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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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