Proceedings of the Vertebrate Pest Conference

Management for beaver now ranges from lethal removal of nuisance individuals to reintroduction of individuals for wetland restoration and to increase wildlife and habitat diversity. Management, or lack thereof, is driven largely by stakeholder concerns at the local and regional level. In many cases with management of beaver and other species, there are unclear visions of how wildlife populations may exploit resources after successful restoration or with changing landscape conditions (e.g., habitat quality and competition). With increasing conversion of the modern-day landscape, natural resource managers must make pragmatic decisions on the potential effects habitat alteration has on system stability. In 2000, the United States Army Corps of Engineers received approval from Congress to construct the Tres Rios Ecosystem Restoration and Flood Control Project in Phoenix, Arizona. Upon completion, this multi-phased, 7-mile (11.3-km), 1,500-acre (607-ha) project is designed to include a 4.25-mile (6.8-km) flood protection levee, an effluent pump station, and development/maintenance of emergent wetlands, riparian corridors, and open water marshes to replace existing non-native saltcedar. In 2000, Tres Rios constructed a demonstration area onsite that used reclaimed wastewater from the 91st Avenue Treatment Plant to establish wetland habitat. Simultaneously, we began the Tres Rios Beaver Research Project to determine the possible effects beaver have on riparian and wetland habitats. Studies within this project found that existing non-lethal management techniques were generally ineffective; however, topical application of fructose and polyethylene glycol showed promise as a technique to increase palatability of invasive Tamarisk spp., while palatability of native tree species could be reduced by application of an herbivore repellent. Other studies developed new techniques for anesthetizing beaver and increasing radio transmitter retention time on beaver. Through monitoring movement of beaver and using landscape genetic techniques to explore population diversity, researchers found deviations from published literature on beaver, suggesting that density-dependent factors may be driving beaver behavior and movement in this environment. We describe the planning process involved in developing these research studies to address stakeholder concerns.