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Downy Woodpecker: Variable? Hybrid? - Printable Version

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Downy Woodpecker: Variable? Hybrid? - tshedwall - 19 Sep 2018

I saw a Downy woodpecker at Kachina Wetlands on 9-8-2018 and again today (9-19-2018.) I'm not certain it is the same bird, but they both show a dark vertical line in front of the eye as well as some other similarities. The bird on the tree is from 9-8-2018, while the bird on the mullein is from 9-19-2018. Both birds were small, with spotting on the tail. The mullein bird called a few times and sounded like a Downy to me.

On the tree bird, I noticed that the pale band around the back of the head was broken by a dark line, which according to Sibley, is more likely on a Hairy Woodpecker. I couldn't figure out how common that is on a Downy, but I did find a hybrid rabbit hole to wander into. This article by Steve Mlodinow seems to be the only write up of a Downy x Hairy Hybrid:
https://www.westernfieldornithologists.org/archive/V46/46(1)-p002-p007.pdf

His discussion of bill proportion vs. nasal bristle length and vs. head length suggests that this bird's bill is out of range of a normal Downy, perhaps particularly for a female. It also shows a shoulder spur that seems a bit long for a Downy-- faint at one angle and obvious at another.

I decided to let it go until I saw this (possibly same) bird today. The pale band is kind of messy, not as obviously broken as on the earlier bird. It also seems to only show the shoulder spur on the bird's left side, with nothing visible on the right side.

Mlodinow mentions that hybrid woodpeckers aren't terribly unusual and suspects that Downy X Hairy might just be overlooked rather than rare.

Any thoughts?

9-8 Bird:
[attachment=19829][attachment=19830]

9-19 Bird:
[attachment=19831][attachment=19832][attachment=19833]


RE: Downy Woodpecker: Variable? Hybrid? - BrianHof - 19 Sep 2018

Out of curiosity, could you get any impression of size? I know an intermediate size doesn't necessarily indicate a hybrid, but it could provide some clues?

Brian H.


RE: Downy Woodpecker: Variable? Hybrid? - tshedwall - 19 Sep 2018

Brian, I only noticed that it was obviously smaller than a Hairy. I don't see Downys often enough to have an opinion on whether it was normal sized. I suppose I could put a measuring tape on that tree (it was right near the entrance) or on a mullein to get an idea.


RE: Downy Woodpecker: Variable? Hybrid? - tshedwall - 20 Sep 2018

I measured some mullein in the neighborhood and got about 35 overlapping rows of flower buds per foot, which puts my bird in the 6 to 7 inch range.


RE: Downy Woodpecker: Variable? Hybrid? - BrianHof - 21 Sep 2018

(20 Sep 2018, 7:48 AM)tshedwall Wrote: I measured some mullein in the neighborhood and got about 35 overlapping rows of flower buds per foot, which puts my bird in the 6 to 7 inch range.

According to Sibley, the Downy's length is about 6.75 inches, so the size of this bird definitely leans toward Downy. Thanks! This is an intriguing find!