FOX SPARROW Passerella iliaca
These big medium-brown sparrows with variable grayish faces and heavily streaked or blotchy undersides can be found in summer at higher elevations across much of the state except the Coast Range. Darker brown birds from more northerly breeding populations are common to locally abundant in western Oregon in winter, often coming to feeders, where they scratch like towhees for seed on the ground.
General distribution: Breeds from the maritime provinces across nc. Canada and c. Alaska, also south at high elevations in the Rockies and the Cascade-Sierra ranges and locally in the Great Basin. Winters in the e. U.S., the desert southwest and along the Pacific coast to s. British Columbia. Eighteen subspecies, some well-marked and with distinctive movements, were recognized by the AOU (1957). A different assemblage of 17, including recently recognized chilcatensis (Browning 1990) is commonly used by banders (Pyle 1997). Subspecies are often treated as three general morphological groups (Swarth 1920). Zink (1986) considered there to be four groups, an arrangement that is generally followed by Zink (1994), Rising (1996) and Pyle (1997). Rising treats these groups as separate species but the AOU Check-list (1998) does not; we follow the AOU. Subspecies distribution below is from Gabrielson and Jewett (1940) and AOU (1957) except as noted.
Oregon distribution: We recognize fulva as a separate subspecies (contra Pyle 1997) pending additional research. Statements of range below are based mainly on measurements of specimens or in-hand live birds. Even relatively recent studies such as Zink's (1986) involved few specimens per site (Browning 1995) and more research on subspecies is needed.
P. i. schistacea breeds in the Blue Mtns. (not currently in the Ochocos) and locally in the Owyhee Uplands. P. i. fulva breeds in the e. Cascades from c. Klamath Co. se. to the Warner Mtns. and perhaps Steens Mtn., also n. locally to w. Deschutes Co., less common n. to the "breaks of the Columbia River south of [The Dalles]" (Gabrielson and Jewett 1940; we treat "Bend" in their account of fulva as erroneous, actually referable to The Dalles). P. i. megarhyncha breeds in the Siskiyou range west to e. Curry Co. (D. Vroman p.c., Cushing 1938, Dillingham 1994), east to the Cascades of sw. Klamath Co. (Zink 1986, M. R. Browning p.c., AC) and north probably to e. Lane and at least occasionally to e. Linn Co. (Swarth 1920, Zink 1986, Banks 1970). Measurements of specimens from s. Lake, n. Klamath and w. Deschutes Cos. suggest that these birds are fulva. USNM specimens from Annie Cr., Ft. Klamath and head of Whiskey Cr. are fulva (M. R. Browning, p.c.). Specimens from sw. Klamath Co. are within the measurement range for megarhyncha (Zink 1986, AC). This suggests that the Klamath Basin lowlands may be a natural break between fulva and megarhyncha - an intergrade from Keno, Klamath Co. is in the USNM (M. R. Browning p.c.).
Recent banding work on Steens Mtn. found birds with bill measurements too small for fulva, though it was previously thought to be the breeding subspecies there. It is unclear whether fulva or schistacea breeds on Steens Mtn., Wagontire Mtn. or in the Pueblo, Trout Creek or Oregon Canyon ranges. Habitat in these areas is isolated and populations are limited. Most sources treat all Blue Mtn. birds as schistacea (AOU 1957, Behle and Selander 1951, Booth 1952, Smith et al. 1997), but Aldrich (1943) considers olivacea a breeding form in the ne. Blue Mtns.
Birds of uncertain subspecies breed in the w. Cascades from Lane Co. north to Clackamas Co. and across the summit in adjacent w. Jefferson and w. Wasco Cos. Most field measurements of live birds in this region are consistent with the small end of the megarhyncha/fulva group as defined by Pyle (1997). Birds on both sides of the northern Cascade ridgeline are similar in measurements and are indistinguishable by sight and song (S. Dowlan p.c.). It is possible that megarhyncha grades northward into fulva in the n. Cascades as suggested by Pyle, or that fulva as recognized by previous authorities is expanding its range. Data is not yet sufficient for a definitive statement of ranges (S. Dowlan in prep.).
The breeding complex departs the state to winter in California and the southwest and is replaced in Oregon by birds that breed in Alaska and western Canada. These populations overlap somewhat in Oregon but there is some geographic sorting. Winters abundantly on the coast and in the coast ranges (probably P. i. fuliginosa and chilcatensis [specimen from Tillamook, fide M. R. Browning], see Webster, 1983) but Swarth (1920) considers fuliginosa to be largely sedentary and notes that wintering birds in California are placed "reluctantly" into that subspecies. Also wintering in w. Oregon in smaller numbers are P. i. townsendi and P. i. sinuosa (Gabrielson and Jewett 1940, Swarth 1920, Zink 1986). Common in the western interior valleys, where little information about subspecies is available.
A few winter locally into the w. Cascades below the elevation of consistent snowpack. A few winter east of the Cascades as far north as Umatilla Co. (C. Corder p.c.), but their subspecies and origin is unknown.
