Gray wolf restoration in the United States

Translocating the gray wolf (Canis lupus) back to western United States has been an effort of pure difficulty, but also celebration.  Many U.S. citizens feel that this endeavor has been one of the most important accomplishments of our conservation history.  On the other hand, the people that deal with wolves on a daily basis have the opposite view.   Wolves have fit in well ecologically.  They have increased in numbers, less so in the Mexican wolf recovery area, foraged on native prey, and have instigated ecological processes that have been absent from these areas for almost 100 years.  Wolves have also killed livestock, and have in some cases made people living in wolf country uneasy about their presence.

Wolf restoration will continue to be a juggling act between managing sustainable wolf populations and reducing losses due to predation on livestock.  To efficiently and successfully manage ecosystems where wolves and humans coexist, baseline knowledge about wolf impacts on the ecosystem are essential.  For example, we must know, what do wolves eat?  How much do they eat?  Why do their populations go up and down?  And, what is their impact on other species, not just their prey?

My research has focused on wolf interactions with prey and wolf interactions with other carnivores.  I studied Mexican wolf diet in Arizona and New Mexico in summer.  This work has provided a basis for understanding the basic summer diet of Mexican wolves as it relates to natural and domestic prey bases, and was highly necessary because no prior study had focused on summer diet (summer diet may be most important as it relates to livestock).  What we found was that Mexican wolves eat mostly native prey (i.e., elk [Cervus elaphus]), but also eat a small proportion of livestock.

I also studied interspecific interactions between coyotes (Canis latrans) and wolves.  Most of the research on wolf restoration focuses on population dynamics of wolves, and predation.  Little has focused on wolf impacts on other species.  Based on field observation of hundreds of wolf-coyote interactions we analyzed relationships on the characteristics of interactions and their outcomes.  Although wolves do kill coyotes at wolf-killed carcasses, coyotes definitely capitalize on this food source.  In addition, we suggest that coyotes may have been quite naïve to wolves in the first few years after reintroduction as the number of interactions was very high in the early years (Merkle et al. 2009).  All these results provide insight to the extent that wolves have affected the ecosystem since their translocation.

Collaborators: Yellowstone National Park, Mexican Wolf Recovery Team