• Research Interests
• Research Projects
• CV (pdf)
• Courses:
  Zool 588, Zool 433a,Wildlife Nutrition

Dr. Hellgren is a wildlife ecologist in the Cooperative Wildlife Research Laboratory and Professor in the Department of Zoology, Southern Illinois University. His research interests revolve around questions of population and habitat ecology in primarily mammalian systems.

• Eastern red cedar encroachment in southern Great Plains grasslands: wildlife consequences and management implications
• Patch-level habitat modeling in an urban landscape for a species of concern as a tool for relocation efforts
• Spring habitat settlement by Dickcissels (Spiza americana) and correlates with nest success, fledging success, and site fidelity at an openland site within the Shawnee National Forest, Illinois
• Interspecific interactions between mourning doves (Zenaida marcroura) and Eurasian collared-doves (Streptopelia decaocto) in semi-urban and urban environments in southern Illinois
• Status and Distribution of the State-threatened marsh rice rat in Illinois
• Effects of forest composition on trophic relationships among mast production and mammals in southern Illinois