Other subspecies that breed north of Oregon pass through as migrants but winter in small numbers or not at all. Among these are altivagans, unalaschensis, annectens, insularis and olivacea (Gabrielson and Jewett 1940, Aldrich 1943, M. R. Browning p.c.). Specimens of annectens from Beaverton 27 Feb and Netarts 12 Jan (Univ. Utah, fide M. R. Browning) suggest that it winters at least occasionally, as is true of unalaschensis, which has been collected at Nehalem on 14 Jan and 7 Dec. (Amer. Mus. Nat Hist, fide M. R. Browning) and at Carlton on 15 Jan (U. S. National Mus., fide M. R. Browning). Winter specimens of insularis are known from Portland, Netarts and Grants Pass (M. R. Browning, p.c.). Bright, streaky "Red" Fox Sparrows of either the iliaca or zaboria subspecies are occasionally seen in Oregon, mainly in winter west of the Cascades (AC; Oreg. Birds field notes). It is not known which subspecies these represent.
A thorough review of existing specimens from all seasons and parts of the state and additional collecting is recommended to clarify the identity and status of Oregon populations.
Habitat and diet: This is a species of dense low shrub growth. The ground cover used by breeding birds varies remarkably, probably as widely as for any Oregon passerine. Snowbrush (slickleaf ceanothus), mountain mahogany, chokecherry, greenleaf manzanita, willow, red-osier dogwood, sagebrush and even regenerating 15-25 yr old Douglas-fir and noble fir have all been reported as breeding habitat in Oregon (Gabrielson and Jewett 1940, Fix 1991, MH, Littlefield 1990, Contreras and Kindschy 1996, Farner 1952, S. Dowlan p.c.). L. Fish notes that in the Owyhee Uplands they are present "most often in young aspen with manzanita, snowberry and wild rose." Farner (1952) noted that the species uses "willows, alders and small firs" but to a lesser extent than manzanita and ceanothus. Evanich (1992) notes that the species breeds in "boggy coniferous forest edges" in northeastern Oregon. Nests are placed on the ground or in low shrubs (Rising 1996).
Migrant and winter birds use equally dense structures, with coastal birds most abundant in salal thickets and those in the western interior valleys in Himalayan blackberry tangles and dense residential shrubbery.
Seasonal activity and behavior: Birds breeding in the Cascades arrive in mid-Apr (Fix 1991, Dowlan in prep.). At Malheur NWR the average arrival of spring migrants is 13 Apr, with the earliest recond 16 Mar and peak of passage the last two weeks of May. Studies at Hart Mtn. show that breeding birds are present by the third week of May and that laying occurs as late as 3 Jul (Mewaldt, unpublished data). Wintering birds in w. Oregon begin moving in late Mar (AC) and most are gone by late Apr (Contreras 1998, Gillson 1999).
Birds breeding in the s. Cascades depart in Sep (Fix 1991). Fall movement at Malheur is extended, with birds arriving as early as August (earliest 5 Aug) and peak of passage from 15 Sep to 5 Oct. Stragglers occur into Nov and the species is a rare winterer (Littlefield 1990). Migrants from the north appear in late Sep and Oct in w. Oregon (Fix 1991, Gullion 1951, Gillson 1999, M. R. Browning p.c.). S. Dowlan (p.c.) notes a peak the second week of Sep in the nw. Cascades. Farner (1952) notes that P. i. sinuosa migrates through Crater Lake in Sep, though it does not winter there. A gray-headed bird of one of the breeding subspecies was noted at Toketee Ranger Station, Douglas Co. on 19 Nov 1988, a very late date (Fix 1991).
Detection: Detecting birds in the breeding season is easy, seeing them is not. The song of this species is loud, melodious and easy to distinguish from other species, except when Fox Sparrows and Green-tailed Towhees are singing, mixed, in the underbrush of open pine forests, when the blur of sound makes picking out a singer difficult. Breeding birds are fairly secretive, seen as they dash from clump to clump. Winter birds are far more visible, being ubiquitous at feeders and in brushy areas throughout w. Oregon. Breeding races in Oregon are very reluctant to call and have quieter call notes than winter birds, whose heavy "check" can be heard in any west-side blackberry tangle.
Status and Conservation: BBS data show a 3 percent decrease 1966-1996 (P=.06). CBC data (counting a completely different population) show a 5.8 percent increase 1959-1988 (P=<.01). Breeding birds are dependent on the availability of dense shrub cover, but a wide variety of plant species are used.
The species was not known from the west side of the Cascade summit north of Jackson Co. early this century (Gabrielson and Jewett 1940). Clear-cut logging has probably benefitted the forms that breed in w. Oregon by opening new brushfields to colonization (MH, Webster 1983); logging typically retains some low shrub growth and regeneration may be faster than after fires. The species may be more widespread west of the Cascade summit since logging reached higher elevations in the 1960s and 70s but this apparent increase may be an artifact of easier observer access to habitat because of road-building (MH). The species was first found at Lava L. in Linn Co. in 1968 (W. Thackaberry p.c.) and is now locally common from e. Linn Co. n. to at least c. Clackamas Co. (S. Dowlan p.c.)
Ponderosa pine forests with dense ground cover often support breeding Fox Sparrows and breeding may continue after logging, thus it is probably relatively insensitive to loss of timber east of the Cascades, though little information is available.
Birds breeding in the Basin and Range and Owyhee Uplands are more limited in available habitat and are therefore more sensitive to disturbance; activities such as grazing in sensitive riparian areas and human clearing of streamside vegetation would essentially eliminate the species from large areas.
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