Attributes / relations provided by
♦ ¹Prey Abundance, Space Use, Demography, and Foraging Habitat of Northern Goshawks in Western Washington, Thomas David Bloxton, Jr., University of Washington 2002
♦ ²Exploring the Denali Food Web, ParkWise, National Park Service
♦ ³Martes zibellina (Carnivora: Mustelidae), VLADIMIR G. MONAKHOV, MAMMALIAN SPECIES 43(876):75–86 (2011)
♦ ⁴The plateau pika (Ochotona curzoniae) is a keystone species for biodiversity on the Tibetan plateau, Andrew T. Smith and J. Marc Foggin, Animal Conservation (1999) 2, 235–240
♦ ⁵Spermophilus columbianus, Charles L. Elliott and Jerran T. Flinders, MAMMALIAN SPECIES No. 372, pp. 1-9 (1991)