Huntley, B., & Green, R. (2011). Bioclimatic models of the distributions of Gyrfalcons and ptarmigan. In R. Watson, T. Cade, M. Fuller, G. Hunt, & E. Potapov (Eds.), Gyrfalcons and Ptarmigan in a Changing World. The Peregrine Fund. https://doi.org/10.4080/gpcw.2011.0312