Effects of Petroleum Exploration on Woodland Caribou in Northeastern Alberta

Woodland caribou (Rangifer tarandus caribou) in northeastern Alberta apparently have declined and are classified as endangered. Petroleum exploration has been implicated as a possible cause. We examined the effects of simulated petroleum exploration (i.e., loud noise) on caribou movement and behavior. We monitored 5 (1993) and 20 (1994) radiocollared caribou during 3 periods (pretest, test, and post-test) over 2 treatments (exposed and control). Exposed caribou moved significantly faster than control caribou (2.3 + 0.2 SE vs. 1.6 km/hr + 0.1), but not significantly farther. Exposed caribou crossed habitat boundaries significantly more than did controls (0.53 t 0.16 vs. 0.27 changes/period ? 0.14). Disturbance did not affect significantly the proportion of time allocated to feeding. Treatment caribou demonstrated higher overall movement rates in 1993 than 1994 (2.7 ? 0.2 vs. 1.7 km/hr + 0.1), displacement (3.5 _ 1.3 vs. 2.3 km + 0.6), and more time allocated to feeding (27.5 + 2.9 vs. 9.0% -? 1.7). Habitat boundaries crossed did not differ significantly between years. We suggest that increased movement may result in higher energy expenditure during winter, and that disturbed caribou may switch habitat type for cover or escape terrain. We believe that differences in movement between years resulted from higher snow depths in 1994. We also suggest that land-use managers should limit total disturbance during winter rather than mitigate industrial activity with timing restrictions.