[PDF] A Population And Ecological Study Of The Beaver Castor Canadensis Of Yellowstone National Park eBook

Author : Douglas W. Smith
Publisher :
Page : 12 pages
File Size : 39,51 MB
Release : 2012
Category : Aspen
ISBN :

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Despite Yellowstone National Park's (YNP) long history and well studied large mammals and vegetation, beavers (Castor canadensis), an important ecosystem driver, have received relatively little study. We summarize population surveys of beavers that began in 1921 and continued up to the present. The first surveys (1921 and 1923) were from the ground and conducted in a limited area in the northern portion (northern range; NR) of the park. Twenty-five colonies were found and beavers were considered abundant and using aspen (Populus tremuloides) and willow (Salix spp.) as a food source and building material. A follow up survey in 1953 found 6 NR sites, but none of the earlier sites from the 1920s were active and no aspen use was reported. Some locations were reported from the park interior. A limited ground survey was conducted in 1979-80. In 1988-89 and 1994 two incomplete, mostly ground surveys were conducted and estimated 71 and 44 colonies, respectively, in YNP. In 1996, 1998, 1999, 2001, 2003, 2005, 2007 and 2009 complete, park-wide aerial surveys were conducted and active colonies ranged from 44 (1996) to 127 (2007) with an increasing trend. Therefore, in a period of about 90 years (1920s?2000s) the beaver population in the northern portion of the park appears to have declined then increased probably because of a willow recovery.

Author : Douglas W. Smith
Publisher :
Page : 8 pages
File Size : 32,12 MB
Release : 1997
Category : Beavers
ISBN :

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"The number of active beaver (Castor canadensis) colonies in Yellowstone National Park was determined by aerial survey in late October and early November 1996. This was the first near-complete autumn aerial count of beavers in park history. Flying time for the survey was 14.9 house, plus 4 hours ferry time from Bozeman, Montana, for a total of 18.9 hours. Total number of beaver colonies with food caches was 49; three other sites had beaver sign (beaver dam or cutting) indicating that beavers were probably present, but no lodge or food cache was sighted. Ninety percent of the park's beavers were located in three areas: 1) the Yellowstone River southeast of Yellowstone Lake, 2) the Beechler area, and 3) creeks and rivers in the northwest corner of the park which included the Madison and Gallatin rivers, and Cougar, Campanula, and Gneiss creeks. There was only one beaver colony on Yellowstone's Northern Range. All colonies were associated with willow (Salix spp.)."--Page 1.

Author : Matthew Allan Scrafford
Publisher :
Page : 8 pages
File Size : 39,12 MB
Release : 2018
Category : Beavers
ISBN :

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Beavers (Castor canadensis) disappeared from drainages north of Yellowstone National Park in the mid-1900s because of trapping, a potential tularemia outbreak, and willow (Salix spp.) stand degradation by ungulates. Beavers were reintroduced in 1986 after a 40?yr absence with inventories of active-beaver structures completed each fall after reintroduction for 24 consecutive yr. We used this inventory to evaluate the expansion of beaver populations in a riparian environment recovering from past overuse by ungulates. Specifically, we investigated the density of active-beaver colonies and dams, the change in willow cover, and habitats associated with beaver expansion since reintroduction. Successful establishment and expansion of beavers indicate that sufficient resources were available to the population despite the suboptimal condition of riparian vegetation. Carrying capacity on third-order streams was reached approximately 14 yr after reintroduction (2000) with an average annual density of 1.33 (95th percentile = 1.23 ? 1.44 active colonies/stream km) between 2000 and 2010. The average annual density of beaver dams during this time was 2.37 (2.04 ? 2.71 active dams/stream km). Despite the beaver population being at carrying capacity in meadows since 2000, willow cover increased by 16% between 1981 and 2011. We speculate that beaver activities, together with reduced ungulate browsing from predation and habitat loss, combined to increase willow cover. Willow cover and height were positively associated with colony longevity, but numerous other influencing variables included secondary channels, sinuosity, stream depth, and sandbar width. Our results provide evidence that beaver reintroduction can be successful in riparian areas where willow stand condition is less than optimal and that beavers might ultimately improve willow condition. We suggest that reducing ungulate use of overgrazed riparian environments will facilitate the reestablishment of beaver populations. We also provide managers with habitats that should be identified in an environment targeted for reintroduction.

