Harris's Sparrow

This species is the largest of the sparrows in the family Passerellidae, though other superficially dissimilar species in the family may slightly exceed them in size. They range in total length from 17 to 20 cm (6.7 to 7.9 in), with a 27 cm (11 in) wingspan and weigh from 26 to 49 g (0.92 to 1.73 oz). Among standard measurements, the wing chord is 7.7 to 9.2 cm (3.0 to 3.6 in), the tail is 7.6 to 8.8 cm (3.0 to 3.5 in), the bill is 1.1 to 1.4 cm (0.43 to 0.55 in) and the tarsus is 2.2 to 2.5 cm (0.87 to 0.98 in). This is a very distinctive looking species. Breeding plumage birds have conspicuous pink bills and black on the crown, face, throat and upper breast, contrasting with grey on the sides of the head and neck. The back is brown, overlaid with heavy black streaking. There are two white wing bars. Breeding birds have white lower underparts with some black mottling on flanks. Non-breeding adults are more buffy than grey and brown, with reduced or absent black markings and often have whitish scalloping on the head and throat. Immatures have less black than all adult plumages, normally marked with a white chin and throat, a black malar stripe and a broad smudgy black breast-band. Juveniles have a brownish crown streaked with black and fine dark streaks and some broader black markings on the underside. Birds moult from July to September. …

Harris's sparrow breeds in stunted coniferous forests and adjacent scrubs, especially areas of the grand boreal forests where stands of spruce abut mossy bogs. They often nest near the northern limit of tree growth in the forest-tundra ecotone. Typical plant life in the breeding grounds consist of white and black spruce (Picea glauca and P. mariana) and American larch (Larix laricina), dwarf birch-willow, and wet sedge meadow and shrubby tundra with dwarf ericad/lichen plant life. The species migrates mainly through tallgrass prairies to winter in open woodlands, woodland edges and clearings, hedgerows, dense riparian thickets and around brush piles. Harris's sparrow regularly occurs at feeders in suburban and rural gardens during the wintertime. They typically avoid dry shortgrass prairies and dense woods during winter. Migrating sparrows may be attracted to marsh elder (Iva annua) and giant ragweed (Ambrosia trifida).

Harris's sparrow generally feeds on the ground, scratching vigorously in the leaves and soil for food. Observed foraging during nesting was 85% ground-gleaning. During the breeding season individuals typically forage alone or with a mate. Primary in the diet (66% of stomach contents of breeding birds) are seeds, largely of Carex sedges, grasses and Scirpus bulrush. Also important in the breeding season diet are fruits, largely black crowberry (Empetrum nigrum), mountain bearberry (Arctostaphylos alpina) and various Vaccinium species. Pine needles, flower buds and blossoms are eaten supplementally. Larval invertebrates are important from June to September in the diet, as available prey becomes more common at this point. The principal preferred animal prey includes beetles, flies, bees, ants, moths, butterflies, spiders, cicadas, aphids and leafhoppers. The diet of wintering Harris's sparrow is less well-known and has not been quantitatively studied.