[PDF] Review Of Literature On Mountain Beaver With Bibliography eBook

Author : Alfred J. Godin
Publisher :
Page : 64 pages
File Size : 15,89 MB
Release : 1964
Category : Aplodontia
ISBN :

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This report summarizes the available knowledge about the mountain beaver, Aplodontia rufa, and lists some 260 literature references. Since the first account in 1805, from the Lewis and Clark expedition, a considerable literature has accumulated, much of which is no longer generally available. The mountain beaver, considered the most primitive of living rodents, is found only on the Pacific coast of North America. Type localities and ranges of the seven races are listed.

Author : Bill Pertl Lovejoy
Publisher :
Page : 210 pages
File Size : 45,30 MB
Release : 1972
Category : Beavers
ISBN :

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This report summarizes the results of a field study of a population of the Pacific mountain beaver, Aplodontia rufa pacifica, from August 1965 through August 1967. The study site consisted of a 13. 5- acre grid on a logged over area in the Coast Range Mountains of Benton County, Oregon. The report also includes new data on the postnatal development, growth, and behavior of two litters of mountain beavers born and raised in captivity. The field study involved the mark-release-and-recapture method using a rotational system of live-trapping on a weekly basis. A total of 5, 144 trap-nights yielded 872 captures of 181 individuals. Of this total, 109 were adult animals and 72 were juveniles Males outnumbered females 61.9 percent to 38. 2 percent. Population estimates were determined by direct enumeration and, ranged from a low of 41 in mid-winter to a high of 54 in July. Densities varied from 2.60 to 3.43 animals per acre. Transients made up a considerable portion of the catch. Longevity records of 5 to 6 years were estimated for wild mountain beavers. Adult males had an average home range size of 0.80 acres, adult females 0.42 acres. The home range of juveniles averaged 0.31 acres. Males made longer forays during the summer months when activity was also at a peak. Overlapping of home ranges was common. Male Aplodontia were in breeding condition throughout January, February, and March. Estrus females were available by about mid- February. Lactating females were observed from 8 April through 27 May. Young Aplodontia are weaned at 6-8 weeks of age and emerge from their burrows the following 2 weeks. The earliest date of capture of a young in the field was 3 June. The growth curve of the young was characterized by a rapid increase during the first 8 weeks, followed by a gradual decline, and eventually reached a plateau in 4 months at 69 percent of the adult weight. Animals were classed as juveniles, yearlings, or adults based on their body weights, character of pelage, and breeding condition. Aging of mountain beavers on the basis of weight alone was considered impossible due to the wide range of size within each age class. The average yearling weighed about 710 g, or 88 percent of the adult mean weight of 806 g. Adult males were consistently heavier than females. The largest male weighed 1130 g; the largest female weighed 1070 g. The body weights of adult Aplodontia were at a seasonal low during their reproductive period in the spring and at a high in mid-summer when food was most abundant. Attempts to breed Aplodontia in captivity were unsuccessful due primarily to the hostile behavior of the females.

Author : Ellen Wohl
Publisher : Oxford University Press, USA
Page : 209 pages
File Size : 29,26 MB
Release : 2019
Category : Nature
ISBN : 0190943521

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The ability of beavers to create an abundant habitat for a diverse array of plants and animals has been analyzed time and again. The disappearance of beavers across the northern hemisphere, and what this effects, has yet to be comprehensively studied. Saving the Dammed analyzes the beneficial role of beavers and their dams in the ecosystem of a river, focusing on one beaver meadow in Colorado. In her latest book, Ellen Wohl contextualizes North St. Vrain Creek by discussing the implications of the loss of beavers across much larger areas. Saving the Dammed raises awareness of rivers as ecosystems and the role beavers play in sustaining the ecosystem surrounding rivers by exploring the macrocosm of global river alteration, wetland loss, and the reduction in ecosystem services. The resulting reduction in ecosystem services span things such as flood control, habitat abundance and biodiversity, and nitrate reduction. Allowing readers to follow her as she crawls through seemingly impenetrable spaces with slow and arduous movements, Wohl provides a detailed narrative of beaver meadows. Saving the Dammed takes readers through twelve months at a beaver meadow in Colorado's Rocky Mountain National Park, exploring how beavers change river valleys and how the decline in beaver populations has altered river ecosystems. As Wohl analyzes and discusses the role beavers play in the ecosystem of a river, readers get to follow her through tight, seemingly impenetrable, crawl spaces as she uncovers the benefit of dams.