Research Interests

I am broadly trained in biology and zoology and specifically trained in wildlife ecology.  My research interests lie primarily in the areas of population ecology and behavior, especially of mammals.  I have a great interest in the prairie ecosystem and have a number of research projects on prairie species.  This is a list of some of my past and current research projects.  In the event I have interested students, some of the past projects could be continued again..

Bison (Bison bison) Population Ecology and Breeding Behavior

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Bull tending a cow with her calf at
Halliday Well Prairie Dog Town in
Theodore Roosevelt National Park.

We are studying the bison herd at Theodore Roosevelt National Park near Medora, North Dakota.  We are interested in herd composition especially as it relates to bull:cow ratios and calf production.  In the past, park personnel have been concerned that the herd perhaps had too many bulls.  We have also been studying behavior during the breeding season to help us determine optimal bull:cow ratios.  The information that we gather will be used by the park in making recommendations for future bison round-ups where a portion of the herd is removed.

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Located in the Badlands, the park is home to other large mammal species including antelope, mule deer, white-tailed deer, and wild (feral) horses.  A number of MSUM students have participated in this study since it began in 1998.  Students gain experience not only in recording bison behavior and herd composition, but they also learn camping skills because we camp while doing the research. 

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Feral foal in Theodore Roosevelt National Park.

Black-tailed Prairie Dog (Cynomys ludovicianus) Ecology in North Dakota

While studying the bison in Theodore Roosevelt National Park, we sometimes also incidentally study the prairie dogs.  Currently, our efforts are limited to gathering material for future DNA studies and occasional live-trapping.  

Black-tailed prairie dog in Theodore Roosevelt National Park.


Gunnison's Prairie Dog (Cynomys gunnisoni) Ecology in Colorado

This study ran primarily between 1991 and 1997, but I and my research students are now analyzing different portions of the huge data set to answer various ecological and behavioral questions.  At this time, we are looking primarily at survival in prairie dogs and also using a GIS (Geographic Information System) to analyze spatial use in a prairie dog colony.



Donna Bruns Stockrahm gathering radiotelemetry data from collared prairie dogs on her study site northwest of Pagosa Springs, Colorado.

In the past, we collected DNA samples (in blood) to look at genetic relationships of prairie dogs in the colony.  In the future, we hope to use our frozen samples to refine our techniques and further examine prairie dog relationships.


Small Mammal Ecology in Western Minnesota Grasslands

We have conducted considerable amounts of live-trapping in western Minnesota to study rare small mammals.  We have concentrated our efforts on the prairie vole (Microtus ochrogaster) which is on Minnesota's list of "Special Concern Species" and the northern grasshopper mouse (Onychomys leucogaster) which is a carnivorous mouse.  Interestingly enough, both of these species are monogamous in their breeding habits.

Prairie vole at Bicentennial Prairie in Clay County, Minnesota.

On an experimental basis, we have also used radio telemetry to monitor movements of the grasshopper mouse.

Northern grasshopper mouse from Ames Gravel Quarry in Clay County, Minnesota.

MSUM research student Lowell Schmitz gathering radiotelemetry data on collared northern grasshopper mice at Ames Gravel Quarry in Clay County, Minnesota.

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Donna Bruns Stockrahm and MSUM research student Lowell Schmitz with small mammal poster.

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Tree Squirrel Ecology in Minnesota Forests

In some of the burr oak forests in Clay County, four species of tree squirrels coexist:  gray (Sciurus carolinensis), fox (S. niger), red (Tamiasciurus hudsonicus), and northern flying squirrels (Glaucomys sabrinus).  In the past we have conducted live-trapping studies to investigate how the species partition the habitat allowing coexistence

MSUM research student Jacquie Gerads live-trapping tree squirrels in Clay County, Minnesota.


Burrowing Owl (Athene cunicularia) Ecology

Several years ago, we conducted a survey of Billings County, North Dakota, to assess how many burrowing owls existed on the black-tailed prairie dog colonies which is one of their prime habitats. We also collected data on the characteristics of the burrows that they preferred to inhabit.   We found that numbers have declined drastically in recent years for this often diurnal bird of prey.  


Turtle Ecology and Behavior

This is a new study which will begin in the spring of 2001.  Female painted turtles ( Chrysemys picta) will be fitted with radio transmitters and movements and nesting locations will be monitored.  Data will be collected on characteristics of the nesting sites and also on the level and kind of human use of the nesting areas.

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Female painted turtle with her attached radiotransmitter and antenna.

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MSUM research students Candy Zemlicka and Just Haugen measuring turtles on 5 August 2001.

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Variation in the color of painted turtles taken from wetlands near Rollag, MN, on 5 August 2001.

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