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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.

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Presentation on theme: "1 European Beavers (Castor fiber). 2 European Beavers  Often do not construct large dams – ability was largely lost during isolation in European sites."— Presentation transcript:

1 1 European Beavers (Castor fiber)

2 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 3

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 4

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 ! 5

6 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 7 Cotswold Water Park (CWP)  12 kits born in January 2008 (first seen 17 th 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 8

9 The Site 9 7x7km 49km 2

10 10 Interactions with other species

11 11

12 Interactions with other species 12

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 ? 13 N = ?

14 14 Your turn…

15 15

16 Information From Article 16

17 17

18 18 For any EV Fields: use 0 For any info in Table 1, use the ‘Medium’ model

19 19

20 And they have…  Released 3 beaver families 20

21 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 21

22 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... 22


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