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Assessment of the newly reintroduced beavers (Castor fiber) in Denmark and their habitat demands

Vilstrup, Annika (2014) BIOM24 20132
Degree Projects in Biology
Abstract
Popular science summary:

Beavers are back in Denmark

The beaver Castor fiber is an animal which used to be common in most places all over Europe. The beaver has also been an important resource for humans, where especially the meat, the thick fur and the castoreum, a secretion that was used by humans in perfume, medicines and food, was wanted. Therefore, hunting by humans has been the main reason for the beaver population declining to near extinction in the last century. In the beginning of the twentieth century, it was estimated that there were only 1200 beavers left in Europe and Asia. Therefore hunting was banned and reintroductions of the beaver started. At first, the main purpose of reintroduction was hunting, but from the 1970's... (More)
Popular science summary:

Beavers are back in Denmark

The beaver Castor fiber is an animal which used to be common in most places all over Europe. The beaver has also been an important resource for humans, where especially the meat, the thick fur and the castoreum, a secretion that was used by humans in perfume, medicines and food, was wanted. Therefore, hunting by humans has been the main reason for the beaver population declining to near extinction in the last century. In the beginning of the twentieth century, it was estimated that there were only 1200 beavers left in Europe and Asia. Therefore hunting was banned and reintroductions of the beaver started. At first, the main purpose of reintroduction was hunting, but from the 1970's and on, the purpose shifted to be of more ecological reasons. Beavers are ecosystem engineers making various constructions and changes in the landscape and many of these changes have a positive impact on the ecosystem and biodiversity. In Denmark the reintroductions were executed in 1999 in Klosterheden State Forest in Western Jutland and in 2009 in Arresø catchment area in Northern Zealand. In these two areas I did my fieldwork. In total I visited 40 beaver lodges, 27 active and 13 abandoned, where I measured the water depth, velocity, stream width, slope of bank, density of ground vegetation and density of trees used by beavers. These variables were tested statistically to find if they had an impact on whether the lodges where active or abandoned. I also tested if there were statistical differences in these variables between Jutland and Zealand.

Results

I found that the depth of the water by the lodges were deeper by the active lodges, which indicates that the deeper water is important for the beavers. One reason is because the entrance to the beaver lodges has to be underwater to be safe from enemies. I also found some differences in the vegetation between Jutland and Zealand. However, it is more likely caused by the difference in soil type than because beavers have been in Jutland 10 years longer than on Zealand. My results with the depth can be useful in the management of the beavers, which is likely to be more intensified when the populations increase in the future.

Supervisor: Ola Olsson
Master´s Degree Project 30 credits in Conservation Biology
Department of Biology, Lund University (Less)
Abstract
Abstract

The beaver (Castor fiber) was near extinction hundred years ago, and since then reintroductions were executed all over Europe. In 1999, the first reintroduction in Denmark was initiated by the Danish Nature Agency in the hope of creating a diverse landscape and increasing biodiversity. In this study, I wanted to investigate the demands that beavers have to their habitat. Therefore, I assessed physical and vegetative variables at active and abandoned beaver lodges in both Western Jutland and on Northern Zealand. On the basis of my results, I found that the water depth by the lodges had a positive correlation with active lodges, which confirms that deep water is an import habitat demand for beavers.
Please use this url to cite or link to this publication:
author
Vilstrup, Annika
supervisor
organization
course
BIOM24 20132
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
4436247
date added to LUP
2014-05-07 13:39:09
date last changed
2014-05-07 13:39:09
@misc{4436247,
  abstract     = {Abstract

The beaver (Castor fiber) was near extinction hundred years ago, and since then reintroductions were executed all over Europe. In 1999, the first reintroduction in Denmark was initiated by the Danish Nature Agency in the hope of creating a diverse landscape and increasing biodiversity. In this study, I wanted to investigate the demands that beavers have to their habitat. Therefore, I assessed physical and vegetative variables at active and abandoned beaver lodges in both Western Jutland and on Northern Zealand. On the basis of my results, I found that the water depth by the lodges had a positive correlation with active lodges, which confirms that deep water is an import habitat demand for beavers.},
  author       = {Vilstrup, Annika},
  language     = {eng},
  note         = {Student Paper},
  title        = {Assessment of the newly reintroduced beavers (Castor fiber) in Denmark and their habitat demands},
  year         = {2014},
}