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March 23rd, 2014
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How to... Identify a Distant Male Black-capped Gnatcatcher

Black-capped Gnatcatcher is a rare bird in the USA, only found in a handful of mid-elevation canyons in southeastern Arizona, and far from regularly. I got to see a pair of them today, in Florida Canyon. It was only my second sighting of the year, and my first in Florida Canyon in a dozen or so visits. But I’m lucky to see them a few times each year, in the Santa Rita Mountains at Florida Canyon, Montosa Canyon and the lower part of Madera Canyon (Proctor Road area), plus Patagonia Lake State Park, Rock Corral Canyon in the Tumacacori Mountains, and California Gulch in the Atascosa Mountains.

I located them today by first hearing the call, which is just about diagnostic – as long as you’re sure about what you heard, and you’re familiar with the calls of Black-capped, Black-tailed and Blue-gray Gnatcatchers, all of which are possible in this habitat. Black-capped calls tend to be very buzzy (even more so than Blue-gray) with the note sometimes (but not always) rising and then falling, unlike the other gnatcatchers found in the region. It was just such a call that told me I was looking for Black-capped Gnatcatchers today, before they even came into view. By comparison, Black-tailed calls are dryer, more ‘pishy’ than buzzy, and can sound a little less ‘excited’.

Just for a bit of fun, the less-than-ideal views and poor photos I got of today’s male gave me an idea. Here’s a scenario in which you can identify a distant, non-calling Black-capped Gnatcatcher without seeing the all-important undertail… as long as it’s a breeding-plumaged male! Silent female and non-breeding male gnatcatchers always require close views and careful scrutiny to clinch the ID, whereas a reasonably distant or brief Black-capped Gnatcatcher with an actual black cap, while still not easy, should cause you fewer headaches.

So, imagine the scene. You’re in a mid-elevation canyon in Southeast Arizona, excited about your prospects of finding one or two of the famous specialty birds that brought you to this fantastic birding Mecca. You see a small, long-tailed, gray-and-white bird in the distance. It looks like a gnatcatcher. It moves, and you now see that it definitely has a black cap. Hello! This is going to be interesting.

At this point you can already narrow it down to one of only two things – a male Black-capped Gnatcatcher, or a male Black-tailed Gnatcatcher, which in reality is much more likely as it’s by far the commoner bird. Blue-gray Gnatcatcher never shows a black cap in any plumage, although beware breeding males, which do show a small, black forehead and line above the eye. You’re far enough inland that you don’t have to worry about California Gnatcatcher.

Black-capped Gnatcatcher

The bird turns its head, and gives you a different view. You can now see that it has a long bill for a gnatcatcher, typical of Black-capped, and doesn’t appear to have any kind of white eye ring to speak of, which should be visible in a male Black-tailed. If you’re really confident, that’s enough – congratulations, it’s a male Black-capped Gnatcatcher. But you should try to see more, to be absolutely certain.

Black-capped Gnatcatcher

It moves again, and now you get a better view of the spread uppertail. Of course, you want to see the undertail, but so far it’s refusing to show you.

If you’re dealing with a female or non-breeding male without a black cap, the uppertail pattern won’t really help you rule out Blue-gray Gnatcatcher without an incredibly close view, most likely in the hand, as they’re pretty similar. In both Black-capped and Blue-gray, the two outermost tail feathers are largely white (with a bit of black at the base in western Blue-grays) with an additional white tip and outer web on the next tail feather.

One thing that will help, even with views of just the uppertail, is that Black-capped also has a more graduated tail, meaning that the outermost tail feather is noticeably shorter than in the other two gnatcatchers in question, with the next tail feather being slightly shorter, giving a more rounded look. It’s subtle, but can be seen with reasonable views.

Black-tailed Gnatcatcher, on the other hand, has less white on the tail sides as seen from above – just the tip and outer web of the outermost two tail feathers. Views of the spread uppertail, such as the ones below, combined with the black cap, long bill and lack of obvious eye ring, are another clincher for the ID being Black-capped – the shorter outer tail feather, slightly shorter second feather, and white tip and outer web of the third tail feather all rule out Black-tailed.

Black-capped Gnatcatcher

Black-capped Gnatcatcher

But you still want to see more. The bird comes a little closer…

Black-capped Gnatcatcher

Black-capped Gnatcatcher

Black-capped Gnatcatcher

And finally it shows you the undertail – largely white, as you’d hoped, and at this point, expected.

Black-capped Gnatcatcher

There’s one more thing you should consider, that can lead you down the wrong path when identifying gnatcatchers – the dreaded issue of molt. In early spring and late summer, male gnatcatchers are molting their head feathers, so can look anywhere between the breeding and non-breeding males you see in your field guides. This can render the shape of the black cap, and to some extent the presence or absence of an eye ring, somewhat unreliable as clinching features on their own.

Furthermore, in late summer, gnatcatchers molt their tail feathers, sometimes all at once! A bird that has shed just its outer tail feathers, and therefore appears to have limited white in the outer tail, might lead you to prematurely dismiss a genuine Black-capped Gnatcatcher as a Black-tailed, before you see the undertail.

But it all fits today, and there it is: a fine male Black-capped Gnatcatcher. Now… who’s that female he’s hanging around with? This time, you really DO need better views. Good luck with that!


1 comment to How to… Identify a Distant Male Black-capped Gnatcatcher

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