Proposed split: Gambel's and Bailey's Chickadees

Proposed Gambel's Chickadee, spp. grinnelli, King Mountain, Harney Co., Oregon, 26 May 2009 by Greg Gillson.

 

There is a recent proposal before the A.O.U. (American Ornithologists' Union, Committee on Classification and Nomenclature, North & Middle America) to split Mountain Chickadee, Poecile gambeli into two species. The new species would tentatively be called Gambel's Chickadee Poecile gambeli and Bailey's Chickadee Poecile baileyae.

Both of these forms of Mountain Chickadees are common in the Pacific Northwest.

As is the case for several recent splits of North American birds (Winter and Pacific Wren is a recent example), published research showing differences in songs and calls, together with supporting DNA evidence, were the primary deciding factors for recommending separation. They don't really look that much different.

Not all recommendations to the committee are passed. But if accepted, the A.O.U. could update its checklist in July 2011, making this split official.

Mountain Chickadees are found from the Rocky Mountains westward in drier pine forests to timberline.

The proposed Gambel’s Chickadee is found in the Great Basin and Rocky Mountains. In the Pacific NW it is found in mountain forests and juniper woodlands in interior British Columbia, northern Idaho, SE Washington, and NE Oregon (to the Ochoco Mountains in north central Oregon).

The proposed Bailey’s Chickadee is found in coastal California, Sierra Nevada, and the Cascades of Oregon and Washington. In the Pacific NW it is found in the Klamath Mountains of SW Oregon and northward primarily on the east slope of the Cascades to Mt. Rainier but, apparently, not in British Columbia (Birds of Canada. 1979. Godfrey).

There may be some areas in the Pacific NW where the two forms come together.

In the field, the primary separation of these forms is range (they are non-migratory) and breeding song. In-hand measurements can be used to identify captured birds or specimens. On average Gambel's is tinged buffier below with a wider white eyestripe and perhaps more white on the lores. But a comparison of the two photos here shows how difficult this identification would be based only on plumage. Both the Sibley and the National Geographic guides illustrate the two forms of Mountain Chickadees.

Gambel's Chickadee reportedly has a wider range of pitch between song notes than Bailey's Chickadee. If this split goes forward birders will need to really listen to the songs. Listen to Mountain Chickadee songs.

 

Proposed Bailey's Chickadee, spp. abbreviatus, Sunriver, Deschutes Co., Oregon, 3 February 2008 by Greg Gillson.

 

In the mountains... Mountain Chickadee

Mountain Chickadee in a lodgepole pine, Lost Lake, Linn Co., Oregon on 23 May 2009 by Greg Gillson.

 

Several groups of Pacific NW birds show altitudinal habitat preferences. This is most clearly seen on the Cascade Mountains. The chickadees show this, with Black-capped Chickadees most common in lowlands and oak woods west of the Cascades. Higher up the Cascade slope, in the damp Douglas-fir and western hemlock habitat zone is the domain of the Chestnut-backed Chickadee. In the highest forests of lodgepole and over the Cascade crest to the drier east side ponderosa pine forests are found the Mountain Chickadees (sometimes in lower juniper).

Instantly recognized by the white eyebrow stripe, Mountain Chickadees are pale gray, white, and black. They lack the chestnut backs (and sides of all but the San Francisco area populations) of Chestnut-backed Chickadees. They lack the buffy sides of the Black-capped Chickadees west of the Cascades. [In the Rocky Mountains are some rather plain sided Black-capped Chickadees and some rather buffy-sided Mountain Chickadess.]

The common call is a husky chick-dzee-dzee-dzee. The song is similar to Black-capped Chickadee, a whistled descending fee-bee-bay.

These birds are very common in mountain forests. In fact, Farner in 1952 wrote that these birds are the most common resident species at Crater Lake National Park.

Mountain Chickadees nest in old woodpecker holes, nest boxes, or other opportunistic crannies.

Like all chickadees, these birds are attracted to backyard bird feeders in the towns in the pines on the eastern edge of the Cascades and other higher mountains. They also occur in the Klamath Mountains nearer the coast in NW California.

Deposit Comments

Mountain Chickadee nesting in "comments" box, Idlewild Campground, Harney Co., Oregon on 26 May 2009 by Greg Gillson.

 

Above is a photo from this spring. I found this Mountain Chickadee with a nest in the suggeston box at a trailhead. I thought it very humorous. Earlier in the day I had found another nest of this species in a more typical location--an old woodpecker hole in a ponderosa pine tree.

I am preparing more information on Mountain Chickadees for a post on October 19....