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European Beavers ( Castor fiber )

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…

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European Beavers ( Castor fiber )

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  1. European Beavers (Castor fiber)

  2. 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

  3. 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

  4. 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

  5. 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!

  6. 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

  7. 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

  8. 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

  9. The Site 7x7km 49km2

  10. Interactions with other species

  11. Interactions with other species

  12. Interactions with other species

  13. 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 ? N = ?

  14. Your turn…

  15. Information From Article

  16. For any EV Fields: use 0 For any info in Table 1, use the ‘Medium’ model

  17. And they have… • Released 3 beaver families

  18. 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

  19. 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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