Elk presence inside various-sized cattle exclosures

Accurate measures of the relative resource impacts from elk (Cervus elaphus) and cattle (Bos taurus and B. indicus) improve land management planning wherever these species cohabitate. Comparisons of utilization inside and outside cattle exclosures are often used for this purpose. The objectives of our study were to determine if (1) elk presence differed inside and adjacent to several different-sized cattle exclosures; (2) there was a relationship between cattle exclosure size and elk presence in exclosures; and (3) a minimum cattle exclosure size is appropriate for assessing elk impacts. Seven different-sized cattle exclosures (4.00, 2.00, 1.00, 0.50, 0.25, 0.10, and 0.05 ha) were compared in western Montana during the spring of 1996 and 1997. Trackplots (1-m2 areas cleared of vegetation) were used to detect elk presence. Chi-square tests indicated elk presence inside all exclosures was less (P < 0.10) than elk presence adjacent to the exclosures. Regression analysis indicated exclosure size and elk presence were correlated (P < 0.03). Elk presence inside exclosures increased with increasing exclosure size. Our results did not support the minimum exclosure size (0.4 ha) recommended in the literature. Cattle exclosures larger than 4 ha appear needed to accurately measure relative resource impacts from elk and cattle; however, this does not ensure that an exclosure > 4.0 ha in size will solve all of the problems associated with this technique.