How do changes in habitat and climate affect deer population dynamics and community relationships?


Why answer this question?

Sitka black-tailed deer are a unique subspecies of mule deer, and we know relatively little about them. While researchers have gained insight into habitat selection and nutritional needs of adult female deer from past work, several key aspects of their life history remain poorly understood, especially reproductive success of females and survival of young.These two vital rates are controls of population change over time, and may be affected by habitat, climate, predation, and hunting.

Shifting predation regimes, forest succession in timber harvested areas, and long-term trends in climate and precipitation all have the potential to strongly affect deer. In order to ensure healthy deer populations in Southeast Alaska now and in the future, it is imperative to understand these effects.


Outreach and broader impacts of this work

The importance of this study extends beyond understanding these ecological relationships. Sitka black-tailed deer are a vitally important subsistence resource for human harvest, and many households in rural Southeast Alaska rely on deer meat as a staple in their diets.

Because Sitka black-tailed deer are such a vital component of both the region’s ecology and subsistence hunting lifestyle, we engage in numerous outreach activities in local communities. Our keystone outreach activity is a collaborative venture to develop and teach science curriculum based on our research in partnership with the Southeast Island School District and the Fairbanks School District. This work is funded by the National Science Foundation’s GK-12 program.

In practical, management-oriented terms, this project will increase our understanding of deer population growth rates, habitat requirements, and relationships with climate and predators, allowing us to effectively manage for a healthy, harvestable deer population in the face of environmental change. Balanced deer and predator populations not only contributes to a thriving forest ecosystem, but also enhances the local communities and economy by providing important subsistence and recreational resource and enhancing food security.

What we are focusing on:

  1. Causes of fawn mortality and environmental predictors of fawn survival
  2. Trade-offs between risk and forage access for reproductive female deer
  3. Indirect competition between deer fawns and salmon mediated by black bears
  4. Effects of landscape and habitat on risk, habitat selection, and reproductive success for deer
  5. Winter movement patterns and habitat selection by deer in response to energetics and predation risk
  6. Effects of climate variability and timber harvest regime on deer population dynamics
  7. Restoration tools for timber-harvested landscapes


How are we answering these questions?

We tackle these questions by:

- monitoring individual deer and keeping track of their reproduction, survival, habitat use, and movement.

- We then integrate detailed bear habitat selection and movement data collected in overlapping years and study areas to find out how this omnivorous, highly effective species of predator finds deer and other food resources throughout the year.

- We are also using camera traps and genetic tools to estimate deer density and activity patterns in restored versus un-restored second growth forests. 

This is a cooperative project between the University of Idaho, the US Forest Service, and the Alaska Department of Fish Game. We could not do this work without our agency collaborators.