Species as
Ecosystem Engineers
THE BEAVER
Adrian Lloyd JonesNorth Wales Wildlife Trust
The Welsh Beaver Assessment Initiative
• Wildlife Trusts Wales is the lead organisation.
• Management team includes representatives from WTW, CCW, EAW, FCW, Wild Europe and key individuals.
• Primary aim is to investigate the potential for a beaver reintroduction to Wales
Probable distribution of European beaver in
Europe (outwith Russia) after the last Ice Age
(Halley, D & Rosell, F. - 2002)
Beaver distribution by late 19th Century
1. Telemark, Norway. c.1002. Elbe, Germany. <2003. Rhône, France. c. 304. Pripet Marshes, Belarus. <400
Approx population: 1,200 animals
• Pelt (very dense and warm, also for waterproof hats)• Meat (especially during lent)• Castoreum (general remedy)
Landscape change generally unimportant
Present day distribution
Why reintroduce the beaver?
• Legal: Article 22 of the EC ‘Habitats Directive’.• Biodiversity: a ‘keystone species’ in the ecology of
riparian woodlands and wetlands.• Environmental benefits: water quality & quantity.
Socio-economic benefits: public interest, wildlife tourism.
• Moral argument: a species lost through human actions.
Beavers manage wetland ecosystems by...
• Feeding activity – grazing, coppicing trees
• Building activity – dams/ponds, lodges
• Digging activity – burrows, channels
Feeding
Fallen and standing deadwood
Building
Dams
• Aim to achieve a depth of 0.7 – 1.0 metre• Keeps entrance submerged• Enables diving (for predator evasion)• Deeper water enables movement under ice• Easier transport of food and building materials
Easier access to food sources
1964 1967 1992 1994 2002
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Beaver dam 1995
Beavers increase number of fish species
Building and Digging - Burrows and Lodges
Beaver Canals
Beavers in a human influenced landscape
BEAVER PROBLEMS
Feeding on crops• Real damage mostly
minor
Felling trees• No real habitat damage
BEAVER PROBLEMS
Damming• Flooding of man used
areas• Blocking water courses
Digging• Burrows under fields• Burrows in dams and dikes
• Electrical fences
• Protection for trees
• Removing dams
• Protecting culverts
• Trapping problem beavers
• Public relations
Many solutions to problems
Beaver trap baited with apples
Where do problems occur ?• 98% of all problems are within 20m from the water's edge
(95% of all beaver activity within 10m)
Llanbwchwyn SSSI. 67 acres
Radnorshire Wildlife Trust
Biodiverse Beaver Landscapes
Thank you
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