Brown and black bear density estimation in Alaska using radiotelemetry and replicated mark-resight techniques

摘要: Accurate density and population estimates are needed to manage bear populations but difficult obtain. Most such reported for bears largely subjective lack of precision. Fifteen brown (Ursus arctos) 3 black (U. americanus) were obtained in Alaska during 1985 through 1992 using 2-9 replicates capture-mark-resight (CMR) techniques 17 different areas. Our studies used radiotelemetry document movements marked animals into from search This procedure essentially eliminated the need correct edge or periphery effects caused by absence geographic closure. To estimate size, we a maximum-likelihood estimator modified accommodate temporary our approach permitted direct calculations estimates. procedures provided that repeatable, comparable among areas, included precision, more objective than methods historically abundance. estimation have widespread applicability other wildlife radiotelemetry. within wide spectrum habitats range Alaskan densities 10.1 551 (all ages)/1,000 km 2 89 289 . highest is probably near maximum this species, areas with lower (3.9/1,000 ) been Alaska. Areas higher study occur Brown 6-80 times greater coastal where abundant runs multiple species salmon (Oncorhynchus spp.) available interior CMR technique useful data management impact assessments has potential application