Lagopus leucurawhite-tailed ptarmigan

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Geographic Range

South-central Alaska to northern New Mexico, North America: Lagopus leucura is the only ptarmigan species found south of Canada. It inhabits a harsh environment, characterized by cold, alpine tundra. During the winter, this species resides along stream banks and in high basins above or near timberline areas where willow (Salix sp.) is abundant.

(Encyclopedia Britannica Online, Utah Division of Wildlife Resources 1997)

Habitat

Winter Habitat: Because willow is so integral to the diet of L. leucura during the winter months, this species generally inhabits areas where willow growth is visible above the snow (along steam beds), or where it has been exposed by wind action.

Breeding Habitat: Both males and females are found on breeding territories in alpine areas above timberline from early May until late June. These territories are characterized by areas where the snow has melted, and willow abundance and proximity to water. For instance, a breeding territory is typically found at an exposed spot at the base of a talus slope, or a windswept saddle or knoll. Research has shown that territories are in areas of tall (>30 cm) willow shrubs and contain more subshrub, moss, and boulder cover than in non-breeding areas. During breeding, L. leucura uses topographic depressions for its nests.

Brood-Rearing Habitat: Hens occupy moist meadows, and flocks are found in areas replete with boulders, in the summer brood-rearing habitat. (This habitat is found at higher elevations than the breeding territories.) Rich vegetation, particularly that found around springs, heads of streams, or below a slow-melting snowfield, is crucial for a brood-rearing area. L. leucura will stay here until it is forced to lower elevations by winter weather.

(Utah Division of Wildlife Resources 1997,

Frederick and Gutierrez 1992)

Physical Description

Total Length: 30 to 31 cm.

L. leucura is the most petite member of the Tetraonidae family in North America. It is a medium-sized, round-shaped bird whose distinguishing characteristics include: distinct white tail feathers (rectrices) in adults; a small black bill; and feet and legs covered by stiff feathers. The white rectrices differentiate this species from all other ptarmigan species, which have black rectrices. Its heavily feathered legs help to create a "snowshoe" effect, aiding locomotion on snow. Another distinctive trait of the white-tailed ptarmigan is the change of its plumage with the seasons-it molts almost continually from late April to early November. In the spring, summer, and fall, this species assumes a mottled brown-gray coloration, with a white tail and outer wing feathers; in the winter it turns completely white, except for the beak, eye and eye comb, and claws. Thus, L. leucura blends in nearly perfectly with its highly varied surroundings both in the summer and winter.

Males and females only differ slightly in body size, shape, and winter plumage. During breeding season males can be identified by crimson eye combs over (these combs are most prominent during breeding season), and black and white barring on the breast. Females on the other hand, have smaller, pinkish colored eye combs, and they have brown and black plumage with yellow barring.

(Braun et al. 1993, Dickinson 2000, USGS Patuxent Wildlife Research Center 1997, WFSC)

  • Range mass
    350 to 425 g
    12.33 to 14.98 oz

Reproduction

Females are yearlings when they breed. They take responsibility for building nests, which they loosely construct out of dried vegetation. Females have one brood per season and lay four to seven faintly spotted eggs that measure 43 x 29 mm. The length of incubation lasts from 22 to 24 days.

The reproductive season of L. leucura begins in early spring when males display within groups; later, they disperse to their own breeding territories at higher elevations. Here, they form pairs with females. The new pair remains on this territory until the female begins to lay her eggs in mid- to late June. Soon after the eggs have hatched mid- to late July, the female and her brood join the male who has already settled at higher elevations for the summer.

(Ehrlich et al. 1988, Rennicke 1996,

Utah Division of Wildlife Resources 1997)

Behavior

In order to survive in a harsh alpine environment, L. leucura has evolved to withstand a wide range of temperatures in an energy efficient manner. For example, it is more apt to walk than to fly. Also, it finds protection in microhabitats-rock piles, or during severe weather, pockets under the snow-that are several degrees warmer than the surrounding temperature. L. leucura also uses these microhabitats as refuge from its predators, including prairie falcon (Falco mexicanus), golden eagle (Aquila chrysaetos), red fox (Vulpes vulpes), and coyote (Canis latrans). The call of L. leucura is distinguished by soft, low hoots. The range of its calls can be heard on its territories, where it rears its brood, and in late summer and winter flocks. Winter flocks range from 2 to 80 individuals.

