Brown-capped Rosy-Finch Life History

Habitat

For most of the year, Brown-capped Rosy-Finches live high in the Rocky Mountains above treeline in alpine meadows that are often partly covered by snow. This tundra-like habitat provides an abundance of seeds and insects that forms the birds’ diet. For nesting, these rosy-finches require protection from strong winds, storms (common in high elevations), and falling rocks. They make their nests in cliffs, caves—any structure that protects the nest will do, even huts or old rockslides. They nest as high as 14,200 feet, usually near feeding areas on meadows, glaciers, snowfields, moraines, cirques, and slopes called “fell fields,” where gaps in scree hold an abundance of seeds. Because they regularly feed on windblown seeds and insects on top of glaciers and snowfields, they remain above treeline for most of the year. In most winters, large numbers descend into shrubby and forested habitats of lower elevations, where they frequent feeding stations and show little fear of humans, entering backyards, barnyards, buildings, mines, tunnels, and even old Cliff Swallow nests, to seek food and shelter.Back to top

Food

Brown-capped Rosy-Finches forage on the ground in open meadows as well as on glaciers and snowfields, shuffling and hopping to pick insects or seeds from surfaces or occasionally chasing insects in flight. Much of their foraging occurs along the edge of melting snowfields. They consume a variety of bugs, flies, beetles, moths, and other insects, as well as spiders, especially in summer, and their winter diet consists mostly of seeds, including those of grama grass, pigweed, lovegrass, Scribner wheatgrass, tufted hairgrass, bluegrass, white marsh-marigold, chickweed, rubberweed, knotweed, mustard, thistle, and many alpine flowering plants. For much of the year, they take seeds from the ground, but toward the end of summer, they begin eating the new seed crop, pulling seeds directly from the plants. Back to top

Nesting

Nest Placement

The female probably selects the site site, from among several sites the male shows her. Nests are set in recesses in cliffs, caves, rocky fields, and sometimes in human-made structures (buildings, mines), so long as there is protection from weather and falling rocks.

Nest Description

The female builds the nest, a tight cup of grass, plant stems, and rootlets that usually is set into a coarse exterior of mud, moss, and heavier plant stems. Some nests include ptarmigan feathers, elk or rabbit fur, or bits of cloth. Nests average about 5.2 inches across and 2.9 inches tall, with interior cup 2.5 inches across and 1.6 inches deep.

Nesting Facts

Behavior

Males sing, both from the ground and in aerial song displays, to attract females, and once a female is present, males court by fluffing the body feathers, raising the head and tail, spreading and quivering the wings, all while calling and perhaps presenting the female with sprigs of nesting material. Receptive females perform a similar display and beg food from the males with open bill. Although males sing at this time, they do not appear to use song to mark or maintain nesting territories. Rather, they follow females fairly closely, enforcing what ornithologists call a “floating territory” around her, should there be a rival male that approaches her too closely. Once she lays eggs, the male’s mate-guarding behavior is less pronounced. Both sexes share incubation and chick-rearing duties. After the young fledge, family groups may forage together and eventually join others to form flocks.

Conservation

Brown-capped Rosy-Finch populations may be declining. Partners in Flight estimates a global breeding population of 85,000 and rates the species 16 out of 20 on the Continental Concern Score. They include the rosy-finch on the Red Watch List for species of highest concern. Climate change imperils alpine habitats, which are losing glaciers and snowfields, key habitat for rosy-finch foraging. Moreover, warmer global temperatures permit shrubby habitats below alpine meadows to advance upslope, further reducing habitat available to species such as Brown-capped Rosy-Finch.

Credits

Johnson, Richard E., Paul Hendricks, Donald L. Pattie and Katherine B. Hunter. 2000. Brown-capped Rosy-Finch (Leucosticte australis), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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