Herd organization of cow elk in Custer State Park, South Dakota

Abstract

Understanding herd organization is important when considering management alternatives designed to benefit or manipulate elk (Cervus elaphus) populations. We studied the seasonal and annual herd organization of cow elk in Custer State Park, South Dakota from 1993–1997 by examining seasonal subherd range size, spatial arrangement, overlap, and site fidelity. Based on social interaction analyses, we combined locations of radiocollared cow elk to delineate subherds. We computed 95% kernel home ranges with least‐squares cross validation for each subherd by season and year. Subherd overlap and fidelity by season and year were computed using the Volume of Intersection Index (VI) statistic. We identified 5 relatively discrete, resident cow‐calf subherds. We observed little overlap in utilization distributions of adjacent subherds. The mean VI score across all subherds and time points (n=140) was 0.06 (SE=0.009), indicating an average 6% overlap in subherd area utilization. Subherd overlap between pairs was 0.08 in fall (SE=0.021), 0.06 in winter (SE=0.018), 0.06 in spring (SE=0.2), and 0.05 in summer (SE=0.016). Range sizes were not different between any pairs of seasons or years (F13,52=0.7, P=0.75). Subherd fidelity ranged from 0.41 (SE=0.033) to 0.60 (SE=0.018) overall, indicating differential use within the subherd boundary across years. The ability to distinguish discrete cow‐calf subherd units is consistent with other studies and may aid elk management in Custer State Park. However, use patterns within subherd boundaries were inconsistent across years and may reflect human disturbances (e.g., hunting and logging activities), differences in our sampling approach, or changes in matriarchal leadership. Further evaluation into factors affecting space‐use patterns is necessary to predict changes in range use within the subherd boundary.

The geography of conflict between elk and agricultural values in the Cypress Hills, Canada

“…Our results are consistent with observations for Cervus elaphus populations in other areas, where females were also organized into relatively discrete units (Edge et al, 1986;Coulson et al, 1997;Millspaugh et al, 2004). Six subpopulations were defined using a combination of cluster analysis, home range mapping, and closure assessment.…”

“…They proposed female elk herd ranges as the basic unit for managing non-migratory populations. Home range size is a result of social organization (Millspaugh et al, 2004) and individual movements in relation to resource abundance (Anderson et al, 2005). Female and juvenile elk are gregarious, forming groups exhibiting high fidelity to specific home ranges in non-migratory populations (Edge et al, 1986;Coulson et al, 1997;Millspaugh et al, 2004).…”

Density-Dependent Effects on Group Size Are Sex-Specific in a Gregarious Ungulate

“…Describing general mechanisms of change in group size related to density is critical, however, it does not reveal among which groups these changes occur. Here we assume a random Brownian model of animal movements within a finite area [28]; decreased spacing among individuals with increased density [29]; and the regular intergroup fusions known to occur among elk [30]. Given these constraints we expected to observe either more large groups with no change in dispersion (prediction 3a, [6]) or more small but less dispersed groups (prediction 3b, [4]) as population density increased.…”

Evaluating the individuality of animal‐habitat relationships

“…While the scope of our inferences is restricted to this population of elk in Missouri, we find the extent of the variation that we observed to be applicable to other systems and other species. As elk are highly gregarious and often expected to respond similarly to the environment (Haydon et al., ; Millspaugh, Brundige, Gitzen, & Raedeke, ; Vander Wal, Laforge, & McLoughlin, ), the individual variation in our analysis may be conservative when compared to other species of wildlife residing in other systems. In this way, the results of our analysis are consistent with an array of recent research demonstrating profound individuality in animal‐habitat relationships for a number of wildlife species (Bonnot et al., ; Réale et al., ; Spiegel et al., ).…”