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An Overview of the International Beaver Ecology and Management Workshop Wildlife Concerns Updates An Overview of the International Beaver Ecology and Management Workshop JIMMY D. TAYLOR 11,USDA, APfIIS, Wildlife Services, National Wildlife Research Center, Olympia Field Station, Olympia, WA, USA DAVID L. BERGMAN, USDA, APHIS, Wildlife Services, Phoenix, AZ, USA DALE L. NOLTE, USDA, APHIS, Wildlife Services, Fort Collins, CO, USA ABSTRACT On 9- 12 October 2007, the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services (WS) hosted the International Beaver Ecology and Management Workshop in Chandler, Arizona. The workshop was jointly sponsored by the Multi-City Sub-Regional Operations Group (SROG), Tres Rios Ecosystem Restoration and Flood Control Project and WS. The SROG management is comprised of representatives from the cities of Phoenix , Mesa , Glendale, Scottsdale, and Tempe. The workshop emphasized the management of beaver , their ecology, the part they play as a keystone species, and the issues they cause as an invasive species outside of the United States. The workshop began with a keynote address by Dr. Dale Amer on "Historical, economical, and ecological aspects of beaver restoration and management. " The keynote address was followed by a session on beaver ecology throughout North America. The workshop participants were updated by several papers on "Developing Research Tools" wherein the latest advances in technology were presented . The 2nd day of the workshop began with a 2nd keynote address by Dr. Dietland Millier-Schwarze , "Knowing beaver behavior as a basis for good management." In North America, the perceived values of beaver range from negative (causing extensive damage) to positive (ecosystem engineer that promotes biological diversity) ; while attitudes towards beaver in South America may be more strongly negative as beave r are an invasive species that destroys native biodiversity. To address beaver damage, several pap ers add resse d the use of individual beaver manage ment techniques , cooperative programs , and changing beaver behavior. The workshop ended with the challenges and successes in developing population genetic models for beavers. Beaver management continues to be a worldwide affair with a number of success stories and a number of questions remaining to be answered. The workshop was well attended with 75 registrants representing 5 countries and 16 states. KEY WORDS beaver , biological diversity , Canada, Castor canadens is, ecosystem engineer , management , North America, nuisance , South America significance m North America, North American beaver (Castor comparatively little scientific research has canadensis), hereafter beaver(s) , are been published on beaver compared to other, ingrained in Native American culture in perhaps more charismatic species. For North America along with the wolf (Canis example, in a simple search using scientific lupus), bison (Bison bison), and bald eagle names in Scopus, July 2009, we found 426 (Haliaeetus leucocephalus) . They also are a articles contammg "Castor canadensis" significant part of the culture of European compared to 3,300 articles for "Cervus settlers in North American as their images elaphus"; 2,147 for "Odocoileus are found on coins, flags, and historical virginianus"; and 1,637 for "Canis lupus". roadside markers. The quest for beaver pelts Additionally, we found only one book almost extirpated the species from North (Millier-Schwarze and Sun 2003) and one America in the 19th century; however, the published proceedings (Busher and conservation efforts of the 20th century that Dzi~ciolowski 1999) summarizing beaver led to their recovery provide one of the research . greatest success stories in modem wildlife Throughout North America , management. Despite their histo1ical management for beaver ranges from Proceedings of the 13th WDM Conference (2009) 225 J. R. Boulanger , editor reintroduction of individuals for wetland organizations; and academia from 5 restoration to lethal removal of individuals countries and 16 states. causing damage . Introduced North In this paper, we summarize the key American beaver in Europe, along with their points of the presentations delivered at the congener European beaver (Castor fiber), workshop. Where research presented at the are managed similarly. Introduced beaver in workshop has since been published, we refer South America are considered unwanted, to cited results accordingly. However, in the exotic species that are destroying native absence of published work , we have diversity at an alarming rate. Where beaver refrained from listing specific data of others cause damage at the human-wildlife presented at the workshop. Thus, our interface, they are often referred to as discussion of their presentations is