Katie Chabriere talks to Roisin Black, Yorkshire Dales ranger at Malham Tarn Field Centre, about the water vole reintroduction project taking place there.
KC: Why have water voles declined so much, and why use Malham Tarn as a reintroduction site?
RB: One of the main problems is that 90% of our waterways, the voles’ habitat, have disappeared or changed dramatically in recent times. But American mink, which escaped for various reasons from fur farms in the 60s, have drastically reduced their numbers. Pretty much everything preys on water voles but the mink, unlike most other predators, are small enough to fit into their burrows, and gorge on them. This is a classic example of a species that should not be in the ecosystem. Once the balance is upset then the food chain is completely disrupted and a species becomes threatened. In urban areas domestic cats are a bit of a problem too due to their hunting habits, but it is more the development for housing and industry and the channelling of streams in urban areas that causes most habitat loss which is the bigger issue. The habitat at Malham Tarn is perfect for reintroduction because there are slow-moving steams, banks and burrows. Also there is evidence that the voles were here before and that they are having an extremely positive impact on the ecosystem now. We also know there have been no mink seen in the area for more than ten years.
KC: What about water quality?
RB: The water quality at Malham Tarn is excellent. In the past there have been issues relating to various discharges and use of chemicals but these have been tackled through working with our neighbors and other organisations so the water quality is now very good. The area is also protected from cattle that can collapse the banks going down to the water. Although there is still a long way to go, water quality in general has improved country-wide, due in part to the Water Framework Directive, implemented by the Environment Agency set out by the European Union.
KC: How did the reintroduction take place?
RB: We used a soft reintroduction method with two phases. Voles were placed in cages within the habitat and monitored, then eventually released. Within one year the voles have had a hugely positive impact on the waterways and brought more wildlife to the area.
KC: How many voles are there now? Can visitors to the tarn view them?
RB: It’s quite difficult to know how many voles there are because there is naturally an 80% decline in populations in the Winter, then in Summer they breed 4 or 5 young every 28 days! Around 200 voles were released initially and this number has not only stabilised but is increasing. We will know the definite figures in a survey to be carried out next year. Visitors to the tarn, if they are quiet and a bit lucky, can catch glimpses of the voles whilst walking around the boardwalk viewing areas. In actual fact we rely in part on visitors reporting sightings in order to estimate numbers. Protection of this area is vital both for the voles and for the peat bogs at the tarn, as these bogs are internationally important wetlands that sustain incredible insect and other wildlife. Releasing the voles here helps get the Tarn on the map and if the public show an interest in the voles then they might get interested in other areas of conservation. This really is an example of sensibly and sensitively carried-out Eco Tourism/education at its best.
KC: What else can nature-curious kids and adults do at the Tarn?
RB: The Field Centre provides activities for schools, universities and colleges based around more formal, educational field trips. The National Trust activities are less curriculum-based and are open to the general public. We offer wild flower walks in Summer months that are often free, and then bat walks and night sky walks to name but a few of the activities.
KC: Many thanks Roisin and good luck bringing back this gorgeous creature to its natural habitat.