Coyote and wolf interactions
by Cat Urbigkit, Pinedale Online!
June 25, 2009
Researchers studying coyote and wolf interactions in Yellowstone National Park have published results in the Canadian Journal of Zoology.
In "Interference competition between gray wolves and coyotes in Yellowstone National Park," J. Merkle, D. Stahler and D. Smith write in the abstract:
"Factors influencing the outcome of interspecific interactions between sympatric carnivores, along with population-level consequences, are not clearly understood. The reintroduction of gray wolves (Canis lupus L., 1758) to Yellowstone National Park provides a rare opportunity to study interactions with coyotes (Canis latrans Say, 1823), which had lived in the absence of wolves for >60 years.
"We evaluated direct interactions between wolves and coyotes to identify factors influencing the outcomes of interspecific interactions and describe the context and degree of competition and coexistence. Using radio-collared wolves, we documented 337 wolf - coyote interactions from 1995 to 2007.
"The majority (75%) of interactions occurred at ungulate-carcass sites. Wolves initiated the majority of encounters (85%), generally outnumbered coyotes (39%), and dominated (91%) most interactions.
"Wolves typically (79%) chased coyotes without physical contact; however, 25 interactions (7%) resulted in a coyote death. Interactions decreased over time, suggesting coyote adaptation or a decline in coyote density. In the majority (80%) of fatal interactions, wolves outnumbered coyotes. However, wolves did not outnumber coyotes in interactions (n = 18) where coyotes chased or attacked/harassed wolves.
"Our results suggest that wolves are the dominant canid, group size may influence the outcome of interactions, and coyotes must benefit from the access to carrion at wolf-killed carcasses."
2009, Canadian Journal of Zoology 87: 56-63