"The Mt Emily(Oregon) Wolf-Cougar Study is a collaborative effort between the Oregon Department of Fish and Wildlife, the Confederated Tribes of the Umatilla Indian Reservation, and Oregon State University"........... Beginning in 2014 and running through the Summer of 2018, the goal of the project was to determine how Pumas(Cougars) would react to the interspecific competition directed toward them by the newly colonizing Wolves............ "Previous studies have suggested that wolf pack structure provided wolves the advantage in wolf-cougar interactions (i.e. outnumbered), and that the likelihood for wolves to kill cougars is greater than for cougar to kill wolves"..............."However, the effects of competitive interactions with wolves may be limited if cougars exploit alternate prey resources, habitats unoccupied by wolves, or if interactions are rare".............."Thus far in this Mt. Emily region of Oregon, the research team found that Cougars are eating fewer deer since wolves have arrived".........."They(Cougars) are scavenging more and eating smaller prey"............."The number of elk have increased"............."The number of deer have stayed the same".............."Cougars are selecting prey closer to water, deeper in forests, and higher in elevation"..............No question that a ripple effect across this natural system has taken effect----Most likely, as in Yellowstone, the full complement of top-down carnivores restoring optimum biodiversity to the landscape

From: Randy and Pam Comeleo ;rottyler@peak.org;
Date: June 6, 2019 at 11:25:49 AM PDT
To: rick.meril@gmail.com
Subject: Carnivore Competition: Implications of Recolonizing Gray Wolves for Cougar Populations in NE Oregon

Hi Rick,

I was reading your March 24, 2015 post about this study the other day.  I went to Beth Orning's PhD dissertation defense seminar this morning.  The study compared results with a 2009-2012 study of Mt. Emily cougar diet and behavior completed by OSU M.S. student Darren Clark.  Below is a summary of her results.

Since wolves have arrived in the Mt. Emily wildlife management unit:

Lower ungulate kill and biomass intake rates have been measured. Cougar are eating fewer deer since wolves have arrived.  They are scavenging more and eating smaller prey.

• The number of elk in the Mt. Emily unit have increased.
• The number of deer in the Mt. Emily unit have stayed the same.
• Cougars are selecting prey closer to water, deeper in forests, and higher in elevation.

Wolf-Cougar Interactions in Oregon Project Website: https://sites.google.com/site/mtemilywolfcougarstudy/

Randy Comeleo

Corvalli, OR


A female cougar with a malfunctioning GPS collar that was treed
so the collar could be replaced.  The batteries on the GPS collars
have a lifespan of approximately 15 months.  Once the battery
fails the VHF portion of the collar continues to work so that the
researchers are able to still locate the cougar and replace the collar.

 https://sites.google.com/site/mtemilywolfcougarstudy/

Wolf-Cougar Interactions in Oregon 

Populations of large carnivores are expanding across portions of North America, and sympatric wolves and cougars share habitat, home ranges, and prey resources. These coexisting predators may be subject to interspecific competition and direct interactions between large carnivores are challenging to document due to their cryptic behavior and low population densities. 

Previous studies have suggested that wolf pack structure provided wolves the advantage in wolf-cougar interactions (i.e. outnumbered), and that the likelihood for wolves to kill cougars is greater than for cougar to kill wolves. Wolves can steal cougar kills, and occasionally kill adult cougars and cougar kittens, suggesting interactions in favor of wolves, and cougar as the subordinate competitor in wolf-cougar systems. However, the effects of competitive interactions with wolves may be limited if cougars exploit alternate prey resources, habitats unoccupied by wolves, or if interactions are rare.

An adult male wolf GPS collared in the Mt Emily Wildlife Unit of Oregon

We are placing GPS collars on both wolves and cougars in the Mt Emily Wildlife Management Unit to identify competitive interactions, predation rates, and prey selection for wolves and cougars in northeast Oregon. This information will be useful in identifying the effects of both carnivores on ungulate population dynamics in northeast Oregon.

The Mt Emily Wolf-Cougar Study is a collaborative effort between the Oregon Department of Fish and Wildlife, the Confederated Tribes of the Umatilla Indian Reservation, and Oregon State University. The research project began in the winter of 2014 and will conclude in the summer of 2018