Author : Peter E. Busher
Publisher : Springer Science & Business Media
Page : 184 pages
File Size : 37,65 MB
Release : 2012-12-06
Category : Science
ISBN : 1461547814

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By the end of the 19th century both beaver species had been extirpated from large portions of their native ranges. The global decline in beaver populations was the direct re sult of exploitation by humans. Now, at the end of the 20th century, protection, manage ment, and reintroduction programs, coupled with a decline in the demand for beaver fur and other products, have allowed beaver populations to increase dramatically. Since bea vers actively modify their local environment their activities can conflict with human land use. Because of this, the beaver, once considered a unique and exotic component of wet lands, is now often considered a nuisance species. The history, as well as the current status, of beaver populations in Europe and North America provide insight into how con servation programs work, and into how humans and wildlife interact. The initial plenary lecture of the Euro-American Mammal Congress (July, 1998) was presented by Dr. Michael L. Rosenzweig, a professor at the University of Arizona. Dr. Rosenzweig discussed how humans have used and continue to use natural resources, in cluding wildlife and wildland. He provided evidence indicating that the current model of reservation conservation could not provide a long-term solution to the human-wild life/wildland conflict. Dr. Rosenzweig emphasized that what is required is a move away from purely exploitive activities (I would call this exploitive ecology) and the develop ment of a reconciliation ecology with wildlife.

Author : Stephen David Durrant
Publisher : Good Press
Page : 26 pages
File Size : 15,32 MB
Release : 2019-12-10
Category : Fiction
ISBN :

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"Three New Beavers from Utah" by Stephen David Durrant, Harold S. Crane. Published by Good Press. Good Press publishes a wide range of titles that encompasses every genre. From well-known classics & literary fiction and non-fiction to forgotten−or yet undiscovered gems−of world literature, we issue the books that need to be read. Each Good Press edition has been meticulously edited and formatted to boost readability for all e-readers and devices. Our goal is to produce eBooks that are user-friendly and accessible to everyone in a high-quality digital format.

Author : Dietland Müller-Schwarze
Publisher : Comstock Publishing Associates
Page : 229 pages
File Size : 31,51 MB
Release : 2011-09-01
Category : Nature
ISBN : 0801460867

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Beavers can and do dramatically change the landscape. The beaver is a keystone species—their skills as foresters and engineers create and maintain ponds and wetlands that increase biodiversity, purify water, and prevent large-scale flooding. Biologists have long studied their daily and seasonal routines, family structures, and dispersal patterns. As human development encroaches into formerly wild areas, property owners and government authorities need new, nonlethal strategies for dealing with so-called nuisance beavers. At the same time, the complex behavior of beavers intrigues visitors at parks and other wildlife viewing sites because it is relatively easy to observe. In an up-to-date, exhaustively illustrated, and comprehensive book on beaver biology and management, Dietland Müller-Schwarze gathers a wealth of scientific knowledge about both the North American and Eurasian beaver species. The Beaver is designed to satisfy the curiosity and answer the questions of anyone with an interest in these animals, from students who enjoy watching beaver ponds at nature centers to homeowners who hope to protect their landscaping. Photographs taken by the authors document every aspect of beaver behavior and biology, the variety of their constructions, and the habitats that depend on their presence. Beaver facts: •Just as individual beavers shape their immediate surroundings, so did the distribution of beavers across North America influence the paths of English and French explorers and traders. As a result of the fur trade, beavers were wiped out across large areas of the United States. Reintroduction efforts led to the widespread establishment of these resilient animals, and now they are found throughout North America, Europe, and parts of the southern hemisphere. •Beaver meadows provided early settlers with level, fertile pastures and hayfields. •Based on the fossil record, the smallest extinct beaver species were the size of a muskrat, and the largest may have reached the size of a black bear (five to six times as large as today's North American beavers). Beaver-gnawed wood has been found alongside the skeleton of a mastodon. •Some beavers remain in the home lodge for an extra year to assist their parents in raising younger siblings. They feed, groom, and guard the newborn kits. •In 1600, beaver ponds covered eleven percent of the upper Mississippi and Missouri Rivers' watershed above Thebes, Illinois. Restoring only 3 percent of the original wetlands might suffice to prevent catastrophic floods such as those in the early 1990s.

Author : R Haines-Young
Publisher : CRC Press
Page : 329 pages
File Size : 30,85 MB
Release : 2003-09-02
Category : Nature
ISBN : 0203393031

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The landscape we see and live in is an important part or our everyday lives, be they urban or rural. Environmental concern has grown in recent years, as a result of public awareness of the detrimental impact industry, transport and tourism can have on the ecosystem. This book examines the role of the new technologies of geographical information systems and remote sensing as media for the study of landscape, as they provide tools of unprecedented power which collect, store, manipulate and analyze data so as to support and assist the decisions which the environmental scientist, ecologist, zoologist and botanist make.; "Landscape Ecology and Geographical Information Systems" is international in scope, provides an overview of operational applications, and offers experiences in the form of case studies of applications to vegetation, animals, and hydrology. The book is organized into four sections. It - provides an overview of the uses of GIS and RSS in landscape ecology; debates conceptual issues such applications throw up; considers analytical techniques and technical issues; and offers experiences in the form of Case Studies On Plant, Abiotic And Animal Landscape Ecology.