Female elk contacts are neither frequency nor density dependent

Ecology
By: , and 

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Abstract

Identifying drivers of contact rates among individuals is critical to understanding disease dynamics and implementing targeted control measures. We studied the interaction patterns of 149 female elk (Cervus canadensis) distributed across five different regions of western Wyoming over three years, defining a contact as an approach within one body length (∼2 m). Using hierarchical models that account for correlations within individuals, pairs, and groups, we found that pairwise contact rates within a group declined by a factor of three as group sizes increased 33-fold. Per capita contact rates, however, increased with group size according to a power function, such that female elk contact rates fell in between the predictions of density- or frequency-dependent disease models. We found similar patterns for the duration of contacts. Our results suggest that larger elk groups are likely to play a disproportionate role in the disease dynamics of directly transmitted infections in elk. Supplemental feeding of elk had a limited impact on pairwise interaction rates and durations, but per capita rates were more than two times higher on feeding grounds. Our statistical approach decomposes the variation in contact rate into individual, dyadic, and environmental effects, and provides insight into factors that may be targeted by disease control programs. In particular, female elk contact patterns were driven more by environmental factors such as group size than by either individual or dyad effects.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Female elk contacts are neither frequency nor density dependent
Series title Ecology
DOI 10.1890/12-2086.1
Volume 94
Issue 9
Year Published 2013
Language English
Publisher Ecological Society of America
Contributing office(s) Northern Rocky Mountain Science Center
Description 11 p.
First page 2076
Last page 2086
Country United States
State Wyoming
Other Geospatial Greater Yellowstone Ecosystem
Online Only (Y/N) N
Additional Online Files (Y/N) N