second bird was different. Then audaciously perched on powerlines giving bee-buzz song.

Black mask, black throat, yellow crown, yellow wing-bars, white belly with some yellow wash. Long black bill, pink roof of the mouth visible while singing (cool!).

This GWWA had a slight yellow wash to the breast, which means that it phenotypically displays some of its hybridization. However, a study of Golden-winged Warblers in nine different states and territories found that there is only one small population of pure Golden-winged Warblers, in northern Manitoba - but this study did not collect any samples from New England, and only six birds from Quebec (Vallender et al., 2009). Conjecturally, it's likely that there are few or no pure Golden-winged Warblers in New England, as the BWWA range here overlaps that of Golden-Winged Warblers extensively (Toews et al., 2016). This doesn't mean that Golden-winged Warblers are necessarily disappearing due to hybridization - the best model for the data shows several millennia of continuous gene admixture, with only some slight recent anthropogenic genetic admixture (Toews et al., 2016).

This bird I believed has been identified before at Colchester pond, and I've found pictures of it both identified as a hybrid Golden- x Blue-winged warbler, and as a pure Golden-winged Warbler. I would argue that labeling it as a GWWA based on the majority of the field-marks matching GWWA makes more sense than labeling it as a hybrid and only looking at phenotypical features. It is known that hybrids may be cryptic phenotypically.

More subjectively, as this is my lifer bird, adding it here as a GWWA.

• Toews, D. P., Taylor, S. A., Vallender, R., Brelsford, A., Butcher, B. G., Messer, P. W., & Lovette, I. J. (2016). Plumage genes and little else distinguish the genomes of hybridizing warblers. Current Biology, 26(17), 2313-2318.
• Vallender, R., Van Wilgenburg, S., Bulluck, L., Roth, A., Canterbury, R., Larkin, J., ... & Lovette, I. (2009). Extensive rangewide mitochondrial introgression indicates substantial cryptic hybridization in the Golden-winged Warbler (Vermivora chrysoptera). Avian Conservation and Ecology, 4(2).