The beaver (Castor sp.) is an ecosystem engineer of wetland habitats. Its actions modify both aquatic and terrestrial areas, and several species (e.g. waders, ducks, frogs) are aided by these changes. Beavers are therefore keystone species, and not only do they increase biodiversity through their actions, but can also positively influence humans e.g. mitigating the effects of flooding and drought and by improving water quality. In fact, beavers have such strong effects on their habitats, that their absence from an area where they would naturally occur can actually mean that the area is in a non-natural state and its ecosystem functioning may be (severely) modified.
© Sari Holopainen
This may well be the case in Britain, where Eurasian beavers (Castor fiber) were hunted to extinction 400 years ago. Some hope maybe on the way though; last week saw the publication of a final report by the Scottish Wildlife Trust and Royal Zoological Society of Scotland, following a licensed release of beavers into Argyll, Scotland. The program, nicknamed the Scottish Beaver Trial (SBT), has looked into the biological, social, and economic effects this release has and will have on Scotland, and results seem promising.
Four beaver families (a total of 17 individuals) were reintroduced to Argyll in 2009, following a long round of discussions and debates that began in the 1990s. Opposers of the Trial voiced concerns of the possible negative impacts the species may cause, e.g. by flooding land and killing trees. The first license application was rejected, and only after the second application did the Scottish Government grant the SBT the right to execute a trial release, in fact the first reintroduction of a mammalian species in the UK to ever take place. The four beaver families were brought into the country in 2008, and after a six-month quarantine period were released into three separate Argyll lakes. The release area is mainly owned by the Forestry Commission Scotland (FCS), and it is also a working forest. This means that the beavers’ actions and impacts on forestry and forest management areas could be monitored. For this same reason the area already had an extensive road and path network that could be effectively utilized in beaver eco-tourism, an aspect that significantly helped to promote the program to the public and local residents. Parts of the area were already designated Special Areas of Conservation (SAC) or Special Protection Areas (SPA) because of their native flora and fauna, and thus visitor facilities were available. Viewing platforms and floating pontoon walkways were constructed to maximize ease of access.
The source population was chosen from Norway, as Scandinavian beavers were concluded to morphologically most closely resemble their UK cousins, based on samples taken from fossil beaver skulls found in Britain. The IUCN has set a strict protocol for species reintroductions and translocations, necessitating the use of the taxonomically closest population as the source.
After release the beavers were monitored by staff using e.g. radio-tracking, visual sightings, and annual health checks, and most individuals seemed to quickly adapt to their new surroundings. Post-release the separate families have accomplished some impressive feats: in total they have created 13 000 m2 of new freshwater habitat (the equivalent of 10 Olympic swimming pools), and constructed several dams (the largest being 25 m in length) and lodges (the largest nearly the same size of a double garage, 7.7×2.1×11.3 m). Despite the radio-tracking, several released beavers and their wild-born offspring disappeared. Five were later found dead, one was caught outside the relocation area and brought back, but a few were never found and were presumed to have moved outside the FCS area.
The first successful reproduction was recorder in the spring of 2010, with a single kit born to two separate beaver families, and breeding occurred during each year of the SBT.
The Trial included monitoring programs for several species, groups, and habitats, to assess how the beavers influenced their populations and ecology, e.g. woodland vegetation and river habitat assessments, mammal (mink and otter), aquatic macrophyte, and dragonfly and damselfly surveys. The socio-economic effects of the SBT were also assessed. The first visual sign of beaver presence was tree-felling, followed by the building of canals, burrows, lodges, and dams. Dam building was closely monitored, so as to ensure that water levels in the SAC areas did not rise to detrimental levels for organisms protected in the areas. When such situations occurred, the dams were either removed or a device was installed to manage the water flow.
The Trial has been a huge endeavor, resulting in the publication of 24 independent journal articles and conference proceedings, and engaging 23 colleges and universities in addition to the three organizations in charge of the program. Volunteering has been enabled from the onset, and has also produced valuable information concerning the beavers’ actions and movement. An estimated nearly three million people were somehow engaged during the trial, ranging from school visits, education programs, guided walks to BBC’s Springwatch that aired several episodes on the Trial. Residents of the relocation area were involved in program planning well ahead of its onset, and planning was made as transparent as possible. The public (including residents) were again consulted at the end of the trial period. The trial also worked with local businesses to develop a ‘beaver brand’ to encourage nature-based tourism in the area. Over the course of the program, the trial won several awards for enhancing local tourism.
The active engagement of both local residents and entrepreneurs and the general Scottish public led to very positive attitudes towards the relocation and the possible future of beavers in Scotland. An estimated 74% of adult Scots favor beaver reintroductions, and 84% of local residents support wild beavers in their area. Such levels can be considered a major success, as the Trial did after all bring in a species that the British have never seen on their home turf, and additionally a species that causes a lot of changes in its living environment, some of which can be potentially problematic and destructive. The SBT succeeded in dispelling fears of the beaver causing socio-economic and/or ecological problems, and showed that local communities can in fact benefit from their reintroduction.
The Trial serves as an excellent example of how relocations should be handled so as to ensure success. Now it is up to the Scottish Government to decide on the beaver’s future in Britain – hopefully a bright one at that. Until a decision is made, the beavers will remain in Argyll. With luck the population will be aloud to stay and more reintroductions elsewhere in the country are on the way.
For more info, visit http://www.scottishbeavers.org.uk