White-tailed Ptarmigan Life History

Habitat

Year-round, White-tailed Ptarmigan live in alpine heath or tundra habitats, mostly above treeline, to elevations exceeding 14,000 feet. Their range extends from Alaska to New Mexico, in open, mostly treeless areas with scattered lichen-covered rocks. Most vegetation is a foot high or less. Trees, if present at all, tend to be stunted and sculpted by high winds (known as "krummholz," from the German for "crooked wood"). At the lower part of the ptarmigan’s elevational range, spruce, subalpine fir, and white fir may grow in small clusters among alpine meadows. Willows such as net-leaved willow often grow low to the ground. Tundra plants grow in profusion, including alpine avens, Parry’s clover, alpine sagewort, creeping sibbaldia, snow buttercup, and many grass and sedge species. White-tailed Ptarmigan often forage in "fellfields," areas where freezing and thawing have opened crannies in steep slopes, allowing small plants enough moisture and shelter to grow. Ptarmigan also frequent areas near streams and at the edges of melting snowfields. They often stay close to taller vegetation or rocks, where they can take shelter or hide from predators. As storms commence in autumn, these grouse move downslope into more sheltered areas, especially into basins or bottoms where willow, alder, and birch grow around meadows with sedges and grasses. If weather is especially severe in winter, some move below treeline into forests of hemlock or other coniferous species.

Food

White-tailed Ptarmigan eat plant buds, stems, seeds, leaves, fruits, and flowers. In the warmer months, they also eat insects. They forage mostly on the ground, using their small, sharp bill to clip the vegetation. They readily perch in shrubs such as willow and alder to gain access to the new foliage or flowers as well. Although White-tailed Ptarmigan do feed in areas of heavy snowpack where vegetation pokes above the snow, for much of the year they seek out areas where winds have swept out snow or where snow has melted, exposing seeds that had been covered. Plant foods include alpine avens, mountain avens, alpine bistort, alpine clover, Parry’s clover, Arctic willow, plainleaf willow, barren-ground willow, Jones’s sedge, white mountain heather, pink mountain heather, Oregon stonecrop, alpine bearberry, crowberry, and various species of blueberry, sedge, and grass. Like many other birds, they consume grit to help them grind their food in the gizzard.

Nesting

Nest Placement

The female probably selects the nest site, always on the ground, usually with both good visibility (to spot predators) and several escape routes.

Nest Description

The female makes a shallow depression with her feet, lining it with dry grass, leaves, and feathers. The interior of the nest averages about 5.9 inches across and about 1.4 inches deep.

Nesting Facts

Behavior

Male White-tailed Ptarmigan arrive in early spring in breeding areas, where they claim territories with calls and aerial displays. They are highly territorial, confronting other males by raising their colorful eye-combs, lowering their bodies, and running at rivals while making loud, clucking calls. Females, which winter at lower elevations than males over much of the species' range, arrive in breeding areas later than males and inspect displaying males singly or in small groups. To entice females, males perform elaborate courtship displays that involve bowing, pecking at the ground, and parading while fanning, tilting the tail, and spreading the wings, often dragging the wingtips over the ground. A courting male erects the red eye-combs, calls, and usually chases any female that approaches. Territories vary from about 12 acres to as much as 166 acres, but most are 35–70 acres. Females usually nest inside their mate's territory. Females are not as aggressively territorial as females of other ptarmigan species, though they will drive away other females when nesting. Mated pairs stay close together during courtship, and males guard the females until incubation, not allowing other males near. Some males are polygynous (have two or more female partners), and in such cases, the male usually spends more time with the primary partner, typically the older female. Only females incubate, and males play no role in chick defense or rearing (unlike in Willow Ptarmigan). If females lose their first clutch, they often switch to a different mate in the same breeding season. Pair bonds in this species endure for about 3 months per year, and only about 80% of birds re-partner with the same mate as in the previous year, a lower rate than in the larger ptarmigan species. Females usually move with chicks into sheltered areas, where slightly taller vegetation provides cover from predators and a richer environment for both plant and insect foods. After the young fledge, adults in some areas move upslope, to molt into winter plumage at higher elevations. In some cases, they return to breeding territories to feed until winter weather compels them to move downslope.

Conservation

White-tailed Ptarmigan inhabit remote areas that are rarely visited by humans. As a consequence, little is known about their population trends. Partners in Flight estimates a global breeding population of 2 million and rates the species an 11 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. Among the conservation challenges for this species are hunting, overgrazing, heavy metal poisoning (from mines), and habitat damage and alteration (from off-road vehicle traffic, road construction, ski area development, and other sources). Climate change will reduce the extent of their alpine habitats, which are threatened by advancement of shrubs and trees upslope, particularly in the southern part of this species’ range.

Credits

Carey, J. R., and D. S. Judge. (2000). Longevity Records: Life Spans of Mammals, Birds, Amphibians, Reptiles, and Fish. Odense Monographs on Population Aging, No. 8. University Press of Southern Denmark, Odense, Denmark.

Martin, K., Leslie A. Robb, Scott Wilson and Clait E. Braun. (2015). White-tailed Ptarmigan (Lagopus leucura), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Partners in Flight (2017). Avian Conservation Assessment Database. 2017.

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

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