Date: 12/31/17 11:12 am From: John Jones <johnjonesbirder...> Subject: [cobirds] Wintering Marsh Wrens along the Front Range
I was walking along the Platte River the other day and had a wintering Marsh Wren there, which surprised me, though I know they winter along the Front Range. This got me thinking about the Eastern vs Western versions of Marsh Wren, and whether the bird I saw is more likely to be one than the other. Unfortunately, it didn't sing, and I didn't see it well, so I can't get to a subspecies ID on the bird I saw. In googling around, I found this great article (link below) by Tony Leukering and Nathan Pieplow, which was written in 2010. They say that during the breeding season, all our birds are Western Marsh Wren. However, they, and one of their sources, note that "northern form *iliacus *and the eastern *dissaeptus* should occur in eastern counties in winter or during migration."
So, what have we learned since then? Has anyone had an Eastern Marsh Wren along the Front Range in the winter? Is it safe to assume all the wintering Marsh Wrens are Western?