limited to nuisance beaver. Where their damming the general context of their abstracts. efforts are desirable, they are referred to as Presentations were given in the following ecosystem engineers. Because of the sessions: beaver ecology; developing competing values associated with beaver research tools; beaver biology and behavior; and the large number of laws, regulations , beaver as an invasive species; management; and opinions guiding their management or and genetics. lack thereof, we felt it necessary to bring natural resource managers and policy BEA VER ECOLOGY makers together to discuss current and future Beaver are often referred to as wetland beaver research and management topics . engineers because of their ability to create On 9- 12 October 2007, the U.S. and maintain standing water through dam Department of Agriculture, Animal and building. They also are described as a Plant Health Inspection Service, Wildlife keystone species because of their significant Services (WS) hosted the International impact on ecosystem structure and function . Beaver Ecology and Management Workshop The wetlands created by beaver are well in Chandler, Arizona to exchange documented as habitat for other vertebrates. knowledge of current beaver management One speaker described the positive and research and to highlight work ecological value that beaver ponds have on conducted on Ires Rios Ecosystem bird diversity in the southeastern United Restoration and Flood Control Project (see States . In a study conducted on 5 paired sites Taylor et al. 2008). The workshop was in Mississippi, she reported that beaver jointly sponsored by the Multi-City Sub­ wetlands supported more birds with Regional Operations Group (SROG) , Ires declining populations and higher Partners in Rios Ecosystem Restoration and Flood Flight conservation concern scores, and that Control Project , and WS. SROG their cumulative conservation value was 4- management is comprised of representatives fold higher than that of birds in adjacent from the cities of Phoenix , Mesa, Glendale , upland habitat. Another speaker described Scottsdale, and Tempe. The workshop was how beaver wetlands in the southeastern well attended with 75 registrants. Thirty­ United States provide quality nesting, brood­ four presentations were delivered including rearing, foraging, resting, and roosting keynote addresses by 2 well-known beaver habitat for dabbling and perching ducks. He researchers: Dr. Dale Arner and Dr. Dietland went on the describe how proper Miiller-Schwarze . Presenters and audience management of these wetlands through members represented local, state, federal, water control, planting, and selective tree and provincial governments; non-profit harvesting can further improve habitat Proceedings of the 13th WDM Conference (2009) 226 J. R. Boulanger, editor conditions for waterfowl throughout their fisheries and wildlife delivered presentations annual cycle. within the ecology section. The first spoke While reports of avian use of wetlands of the plans to increase public awareness , are found readily among published beaver provide leadership and strategic direction, literature, fewer studies have examined the and secure funding to increase the beneficial influence of habitat modification by beaver effects of beaver in appropriate areas within on herpetofauna. One presenter reported the state. The second speaker presented the significant reptile and amphibian use of results of a model used to delineate beaver permanent (i.e., swamps) and ephemeral habitat based on aquatic habitat inventory (i.e., pools) wetlands created by beaver in data. His preliminary results indicated that the Interior Flatwoods Physiographic Region some metrics captured in the inventory can of Mississippi . She submitted that be useful in predicting beaver presence . identification and protection of these areas Furthern1ore, he recorded that beaver in this may be necessary to promote diversity of region can be grouped as 1) those that build herpetofauna on public lands in this region . dams in smaller streams and 2) those that Beaver wetlands also promote habitat for occupy larger streams, forgo dam other mammals . In the southeastern United construction , and live in bank dens. He States, beaver flooding and gnawing activity submitted that future research , restoration promote cavity formation in trees such as attempts , and development of management baldcypress (Taxodium distichum), plans should recognize the impacts of these sweetgum (Liquidambar styraciflua) , and behavioral differences . black tupelo (Nyssa sylvatica), which Beaver population growth is influenced provide maternal and overwinter roost sites by many factors . One presenter reported the for at least 6 species of bats. These wetlands results of a 6-year study
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