Other Information
SE
Arizona Rare
Bird Alert
(520) 798-1005
Report
Rare Birds
(520) 798-1005
Email
a report
Nature Shop
(520) 629-0510
Agua Caliente Shop
(520) 760-7881
Mason Audubon
Center
(520) 744-0004
Membership
(520) 629-0757
AZ IBA Program
(520) 628-1730
Education Program
(520) 622-2230
Habitat Restoration
(520) 206-9900
Development
(520) 622-5622
Executive Director
(520) 622-5622
|
Birding home | Access updates | RBA | Dastardly Duos | AZ/NM listserv | Tucson area |
Tucson Audubon Society
Dastardly Duos
Blue-gray, Black-tailed and Black-capped
Gnatcatchers
by Larry Liese
Illustrations by George C. West
(Article first appeared in the February 2003 Vermilion Flycatcher
newsletter. To receive the newsletter in the mail, become a member of
the Friends of Tucson Audubon.)
Have you read how most experts say that
rare birds get found by people who really study their area’s common birds?
That way, they are prepared for that odd time when a bird doesn’t quite
look or sound right. This month’s Duo actually is of three species: the Black-capped
Gnatcatcher (Polioptila nigriceps), the Black-tailed
Gnatcatcher (Polioptila melanura), and the Blue-gray
Gnatcatcher (Polioptila caerulea). In their different plumages,
telling the three apart can be tricky, and familiarity with the common two
will certainly come in handy.
In southeast Arizona we get the
Black-capped most years, usually between March and August, though as I’m
writing this, a pair has been parked at Patagonia Lake through the winter
holidays. They are very local in habitat choice here, having been found
mostly in Chino Canyon, around Patagonia Lake, and in Sycamore Canyon in
recent years. Black-tailed inhabit desert scrub year-round, and Blue-grays
breed higher up in oak and pine-oak woodland, with some moving down into
desert washes in winter.
The main year-round differences between the three are in the undertails, bill, and voice. The male Black-capped sports his black cap only from about February through August, and the Black-tailed from February through July. If you see a male in breeding plumage, look for an eye ring. The Black-tailed will have one while the Black-capped has only a thin crescent below the eye. Also, the Black-capped has a more solidly black cap that extends below the eye.
Voice is key as that is how one usually first knows a gnatcatcher is in the area. Calls are quite different but can be hard to describe. I think of the Blue-gray as having a Gnatcatcher-like call that isn’t raspy like the Black-tailed. I’ve heard the Black-capped give the mewing call it’s famous for, but I’m unfamiliar with the other sounds that field guides describe. A birding buddy of mine, Melody Kehl, notes that the Black-capped vocalization is very drawn out, like a Blue-gray with a southern drawl. I’ll have to remember that the next time I’m at Patagonia Lake! If you’re trying to find a staked-out Black-capped, my best advice is to ask yourself: "Is it a funny sounding gnatcatcher?" Then, look at the bill.
Some years ago, Dick Palmer, another birding friend of mine and fellow Mexico birding aficionado, said "look at the bill", when we were discussing gnatcatchers. Since then, I’ve found this a lot easier than looking for head pattern differences. The Black-capped has a long, very pointed all-dark bill that is distinctive. Blue-grays have a shorter bill that can be flesh-colored below at the base. Blue-grays have a bold white eye ring, while the others have a more muted one when present. Some field guides refer to wing and back colors as being different, but this would take some practice to get familiar with.
Now for the undertails: Black-tailed Gnatcatchers have a mostly black undertail with white edges and white blotches near the tail tip, while the others have all-white undertails with a central dark streak. These are easy to see if given a reasonable view. Incredibly harder to see is the more graduated length of the tail-feathers on the Black-capped compared with the Blue-gray. I have tried viewing this on both species without much luck. It would probably be viewable on a dead bird, but the little guys just don’t stay still long enough to get a view of this field mark!
So, get on down to Patagonia Lake and hope the pair is still around, or wait for summer and monitor the hotline for reports from Chino Canyon adjacent to Madera Canyon for a chance on a Black-capped. In the meantime, take some close looks at our ‘regular’ gnatcatchers. Good luck!
Bird questions? Check Birding | General questions? Contact: Tucson Audubon Society | Webmaster: Email
This page was updated on 02/21/06