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Bark Beetle Research
Bark Beetle Research

​Mammal and Breeding Bird Response to Bark Beetle Outbreaks

Led By

Jake Ivan

Study Area


Project Status


Research Objective

  • To determine how bark beetle outbreaks have impacted breeding birds and mammals in Colorado.

Wildlife Cameras

As part of a project to learn about the impacts of bark beetle outbreaks on wildlife, Colorado Parks and Wildlife deployed 300 remote wildlife cameras at randomly selected locations throughout spruce/fir and lodgepole pine forests in Colorado.  Below is a sample of the almost 400,000 photos collected from the project.

Project Description

Since 1996, millions of acres of Colorado forests have fallen victim to bark beetle infestations. This unusual epidemic has left researchers wondering how local wildlife living in these forests will respond.

This study will focus on tracking how mammals and breeding birds alter their use of subalpine forests during the course of an outbreak. 

Researchers expect wildlife response to the beetle epidemic to vary by species and forest system. Some species may stay in the area during the full course of the outbreak, while others may disappear once the area is infected. For example, researchers expect red squirrel use of lodgepole pine forests to decrease as the outbreak affects cone-producing trees, which serve as the squirrel's primary food source. 

The focal species for this study are those listed as a priority species under the Colorado Wildlife Action Plan and/or listed as sensitive species by the United State Forest Service Region 2 and/or listed as vulnerable at the sub-national scale by NatureServ. 

These species include:

  • American marten
  • American Three-toed Woodpecker
  • Broad-tailed Hummingbird
  • Cassin's Finch
  • Cordilleran Flycatcher
  • Dusky Flycatcher
  • Dusky Grouse
  • Evening Grosbeak
  • Northern Goshawk
  • Olive-sided Flycatcher
  • Red Crossbill
  • Red-naped Sapsucker
  • Williamson's Sapsucker

Two additional species, the snowshoe hare and red squirrel, are focal species as well because together they compromise nearly 100 percent of the diet of the Canada lynx, which is a state and federally listed species.  

Researchers plan to survey the selected mammal species using motion-sensor cameras. Bird species will be surveyed during early morning counts throughout the breeding season (late May to early July). Because the survey methods are general, researchers should be able to gather information about variety of additional game and non-game species beyond those species of concern listed above. Researchers will use this data to determine which species decrease their use of these forests as bark beetle infestations run their course, which species increase their use, and which species are unaffected.

Associated Publications

Ivan, J. S. 2013. Small mammal and breeding bird response to bark beetle outbreaks in Colorado. Pages 1-13 in Wildlife Research Report, Mammals Research Program, Colorado Division of Parks and Wildlife, Fort Collins, CO. 310 pp.