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The Montana Cooperative Wildlife Research Unit

The University of Montana

Jeffrey Stetz - Ph.D. Candidate - Wildlife Biology

Advisor - Mike Mitchell


Natural Science Building - Room 312

Office Phone - 406-243-4348

Stetz photo

Project Title:

Spatial and temporal scales of population performance in grizzly and black bears in the Northern Continental Divide Ecosystem, Montana


My primary interests are in investigating habitat selection and population performance across the sympatric grizzly and black bear populations in the Northern Continental Divide Ecosystem (NCDE) in the Northern Rocky Mountains of Montana.   I am also interested in evaluating the ability of noninvasive genetic sampling (NGS) to detect fine-scale demographic processes in these populations.  The specific questions that I am currently exploring include:

  1. How does habitat selection vary in space and time for grizzly and black bears in this region?  To answer this, I will use a combination of occupancy modeling and spatial interpolation methods using detection data from noninvasive genetic sampling projects.
  2. How do habitat selection patterns vary between the sympatric grizzly and black bear populations in the NCDE?  I will use the results of Question 1 to identify habitat factors that are shared versus specific to each species.  This answer could inform grizzly bear reintroduction/augmentation programs if we determine that, for example, high black bear densities may lead to reduced grizzly bear density.
  3. Why do we see such dramatic differences in capture probabilities of grizzly bears in certain NGS methods across populations?  I will use detection data from 3-4 distinct populations to model capture probabilities in a meta-analysis framework.  These results could be useful in designing future monitoring programs.
  4. How can we use NGS methods to detect fine scale population performance (i.e., population growth rates)?  I will use simulations with spatially-explicit mark-recapture methods to explore the conditions under which intra-population (e.g., source-sink) dynamics can be identified. 

Progress and Status:

The bulk of the data to be used in my dissertation research was collected in 1998-2000 and 2004 during our two research projects.  I have obtained access to datasets from the Russian Far East, Banff National Park, and Greece for Question 3.  Ongoing research in Montana is in year 3 of 4, with approximately 30 field technicians conducting repeated surveys of over 5,900 sampling sites across nearly 3.6 million ha in the Northern Rockies.  For example, In 2009, our start-up year, 9,200 hair samples were collected, with 258 grizzly bears detected; these numbers will increase each year as more sampling sites are activated.

Natural Sciences Room 205

Missoula, MT 59812