An annotated bibliography of beaver literature Prepared for the Oregon Department of Fish and Wildlife’s Beaver Working Group by Dana Sanchez, Department of Fisheries and Wildlife, Oregon State University Subjects Climate change Conservation of other wildlife species Damage Dams (including construction, location, and as index to population size/density) Disease, including toxicology Dispersal, movements, and home range Ecosystem function Floodplain functions (and ecological relationships) Food habits and diet Genetics Habitat Relationships Human dimensions Hydrology Interspecific interactions and relationships Management Monitoring and survey methods Population dynamics and demographics Relationships with invasive species Relationships with Salmonid species Relocation (translocation) Reproduction Restoration Trapping effects Urban and road crossing impacts Wetland function and restoration Climate change Boudreau, R. E. A., J. M. Galloway, R. T. Patterson, A. Kumar and F. A. Michel. 2005. A paleolimnological record of Holocene climate and environmental change in the Temagami region, northeastern Ontario. Journal of Paleolimnology. 33:445-461. The Arcellacean (Thecamoebian) fauna was assessed in five Holocene sediment cores obtained from James and Granite lakes in the Temagami region of northeastern Ontario. In addition, palynological analysis was carried out on two of these cores, one each from James and Granite lakes. The first indication of postglacial colonization by plants was the appearance of rare Cupressaceae pollen, dated to 10,800 yr BP. Plant diversity began to increase by 10,770 yr BP when Pinus spp. and Larix migrated into the area. The first appearance of arcellaceans occurred after 9650 yr BP in assemblages dominated by Centropyxis constricta and opportunistic December 16, 2008 version Centropyxis aculeata. High abundances of charophytes in the cores until 8800 yr BP indicated that macroalgae were proliferating at this time. This deposition is interpreted to have occurred during the draining of an ice-marginal lake following the retreat of the Laurentide Ice Sheet. Based on pollen analysis, warmer conditions associated with the Holocene Hypsithermal prevailed in the area from 6250 to 4115 yr BP. The stable, open Great Lakes - St. Lawrence type forest that developed here at the beginning of the Hypsithermal continues to prevail to the present. The periodic colonization of the lake by beavers ( Castor canadensis) acted as a control on water- level and eutrophication through the Holocene. Evidence of eutrophication was indicated in the core samples by the abundance of high levels of the alga Pediastrum and the arcellacean Cucurbitella tricuspis. Eutrophication periodically developed when beavers dammed a site, causing the rate of flow in drainage streams to slow and stagnant conditions occurred. When the site became depleted of the nearby trees, which were preferred by beaver ( Betula, Alnus and Populus), the dam would be abandoned, causing the water- level to drop. Stagnant conditions were reduced as flow levels increased, reducing eutrophication and resulting in recovering forest stands. In addition, the lowering water levels would result in encroachment of the forest along the lake shore. This cycle occurred many times in the history of this lake as indicated by fluctuations in the size of arcellacean populations. Hood, G. A. and S. E. Bayley. 2008. Beaver (Castor canadensis) mitigate the effects of climate on the area of open water in boreal wetlands in western Canada. Biological Conservation. 141:556-567. Shallow open water wetlands provide critical habitat for numerous species, yet they have become increasingly vulnerable to drought and warming temperatures and are often reduced in size and depth or disappear during drought. We examined how temperature, precipitation and beaver (Castor canadensis) activity influenced the area of open water in wetlands over a 54-year period in the mixed-wood boreal region of east-central Alberta, Canada. This entire glacial landscape with intermittently connected drainage patterns and shallow wetland lakes with few streams lost all beaver in the 19th century, with beaver returning to the study area in 1954. We assessed the area of open water in wetlands using 12 aerial photo mosaics from 1948 to 2002, which covered wet and dry periods, when beaver were absent on the landscape to a time when they had become well established. The number of active beaver lodges explained over 80% of the variability in the area of open water during that period. Temperature, precipitation and climatic variables were much less important than beaver in maintaining open water areas. in addition, during wet and dry years, the presence of beaver was associated with a 9-fold increase in open water area when compared to a period when beaver were absent from those same sites. Thus, beaver have a dramatic influence on the creation and maintenance of wetlands even during extreme drought. Given the important role of beaver in wetland preservation and in light of a drying climate in this region, their removal should be considered a wetland disturbance that should be avoided. (C) 2007 Elsevier Ltd. All rights reserved. Norment, C. J., A. Hall and P. Hendricks. 