Beavers near Lochgilphead
It’s 400 years since beavers were part of the Scottish scene. Most of them were killed for their thick, strong fur and they became extinct. But in May 2009, a five-year scientific trial run by the Scottish Wildlife Trust and the Royal Zoological Society of Scotland brought these intriguing animals back to Knapdale forest near Lochgilphead. Introducing a new species has to be tried out very carefully in case it proves disastrous in any way, but so far, the Knapdale beavers seem to be doing well and causing no bother.
A report produced by the Argyll Fisheries Trust shows that beavers are having little observable effect on freshwater fish in streams in the trial area. This is because the beavers seem more interested in the lochs, though that may change as their numbers increase. The James Hutton Institute has been monitoring woodland around the edges of the lochs where the beavers live, and reports that 18 months after the beavers were released, about 10% of trees in the survey area were showing signs of beaver activity. Most of this number had been felled, though many trees also showing signs of gnawing. Beavers feed on bark, twigs and leaves, and they also use felled trees and branches for building their lodges and dams, where they store logs and branches underwater for food in the winter. Nearly all the trees affected (72%) were within 10 metres of lochs and streams, and the majority were within 350 metres of beaver lodges.
The trees gnawed or felled were often little more than saplings measuring 5cm in diameter, but some were much bigger. A few measured as much as 30cm, meaning they were quite mature trees, but strangely, most of the trees felled by beaver gnawing have not died. The following spring, they budded up again from the stump – which of course is in the beavers’ own interest. They have a strong preference for willow and will travel quite a distance from the water’s edge to find it. They like rowan as well, but they avoid alder. Birch is the species they most often used, since this is the most commonly found tree in the survey area.
The beavers have built a dam at Dubh Loch that has caused quite a flood. Willow and alder may survive, but the long-term effect may mean the area turns into ‘very wet willow woodland or even wetland.’ Martin Gaywood, who leads the scientific monitoring of the trial for SNH said: ‘Beavers have complex effects on other wildlife, and measuring these changes is essential. This trial will give the Scottish Government the information it needs to decide whether beavers should be reintroduced on a wide-scale in Scotland.’
Maybe we will see beavers on Arran one of these days. Who knows?
