The Southern Interior Mule Deer Project is World-Class Research

The Southern Interior Mule Deer & Cougar Projects

The Southern Interior Mule Deer (SIMdeer) project is studying the decline of the mule deer across 30,000 square kilometres of the southern Interior to better understand changes in the population, their health, movements, and predators. The study has collared hundreds of mule deer neonates, fawns and does, and has amassed 2.5 million images from 250 cameras in the summer and winter ranges of the region’s mule deer population.

The BCWF is pursuing this world-class mule deer research in collaboration with the Okanagan Nation Alliance, Bonaparte First Nation, The University of British Columbia Okanagan, The University of Idaho and the British Columbia Fish and Wildlife Branch. UBC PhD candidate Chloe Wright and University of Idaho PhD candidate Sam Foster are leading the project.

Chloe and Sam will determine how factors like wildfires, logging, roads, and people influence the distribution and migration patterns of mule deer, as well as the strength of interactions between mule deer and the species that eat or compete with them. The cameras also capture images of wolves, bears, and cougars to help researchers to understand mortality risk and the impact of features, such as roads and trails, that may affect mule deer survival.

The Southern B.C. Cougar Project is led by PhD student Siobhan Darlington, supervisors Dr. Adam Ford and Dr. Karen Hodges, and wildlife biologists TJ Gooliaff and Patrick Stent of the Ministry of Forests, in partnership with the Okanagan Nation Alliance.

The objectives of the study include analyzing cougar kill rates and diet composition where mule deer and bighorn sheep are in decline, quantifying cougar population response to hunter harvest, and analyzing individual cougar response to land use change from forestry and wildfire.

Mule Deer Research

Mule deer populations across much of southern British Columbia are declining, and the causes are not clear due to multiple stressors including resource extraction, wildfires, increasing human development and changing predator densities. To help determine which mechanisms are driving deer populations in southern B.C., we began a large-scale, collaborative research project in March 2018. To date the project has collared 201 adult female deer, 272 juvenile (6-month-old) deer, and 135 neonatal deer (< 1 week old at capture) across three study areas (Boundary, West Okanagan, and Cache Creek).

The study has looked at the annual survival rate of collared deer, and determined the major cause of mortality has been predation (cougars, bears, and coyotes). Of the deer we collared that lived long enough to potentially migrate, 74 per cent were migratory, travelling an average of 47.2 km per year.

The Mule Deer research is being led by Chloe Wright, PhD Candidate, University of British Columbia, Okanagan Campus.

The Camera Project

The camera project is focused on gathering evidence to better understand how B.C.’s changing landscapes, and our presence on them, can influence the distribution of mule deer and their interactions with other wildlife species. To address the current knowledge gap, the camera project team has established 250 camera sites across 30,000 km2 of mule deer country in B.C.’s southern Interior.

Since the summer of 2019, more than 2.5 million images have been collected. This great success is a direct reflection of the hard work and dedication of roughly 325 citizen scientists, many of them BCWF members. About 150 people have put boots on the ground to help maintain the camera grids, and another team of 175 citizen scientists is now sorting through the image collection.

Photo reviewers apply cutting-edge technology to rapidly sort and label wildlife images (; however, at the scale of millions of images, this work still takes some time. There are about 1.2 million images left to catalogue

In addition to the deer, the cameras frequently capture images of predators such as wolves, bears and cougars, especially in areas with industrial access roads and skidding tracks leftover from logging.

While data processing is still underway, the team has already observed 26 different mammal species, including several species of conservation concern in B.C., and have identified nearly 250,000 images of mule deer, the target species. From preliminary analyses, mule deer have the greatest relative abundance of any mammal species in the Bonaparte and West Okanagan regions, both in the summer and winter seasons. (Abundance is calculated by counting camera detections divided by the number of days camera traps were deployed.)

However, moving east into the Boundary region, white-tailed deer relative abundance exceeds that of mule deer in the summer and winter. A wide variety of predators have been captured on camera, the most common being coyotes, black bears, and humans. More results will be released in the coming year as the team translates images into data and begins to explore relationships among mule deer, other wildlife species, and B.C.’s changing landscapes.

If you are interested in helping with this effort, please email Sam:

The Southern B.C. Cougar Project

The Southern B.C. Cougar project aims to address key knowledge gaps in cougar ecology in British Columbia’s southern Interior.

The Cougar project is supported by the Habitat Conservation Trust Foundation, the British Columbia Conservation Foundation, the National Science and Engineering Research Council, Innovation Canada, the Okanagan chapter of the B.C. Wildlife Federation, the Okanagan Nation Alliance and local clubs and volunteers.

From December 2019 to December 2022 the team has GPS-collared 47 individual cougars (33 females, 14 males) and confirmed 870 cougar kills to understand the seasonal habitat use and diet of cougars. The team is further monitoring reproductive success and survival of kittens and have ear-tagged 30 kittens in 14 litters to date.

More information can be found at

Southern Interior Mule Deer Project Webinars

May 24, 2023

March 30, 2022

January 26, 2021

November 10, 2020

News about the Southern Interior Mule Deer Project


Partners of the Southern Interior Mule Deer Project include: