Chairman, Division of Natural Science; Professor of Natural Science
BA, MA Biology, San Francisco State University
PhD Biology, University of Nevada
Research interests: Population biology, behavioral ecology, population dynamics of beavers
In 1996 Professor Busher won the Peyton Richter Award for interdisciplinary teaching.
My research interests are in the general area of mammalian behavioral ecology. I have studied and continue to study the population dynamics and behavior of the North American beaver, Castor canadensis. I am particularly interested in better understanding how populations grow, develop, stabilize, and decline without human exploitation. Beavers represent a fascinating species to study in light of the current conservation biology movement. Beavers in most—if not all—North American locations are expanding in both numbers and range. This expansion comes after extirpation in many regions. Beavers are considered keystone species in their wetland habitats and their activities increase the amount of wetlands. Since wetlands are one of the most endangered—if not the most endangered—habitats in North America, beaver activities should be viewed as positive. However, the increasing number of beavers and their use and expansion of development of their preferred habitat also bring them into conflict for land use with humans. Thus, beavers present a thorny conservation biology problem. Most, if not all, North American populations are not endangered (in fact they are often considered a nuisance), yet they are helping to expand and structure critical, endangered habitat.
By studying natality, group structure, age-specific survivorship, and dispersal in unexploited populations, I hope to be able to predict how populations that are and may be exploited by humans will respond. Beavers are rapidly becoming a political species since their activities can and do affect human land use. For example, in Massachusetts the beaver population is rapidly expanding and beaver-human conflicts over land use result. Beaver control is both a city/town issue and a state issue. While my research is not directly related to developing beaver policy, my knowledge of beaver population biology does draw me into the debate. I was recently nominated (unsuccessfully) to serve on the Fisheries and Wildlife Board in Massachusetts. This board, which is appointed by the governor, sets and implements wildlife policy in the state. Thus, while my research is oriented around fundamental questions in population biology, I am also involved in broader issues of wildlife policy development.
In Europe and Asia beaver conservation is also becoming a major issue. Beavers (the Eurasian species, Castor fiber) have been rapidly introduced in many western European countries and landowners and scientists are learning how to live with the expanding population. I have helped organize and conduct international meetings over the past few years that have brought together scientists to discuss the issues involved with beaver introductions. I will continue this work (I was a co-organizer for a 2003 Beaver Symposium in the Netherlands), and I am also developing a joint American-European beaver research program. This research will examine the behavior and population biology of the two beaver species where they live close to each other in Finland. The North American beaver was introduced in Europe in the mid-1900s and there is a viable population in Finland. Grant support is currently being solicited to support this research.
I also have a small mammal community ecology project in the Sierra Nevada area of California. This project examines the population dynamics and community structure of small mammals (rodents) in a multiple use forest (the Tahoe National Forest). Little information exists for this region of the Sierra Nevada and basic population data on forest mammals will support forest use planning.
Selected publications include: Population Biology and Behavioral Ecology of Mammals and Behavior and Conservation of Beavers.