Status of Populations of the White-Tailed Ptarmigan at the Southern Edge of its Range.

—The White-tailed Ptarmigan (Lagopus leucura) is the only ptarmigan species endemic to North America. In New Mexico, the species was first reported from the Sangre de Cristo Mountains in 1865. At a latitude of slightly below 36o N, this location is the extreme southern extent of White-tailed Ptarmigan distribution. Over the next 125 years, the species was reported in New Mexico only occasionally, usually by sheep herders or backpackers. By 1981, it was generally thought that White-tailed Ptarmigan had become extirpated from the state, and a reintroduction was attempted. Regardless of whether the remaining White-tailed Ptarmigan in New Mexico are a result of this reintroduction effort or are indigenous to the state, this remnant population might now be imperiled due to changes in the alpine vegetation and advancing timber lines resulting from climate change. Recent survey efforts have shown that White-tailed Ptarmigan exist in at least two areas in New Mexico, albeit separated by a considerable distance. Received 7 March 2011, accepted 6 June 2011. WOLFE, D. H., L. C. LARSSON, J. R. OLDENETTEL, H. A. WALKER, AND M. A. PATTEN. 2011. Status of populations of the White-tailed Ptarmigan at the southern edge of its range. In R. T. Watson, T. J. Cade, M. Fuller, G. Hunt, and E. Potapov (Eds.). Gyrfalcons and Ptarmigan in a Changing World. The Peregrine Fund, Boise, Idaho, USA. http://dx.doi.org/10.4080/gpcw.2011.0122