Common Name: Fox Sparrow
Scientific Name: Passerella iliaca
Scientific Order: Passeriformes
Scientific Family: Emberizidae
Appearance: The Fox Sparrow is a large sparrow - stout and round-headed (length 7.5" [15.0–18.5 cm cm], weight: 1.1 oz [25–49 g]). Fox Sparrows exhibit such wide variation in size, appearance, and sounds that four main subspecies are sometimes considered separate species, although each intergrades at their range margins. In general, most birds have stout, bi-colored conical bills, large feet and claws, and long wings. Most birds have rufous rumps, tails, and wings. Breast and flanks streaked, merging into spots which may form a central spot on the central breast. Both sexes appear alike.
Habitat/Where to find: Common to uncommon in dense undergrowth, alder thickets, woodland edges, chaparral, and grown-up fields in areas dominated by coniferous or mixed woodland forests. The Red subspecies breeds from AK east to Nova Scotia and winters along the Pacific coast south of BC and throughout the U.S. east of NM. Sooty birds breed in the Aleutian Islands to southern BC and winter from BC south to San Diego. Slate-colored breeds from interior BC south to NV and CO, and winters in central CA , south to Baja and east to NM. Large-billed birds breed from OR south to Baja, and winter in central CA south to Baja.
Sounds: Fox Sparrows produce substantial variation in sounds, depending on the subspecies. In general, their sounds are loud, clear whistles with short trills. Northern "Red" birds exhibit richer, warbling melodies in their sounds, while other subspecies produce harsher sounds. "Thick-billed" and "slate-colored" males sing multiple songs in sequence, and then repeat, while "red" and "sooty" males which sing just one song. Call notes resemble a loud "smack", and the flight call is a high-pitched "seeep".
Behavior: Fox Sparrows defend exclusive territories during the breeding season, and therefore appear solitary or in pairs. Small flocks associate during migration and on the wintering grounds. Fox Sparrows usually fly only short distances on rapidly beating wings alternating with short periods of rest. They fly close to the ground and nervously pump their tails after being disturbed. Parents sometimes give the broken wing display in defense of young fledglings.
Reproduction: Fox Sparrows are monogamous, solitary nesters. Females construct nests in shrubs or on the ground shortly after males establish territories soon after arrival of spring migrants. Primary nest materials include lichen, roots, bark, and leaves, with cup lining of grass and moss. Females incubate 2-5 pale green eggs for 12-14 days, and nestlings are fed by both parents. Nestlings fledge after 9-11 days in the nest. Fox Sparrows normally produce two broods each year.
Food Habits: Similar to towhees, Fox Sparrows forage by double-scratching on the ground, and also by excavating small holes with their claws. During the breeding season, Fox Sparrows mainly consume arthropods including insects and spiders. At other times of the year, the diet expands to include small mollusks, seeds, fruits, and buds of plants.
Vital Statistics: The longevity record for Fox Sparrows is held by one bird known to have lived for at least 9 years and 9 months. Annual survival estimates is 10% for juveniles and 27-35% for adults.
Migration/Dispersal: Small groups of Fox Sparrows travel together during winter migration, mostly at night. No information exists regarding dispersal of juvenile Fox Sparrows. Little information exists regarding dispersal of adult Fox Sparrows. At least 20% of adults return to the previous year's breeding location, but it is unknown what proportion of the missing birds survive and breed elsewhere.