Meet the Team

Mark Ditmer.

Mark Ditmer, PhD

Quantitative Research Ecologist
Rocky Mountain Research Station at U.S. Forest Service 
Fort Collins, Colorado, United States
Faculty Affiliate | Colorado State University
Graduate Degree Program in Ecology, Department of Fisheries, Wildlife, and Conservation Biology

Mark completed his PhD at the University of Minnesota in 2014 studying how American black bear movements, diet and physiology are influenced by habitat fragmentation in a largely agricultural region. His current research, for the Minnesota Zoo, is studying how moose movement and habitat selection are influenced by wolves. Additionally, he is continuing his previous research utilizing cardiac biologgers, inserted in bears subcutaneously in conjunction with GPS-collars, to better understand causes of stress in wildlife (e.g., road crossings, drones).

Dave Garshelis standing in the snow.

Dave Garshelis, PhD

Chair of the IUCN’s Bear Specialist Group; 
Retired DNR, Bear Project Leader for 37 years

Dave Garshelis' research during the past decade involves bears and sea otters, although his interests are not limited to these species. He is broadly interested in developing methods for monitoring population status (size, trends, limiting factors), implementing such monitoring programs, and utilizing results to develop management or conservation strategies. As a research biologist for the Minnesota Department of Natural Resources, Dave has been able to directly apply the population monitoring approaches for black bears that were developed through his research, and then utilize the results to effect appropriate management strategies.

Paul Iaizzo doing a health check on hibernating bear.

Paul Iaizzo, PhD

Professor of Surgery, Integrative Biology and Physiology and the Carlson School of Management, University of Minnesota, Associate Director for the Institute of Engineering in Medicine; Distinguished University Teaching Professor; Medtronic Professor of Visible Heart Research; Director, Malignant Hyperthermia Muscle Biopsy Center

Paul Iaizzo's primary research focus is translational systems physiology, and his research group has developed a unique isolated working large mammalian heart model. The Visible Heart Laboratory is well known for its novel imaging techniques of cardiac anatomy and physiology, and is an ideal place to perform translational systems physiology research. Other research interests include cardiac pacing, skeletal muscle pathophysiology, thermoregulation, black bear hibernation, wound healing, and spine biomechanics. Paul has authored more than 260 original articles, edited 7 books, and holds multiple patents (both U.S. and European) related to cardiac anatomy, physiology, and devices.

Tim Laske holding four baby bears.

Tim Laske, PhD

Vice President of Research and Business Development, Medtronic Cardiac Ablation Solutions; Adjunct Professor, Department of Surgery, University of Minnesota

Tim Laske currently has responsibilities in Research, Intellectual Property and Business Development for cardiac ablation products and systems at Medtronic. His previous roles during his 28 years at Medtronic included Vice President of Product Development for AF Solutions, Senior Director of Heart Valve Product Development, Senior Program Director for Transcatheter Heart Valves, Technology Director for Therapy Delivery in Cardiac Rhythm Disease Management, and technology management and design engineering positions in Tachyarrhythmia Lead Development. Prior to Medtronic, Tim worked as a Design Engineer at Ford Motor Company in Crash Safety and Advanced Vehicle Systems Engineering.

Hannah Leeper holding four baby bears.

Hannah Leeper, MS

Research Wildlife Biologist, Minnesota Department of Natural Resources

Hannah finished her MS degree in Fish Wildlife and Conservation Biology at the University of Minnesota. 

Andrew Tri weighing a hibernation baby bear.

Andrew Tri, PhD, CWB®, CWT®

Minnesota Bear Project Team Leader, Research Wildlife Biologist, Minnesota Department of Natural Resources, Adjunct Assistant Professor, Texas A&M University–Kingsville

Andrew Tri’s research emphasis has been on the ecology and management of game species in the US and Mexico (American Black Bear, upland game birds, and ungulates). He is interested in population dynamics, spatial ecology, and incorporating the quantitative methods into an adaptive management framework.