Friday, September 27, 2013
Distinguishing Hairy and Downy Woodpeckers
One identification challenge that is commonly faced by birders in southeast Louisiana is that of separating Hairy and Downy Woodpeckers. Apart from barring on the outer tail feathers of the Downy (white in Hairy), there is no simple mark that can be used to separate the species- only more subjective characters of size, bill size, and voice.
The following should provide additional help:
1) Relative abundance
in our area overall, Downies greatly outnumber Hairies. In urban New Orleans, the ratio is greater than 100:1. In non-urban forested areas, it is not so lop-sided, but Downy is still notably more numerous than Hairy. So keep in mind that the odds are with Downy from the start.
I probably detect a half dozen or fewer Hairies per year in urban New Orleans (this includes one this morning in the Jefferson batture, which prompted this post!). However, in forests outside town, they are regular enough that it is reasonable to hope for one on a given day's list.
2) Bill size
Hairy bills really are noticeably larger than Downies- enough so that an observer familiar with both can know immediately which one they are looking at. A Hairy bill looks like a chisel, a Downy like a pick.
3) Call note
Although the pik of the Downy and peek of the Hairy may seem (from these descriptions) quite similar, these are again different enough that an observer familiar with them can separate them with confidence, even a single note heard at a distance. The Hairy note is louder and more robust.
The long calls of the species are not confusable- the Downy being a trailing-off series of rather delicate notes, and the Hairy being a loud evenly pitched rattle- maybe even more like a kingfisher than a Downy.
A little publicized difference is the length of the drum roll- Hairy notably longer, with (in my experience) little or no overlap in length. However, it is rare to have opportunity to use this.
4) Body size
Again, the species differ enough that this difference will often make the species identity obvious to an experienced observer immediately. Even flying across an opening.
Go out and find a Hairy!