There has recently been an incident in North East Glasgow where a pest control company was called in to deal with what were thought to be rats living at an industrial estate. The animals were in fact grassland water voles and luckily this was flagged up to the pest control company by ecologists a couple of days after poison bait was put down, so the bait was quickly removed. As water voles are afforded legal protection (which is currently a slightly different level of protection in Scotland compared to England and Wales) we want to highlight the presence of grassland water voles that have been recorded living in North East Glasgow and the surrounding area.
Water voles usually live in aquatic habitat, but in 2008 Glasgow City Council Pest Control Officers, responding to a suspected rat infestation, discovered water voles at a housing estate in the east end of Glasgow. Since then water voles have been found extensively throughout the North East of Glasgow, notably in areas of long grass which are not associated with water. These grassland habitats can include parks, gardens, vacant and derelict land and road verges.
Research by the University of Glasgow and other studies have shown these populations to be of national significance in terms of their unusual behaviour and high population densities. The distribution of grassland-dwelling water voles appears to be concentrated in the east of the city, but aquatic water voles are known to occur across Glasgow. It should also be noted that, while some water voles may still be associated with water courses, their burrows may be quite a distance away from the banks (i.e. some burrows have been found 50m away).
Guide to identification of Grassland Water Voles
Water voles are one of Britain’s fastest declining mammals. Because they are a species of conservation concern they are afforded legal protection through the Wildlife & Countryside Act 1981 (as amended) – their burrows/places of shelter are protected from damage, destruction and obstruction and water voles are protected from disturbance while they are using their burrows/places of shelter. However, it should be noted that full protection to cover the animal has been proposed, so the law in Scotland may soon be updated.
Water voles can easily be confused with brown rats, due to their similar size, and there is a risk the methods used to control rats may lead to the accidental destruction of water vole colonies.
For rodent control measures that are put in place in and around North East Glasgow, methods that avoid the unnecessary destruction of water voles or their colonies need to be used*. These include:
Check the Trigger Map to see the area that grassland water voles have so far been found in and are likely to be found in.
Checking for water voles before controlling rats in the area (this should always apply along rivers, burns (ditches/brooks), lochs (lakes) or ponds!). Grassland water vole populations are adaptable and have been known to burrow under decking, use garden ponds and have even been found under portable cabins. Field signs include burrows and soil mounds – soil mounds may be confused for molehills and these may occur in clusters with a single burrow entrance. Field signs are seasonal and vary depending on the time of year.
Find out more about field signs identification for grassland water voles : If identification is in doubt, seek advice of a professional ecologist before taking further action.
Live-capture cage traps are the only safe option – check three times a day to release animals that you do not intend to catch. Avoid the use of break-back/snap traps.
Avoid the use of poison baits to control rats where water voles are known to occur. Do not place poison in burrows – it is illegal to block or obstruct water vole burrows. Where no alternative is feasible, poison should be covered or enclosed in a bait box. Avoid the use of poisoned grain or pellets and use wax or soap blocks instead. If possible site bait off the ground, as rats are more likely to climb than water voles. Poison bait is also best placed around buildings or litter bins where rats are more likely to be attracted to it.
Regularly inspect and monitor the control site, clearing away poisoned corpses. If any dead water voles are found, review the control methods in use. Report any water vole sites you come across to Glasgow City Council Natural Environment Officers firstname.lastname@example.org or Glasgow Museum Biological Records Centre email@example.com.
(*adapted from the Water Vole Conservation Handbook, Strachan et al., 3rd Edition)
More information on Glasgow’s water voles
This note has been produced by the Glasgow Water Vole Project: