Beaver habitat

The saturation density in northeastern hardwood forests is estimated to be approximately 1 col/km (Nordstrom, 1972). Most colonies in our study area are located along streams. The vegetation consists of deciduous forest with large species diversity. At many colony sites, all woody vegetation has been cleared by the beaver for as much as 100 m from the pond. Even red pine (Pinus resinosa) and scotch pine (P. sylvestris) plantations are utilized in winter although they usually are not considered beaver habitat. 

Mammalian wildlife from uncontaminated habitats usually contain less than 0.1 to about 5 mg Ni/kg DW in tissues in nickel-contaminated areas, these same species have 0.5 to about 10 mg Ni/kg DW in tissues (Outridge and Scheuhammer 1993 Chau and Kulikovsky-Cordeiro 1995), with a maximum of 37 mg/kg DW in kidneys of the common shrew (Sorex araneus) (Table 6.6). Nickel accumulations in wildlife vary greatly between species. For example, tissues of mice have higher concentrations of nickel than rats and other rodents, while beavers and minks have higher nickel concentrations in their livers than birds in similar sites near Sudbury (Chau and Kulikovsky-Cordeiro 1995). 

Welsh, R. G. and Miiller-Schwarze, D. (1989). Experimental habitat scenting inhibits colonization by beaver, Castor canadensis. Journal of ChemicalEcology 15,887-893. 

Ecological key(stone) species are species that play a major role in ecosystem performance, productivity, stability, and resilience. These species may also play an important role in ecosystem function (see below) and include 1) species that are critical determinants in trophic cascades, such as piscivorous fish and large herbivores and 2) species that are ecological engineers, that is, those that have a large influence on the physical properties of habitats such as rooted submerged macrophytes and beavers... 

Did the beavers invest much in the infrastructure Is it a site with a good food supply in terms of plant species and abundance Does this beaver site create habitat for other plant and animal species Are any rare or endangered plants or animals present Include any management recommendations. 

Discuss the function of scent marking in the context of the beavers extensive investment in habitat modification. 

The American mink (Mustela vison) occurs throughout most of North America, except for parts of the arid southwest. This species lives in the vicinity of a wide range of aquatic habitats. Mink make their dens in hollows in fallen logs and under stumps, and in burrows taken over from a muskrat or beaver. 

Beavers occupying a watery habitat have nephrons with short loops, while those of the desert rat have long loops. 

Boyce, M. S., 1981, Habitat ecology of an unexploited population of beavers in interior Alaska, "Proceedings Worldwide Furbearer Conf.,"... 

Collins, T. C., 1976, Population Characteristics and Habitat Relationships of Beavers, Castor canadensis, in Northwest Wyoming, Ph.D. Thesis,... 

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