Wildfowl and Wetlands Trust - Arundel

In September 1999 34 water voles were released into the grounds of the Wildfowl and Wetlands Trusts reserve at Arundel. This was the first ever attempt to reintroduce the species using captive bred individuals into a landscape where it was believed to be extinct. Subsequent surveys revealed a few animals in a recapture programme in 2002 and sporadic sightings of single individuals were recorded in 2004. No field signs of this species were found on site during a series of surveys in 2005 and it was presumed that this population had either become extinct or was so numerically low as to be considered unviable in the medium term. A remarkable aspect of this early attempt was that it succeeded in establishing a small population which survived. The release timing was very late for effective breeding in the year of release as it was believed that water voles commonly cease breeding in mid to late September. Although the project was supported by a further smaller release in the spring of 2002 the numbers involved were small and were drawn almost entirely from a relatively small pool of genetic founders. Genetic interchange is now known to be a critical feature in the successful survival of water vole meta- populations. As soon as isolation occurs even substantial populations are highly vulnerable to a reduction in fecundity. This factor coupled with an absence of immigrating offspring can result in eventual extinction. A significant flood event in 2001 further compromised the prospects of this population and as a result the concept of attempting to

introduce a numerically significant, genetically diverse population at an appropriate seasonal timing was felt to be worth while. On the 16th of August 2005, 82 male and 89 female water voles (Arvicola terrestris ) bred from 7 mixed founder bloodlines at the breeding facility of the Derek Gow Consultancy Ltd near Lifton in Devon were released into the grounds of the Wildfowl and Wetlands Trust's Arundel Centre. A significant number were released into the newly created 'Wetlands Discovery Area' where they rapidly became used to visitors on boats and proved to be a highly visible and popular feature of the experience. The population was resurveyed from the 7th - 11th of November using live catch traps in order to assess individual weight gain, breeding status and juvenile abundance. A further follow up survey was undertaken in March 2006. Field signs by this time were well distributed throughout the site and the capture of a 75g juvenile confirmed that there had been breeding. Water voles are now well established throughout the grounds of the site. Free living populations have formed from migrants outwith the fence and at least one of these is now believed to be self sustaining. Links - click on the logo below