Breeding Fox Sparrows in Oregon
The historical range of breeding Fox Sparrows in Oregon is confused. According to published literature which contains subspecies (AOU 1957): 1) The Slate-colored form, schistacea, breeds in the Blue Mts. and adjacent brushy canyons in extreme NE Oregon, 2) the Thick-billed form, megarhyncha, breeds in the Siskiyou Mts. of extreme SW Oregon, 3) another Thick-billed form, fulva, breeds in the Klamath Basin and the east slope of Oregon's southern Cascades, and in the desert range of the Steens Mts. Pyle (1997) does not recognize fulva, thus all Cascades, Warner Mts., and Rogue Valley Thick-billed types must be megarhyncha.Steve Dowlan has done considerable banding of Fox Sparrows in various areas of Oregon in recent years. His preliminary data is incorporated into the Fox Sparrow species account by Contreras (2002). Rather than being the last word on the subject, it brings readers up-to-date on current thinking and documented past records.
The Oregon Breeding Bird Atlas (1995-1999) mapped Fox Sparrows in the following areas. The subspecies labels are our "best guess" as of the year 2000.
Slate-colored (schistacea) Fox Sparrows in the northern Oregon Cascades?
What about the references to schistacea from Warm Springs, near the northern Oregon Cascades (Walker 1917)? There is no indication that specimens were actually collected. Walker wrote: "Paserella iliaca schistacea: Noted as more or less common at Warm Springs and in the pine timber at Foley Creek. Early in May they were plentiful in the timber along Mill Creek on the Warm Springs Indian Reservation, frequently in thick growth of little pine seedlings, rather than the brushy creek bottoms, their usual habitat."
Steve Dowlan (pers. comm.) wrote: "I think the last sentence is key here. Walker was surprised to find this subspecies away from the brushy creek bottoms... because, I believe, THEY WEREN'T SHISTACEA... they were fulva." This conjecture makes sense given the present numbers of fulva at this location, and in this habitat. Dowlan did some banding in this area in 1998. All birds matched fulva and NOT schistacea.
Slate-colored (schistacea) Fox Sparrows in the Ochocos?
Garrett et al. (2000) state that "The ranges in Crook County harbor breeding schistacea (Gabrielson and Jewett 1940) and perhaps fulva as well." Gabrielson and Jewett, however, never state that there are Fox Sparrows in Crook Co., though their rough map might indicate so. Gabrielson and Jewett give the range in their text as the Blue Mountains south through Malheur County, not the Ochoco Mts. As the BBA map shows, there were no breeding Fox Sparrows found in the Ochocos at all during the 5 years (1995-99) of the Oregon Breeding Bird Atlas Project (though there were recent historical observations of unknown subspecies; see map). At most, it appears that Fox Sparrows of unknown affinities may occassionally breed in the Ochocos. This is an area of needed research.
Slate-colored (schistacea) Fox Sparrows in Jefferson County?
There may be old specimens of schistacea from Jefferson Co. But, if they ever bred, this race appears not to be present any longer. Certainly, the common breeding form in the Cascade foothills are fulva. However, one should not dismiss the race olivacea, from the Slate-colored group, which nests in the Washington Cascades and replaces fulva there. The olivacea form was formerly considered schistacea and wasn't described until 1943 (Jewett et al. 1953, AOU 1957).
Are the Cascades birds (fulva) different from the Siskiyou birds (megarhyncha)?
What about megarhyncha? This form of the Siskiyou Mountains supposedly is larger-billed and longer tailed than fulva. Pyle (1997) does not recognize fulva as distinct from megarhyncha. A recording by Eleanor Pugh at the corner of Jackson/Josephine/Douglas Cos. (megarhyncha range) sounds just like the birds in Wasco Co. (fulva range); Fox Sparrows in Wasco Co. aggressively defended territory when this tape was played. Steve Dowlan has not made measurements of birds in the Siskiyous, but Fox Sparrows are continuous from this area to the Cascades. Songs, plumages, and habitats appear identical to the field birder.
Zink (1986) compared the DNA of several populations with typical megarhyncha. The Warner Mountain [WARN] sample of northern California (type locality of the fulva race) matched to 85% of megarhyncha. The Odell Lake [ODEL] sample from the southern Oregon Cascades matched 100%. Measurements and observations of songs, habitats, and plumage of birds in the Warner Mts. of southern Oregon by Dowlan in 1999 (pers. comm.) matched those of the Cascades. It seems, then, that populations in the Oregon Cascades are not significantly different from megarhyncha or fulva.
Where do the Thick-billed Fox Sparrows end and Slate-colored Fox Sparrows begin in southeastern Oregon?
Swarth (1920) wrote: "Breeding birds from various points in central Oregon exhibit considerable diversity in size and shape of bill and in relative grayness and browness of color, though all, I believe, are best referred to as fulva."
Steve Dowlan and I have to take exception with placing Fox Sparrows on the Steens Mountains [STEN] cleanly in fulva. Bill depth (Zink and Kessen 1999) at 7.5 mm is very close to schistacea samples in northern Nevada ([RUBY] and [MART]). The DNA is only a 50% match with megarhyncha. (RUBY and MART are 0% match with fulva, however.) The habitat usage of Fox Sparrows on the Steens is riparean, NOT manzanita scrub. And, most persuasive, the song is noticably different from fulva birds in the Cascades and Warner Mountains. I would suggest they are an intergrade population between fulva and schistacea.
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