1999. Important bird and mammal records in the Thelon River Valley, Northwest Territories: range expansions and possible causes. Canadian Field-Naturalist. 113:375-385 | 375. December 16, 2008 version Included in information on the status of 50 bird and five mammal species in the Thelon River Valley, Northwest Territories, Canada are nine northward and three southward breeding range extensions for birds, along with 16 species not previously recorded in the Thelon Wildlife Sanctuary. Several hypotheses may explain northward range expansions, including a recent warming trend at the northern treeline during the 1970s and 1980s. Robinson, S., A. B. Beaudoin, D. G. Froese, J. Doubt and J. J. Clague. 2007. Plant macrofossils associated with an early Holocene beaver dam in interior Alaska. Arctic. 60:430-438. Dynamic climate changes and expansion of new biomes characterize the late Pleistocene-early Holocene of eastern Beringia. Analysis of plant macrofossils from an early Holocene (ca. 9300 14C yrs BP) beaver dam in central Alaska provides insight into the local environment and vegetation. The plant macrofossil assemblage comprises remains of trees and shrubs, graminoids, and forbs, including Betula sp., Carex sp., Rubus sp., Eleocharis sp., Scirpus sp., Potamogeton sp., Najas flexilis and Typha latifolia, indicative of standing water of a beaver pond. Bryophytes from the beaver dam include Warnstorfia spp. and Drepanocladus aduncus, suggesting shallow, stagnant, or slow-moving water. The presence of Najas flexilis, Typha latifolia, and modern beaver (Castor canadensis) suggest that central Alaska had a warmer climate during the early Holocene. Skelly, D. K. and L. K. Freidenburg. 2000. Effects of beaver on the thermal biology of an amphibian. Ecology Letters. 3:483-486. It is often assumed that ecological interactions happen at rapid rates relative to evolutionary change. In this study the authors examined the development and physiology of an amphibian (Rana sylvatica) from populations found in forested wetlands, and from wetlands that had been cleared by reinvading beaver (Castor canadensis). Embryos from beaver wetlands hatched at lower rates when raised in a shaded, common garden setting compared with embryos from forested wetlands. Larvae from beaver wetlands had higher critical thermal maxima compared with conspecifics from forested wetlands. These patterns suggest that R. sylvatica populations may have diverged rapidly (in less than 36 years) in response to changes in their environment induced by another species. Other agents of thermal change, such as anthropogenic landscape conversion or alteration of global climate, could have analogous impacts on wetland dependent species such as amphibians. Telfer, E. S. 2004. Continuing environmental change - An example from Nova Scotia. Canadian Field-Naturalist. 118:39-44. Information from personal experience, from community elders and published literature served as a basis for evaluating environmental changes in the District of North Queens and adjacent areas of Southwestern Nova Scotia over the past century. Major events included disappearance of the Caribou (Rangifer tarandus), the arrival of White-tailed Deer (Odocoileus virginianus), the severe reduction of Canada Yew (Taxus canadensis), disappearance of Lynx (Lynx canadensis), a major dieoff of Striped Skunks (Mephitis mephitis), decline of American Beech (Fagus grandifolia), the loss of mature birch (Betula spp.), the severe reduction of Moose (Alces alces), the arrival of the American Dog Tick (Dermacentor variabilis) and Coyotes (Canis latrans), and December 16, 2008 version the restoration of Beaver (Castor canadensis). The proximate cause of many of those changes were plant and animal disease, while the ultimate causes were naturally occurring animal range expansion and human impacts. The warming of the climate over the past 150 years probably played a role. The nature and timing of the events could not have been predicted. Wolf, E. C., D. J. Cooper and N. T. Hobbs. 2007. Hydrologic regime and herbivory stabilize an alternative state in Yellowstone National Park. Ecological Applications. 17:1572-1587 | 1572-87. The article focuses in determining the relative influence of hydrologic regimes, as controlled by climate variation, beaver damming, and