L. leucura is generally a monogamous species, but polygyny has been observed. Females and males remain paired for up to three months during the breeding season; however, if members of the pair return for the next season, they will restore their bond and tend to inhabit the same area in successive years. Both sexes guard territories during the breeding season. Males typically engage in ground and aerial pursuits to ward off other male intruders early in the breeding season. They run with an inflexible stride and keep low to the ground; expose eye combs; and give off a strident cackling call. In a standing position, males stand tall and move their head from one side to another. Females may also emit a strident call (flight scream) if they run into another hen during the incubation period. Patterns of male vigilance have been identified in L. leucura when a pair is together before incubation begins. Research has shown that male vigilance enables females to expend less energy on looking out for predators and more on foraging that will allow them to secure the energy they require for egg laying. Finally, research has shown males to have high philopatry, while female disperse farther.

(Artiss and Martin 1995, Braun et al. 1993, Dickinson 2000, Giesen and Braun 1993a, Giesen and Braun 1993b)

Communication and Perception

Food Habits

The diet of L. leucura consists primarily of plant matter, including willow buds and leaves, flowers, berries, and lichens. In the winter, willow is key to the white-tailed ptarmigan's survival: willow buds and twigs provide its only source of food. This species also feeds on insects during this season, but to a lesser degree. Following the hatching of chicks (in mid- to late July), females remain and eat vegetation that is still green, such as Geum, Carex, and Polygonum. Lagopus leucura also ingests grit in order to aid in digesting course foods.

(Braun et al. 1993, Utah Division of Wildlife Resources 1997)

Economic Importance for Humans: Positive

L. leucura may be hunted. It has been shown, however, that reduced breeding densities as well as a lower average age of birds that breed are common in populations that have been over-hunted.

(Braun et al. 1993)

Conservation Status

This species is not endangered. It is harbored in US protected areas, such as Rocky Mountain National Park in Colorado. Because its habitat is still more or less undisturbed, the historic range of this species has been preserved. Nonetheless, L. leucura has not entirely escaped human activities. Today, road construction, mining, all-terrain vehicles, and ski area development, just to name a few, decrease the amount of food available to L. leucura during the winter.

Braun et al. 1993, MacDonald 2000)

Other Comments

L. Leucurus has been successfully introduced into to the central High Sierra and in the Uinta Mountains in Utah. It has also been introduced into the Wallowa Mountains (Oregon), Pikes Peak (Colorado), and has been reintroduced into the Pecos Wilderness Area (New Mexico).

(Dickinson 2000, Braun et al. 1993)

Contributors

Stephanie Hitztaler (author), University of Michigan-Ann Arbor, Terry Root (editor), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

tundra

A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.

visual

uses sight to communicate

References

"Encyclopedia Britannica Online. White-tailed Ptarmigan" (On-line). Accessed September 2000 at http://members.eb.com/bol/topic?tmap_id=170250000&tmap_typ=dx&pm=1.

Artiss, J., K. Martin. 1995. Male vigilance in white-tailed ptarmigan, Lagopus leucurus: mate guarding or predator detection?. Animal Behaviour, 49(5): 1249-1258.

Braun, C., K. Martin, L. Robb. 1993. White-tailed ptarmigan (Lagopus leucurus). Birds of North America, 68: 1-22.

Dickinson, M. 2000. Field Guide to the Birds of North America. Third Edition.. Washington D.C: National Geographic Society.

Ehrlich, P., D. Dobkin, D. Wheye. 1988. The Birders Handbook: A Field Guide to the Natural History of North American Birds.. New York: Simon and Schuster Inc..

Frederick, G., R. Gutierrez. 1992. Habitat use and population characteristics of the white-tailed ptarmigan in the Sierra Nevada, California. Condor, 94(4): 889-902.

Giesen, K., C. Braun. 1993. Natal dispersal and recruitment of juvenile white-tailed ptarmigan in Colorado. Journal of Wildlife Management, 57 (1): 72-77.

Giesen, K., C. Braun. 1992. Winter home range and habitat characteristics of White-tailed ptarmigan in Colorado. Wilson Bulletin, 104 (2): 263-272.

MacDonald, T. 2000. "Colorado Hotspots. North American Endemic Specialties in Colorado" (On-line). Accessed September 2000 at http://www.camacdonald.com/birding/uscolorado.htm.

Rennicke, J. 1996. Colorado Wildlife. Helena, Mont: Falcon Press Pub. Co.

USGS Patuxent Wildlife Research Center, 1997. "White-tailed ptarmigan Lagopus leucurus" (On-line). Accessed September 2000 at http://www.mbr.nbs.gov/id/htmid/h3040id.html.

Utah Division of Wildlife Resources, 1997. "Guidelines for Locating White-tailed Ptarmigan in the Uinta Mountains" (On-line). Accessed September 2000 at http://www.nr.state.ut.us/dwr/wtptarm.htm.

WFSC, "White-tailed ptarmigan" (On-line). Accessed September 2000 at http://apc.tamu.edu/wfsc408/images2/ugb18.htm.