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European Beavers ( Castor fiber ). European Beavers. Often do not construct large dams – ability was largely lost during isolation in European sites Any dams are small, with beavers instead living in bank burrows or stick lodges Once extensive distribution… - PowerPoint PPT Presentation
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European Beavers (Castor fiber)
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European Beavers
Often do not construct large dams – ability was largely lost during isolation in European sites
Any dams are small, with beavers instead living in bank burrows or stick lodges
Once extensive distribution…
…But hunted for fur to the point of extinction in much of Europe, including Britain and Sweden
Re-introduced from Norwegian stocks to Sweden and since 1920s to 13other countries
The Case for Reintroduction A keystone species in creating/maintaining riparian
ecosystems - extirpation from the UK has been a key factor in the historical depletion of this habitat
Ethical obligation to reinstate a ‘missing species’?
Unlikely to pose threats to humans or other wildlife
Eco-tourism – potential direct financial benefits to the areas where beavers are reintroduced
Recent study by Oxford Uni suggested that beavers would bring around £2 million per year to the local economy
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The Case for Reintroduction All beaver reintroductions have occurred without
major problems or conflicts with other land uses and viable populations have been restablished in all cases except:
Netherlands (reintroduction is too recent to evaluate)
Switzerland (numbers are small, though increasing)
Not a one-way street? If unforeseen problems occur, specific habitat requirements and small home territories would make beavers easy to trap – reintroduction is controllable and even reversible
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The Case Against Reintroduction
Native species have become adapted to habitat without beavers
In France, there has been:
A small amount of damage to trees in a conifer plantation
Problems where beavers had blocked a culvert under a road, causing temporary flooding
Possible problems of dams impeding the movements of brown trout in the river (unconfirmed)
COST - £1.8 million for a reintroduction scheme!5
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Cotswold Water Park (CWP) In October 2005, 6 beavers from Bavaria were
released into a secure enclosure at South Cerny (not exactly wild!)
The 20 hectare enclosure contains 2 artificial lodges, a 15ha lake, 3ha of woodland and grassland
Territory disputes led to one family being relocated
The remaining family no longer uses the artificial lodge but has created a natural stick lodge
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Cotswold Water Park (CWP)
12 kits born in January 2008 (first seen 17th July 2008) – the first young born in the UK for 400 years
CWP is studying the impact of beavers on habitat:
Felling of trees has increased nesting sites for breeding water birds
Diversity of marginal vegetation (+ dragonflies) has increased
Information will be used to guide future Beaver re-introduction projects
Scotland May 2008: Scottish Wildlife Trust / Royal
Zoological Society of Scotland granted a licence by the Scottish Government for beaver reintroduction
Six-year trial taking place at Knapdale, Mid-Argyl
Individuals were captured in Norway in Autumn 2008
They were released in May 2009 after six-months in quarantine
This was the first-ever formal wild reintroduction of a native mammal to the UK
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The Site
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7x7km49km2
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Interactions with other species
Interactions with other species
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Interactions with other species
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Scotland One of the first things Scottish Heritage had
to consider was the number of individuals to release
This was a multi-part decision
How many?
Sex ratio?
Ages of individuals ?
Whether to release all at once or supplement ?
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N = ?
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Your turn…
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Information From Article
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For any EV Fields: use 0
For any info in Table 1, use the ‘Medium’ model
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And they have…
Released 3 beaver families
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Families
Three beaver families were released at carefully selected sites:
Family 1 (4 beavers) released into Loch Coille Bharr
Family 2 (4 beavers) released into Loch Linne
Family 3 (3 beavers) released into Creag Mhor Loch
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Problems Shortly after release, a juvenile male from the
family 1 died: post-mortem results inconclusive
One week post release the adult female from family 1 disappeared at the same time as shooting was heard – no sign since this time
Her male partner disappeared, later being tracked to the Crinan Canal, then the Lakeland Marine Farm
Juvenile female from family 1 also disappeared and her signal has not been picked up since...
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