During August I had the pleasure of getting along to two rather special days at work with Northumberland Wildlife Trust. The first was in a remarkably midge free Kielder Forest where the final release was made as part of Restoring Ratty. This project has seen more than 2000 water voles released into some of the small burns and ditches around the forest as part of the area’s first reintroduction of this once common creature.
The second day involved something even smaller. This time I travelled to Druridge Bay where I participated in the second of two releases of harvest mice on East Chevington Nature Reserve. This time it wasn’t a reintroduction as such but what is technically termed an augmentation. In the early 2000s harvest mice were released on site but they are rather tricky to check up on being so tiny. Like harvest mice in a reedbed could easily substitute for the idiom, like a needle in a haystack. Anyway last year their nests were found but as the original numbers were quite small it was felt that no harm could come from adding a bit of genetic diversity in the form of a couple of hundred more mice.
Why does this all matter? After all who needs more voles, water or not, and more mice? Well, of course, a lot of other creatures need them. Whether we like it or not these small mammals not just deserve to be back in our region but also provide food for things further up the food chain. A healthy ecosystem benefits everything within it from the prey to the predators and the predators’ predators.
Our countryside is sadly missing many key species within it. Some are controversial like Lynx and Beaver but surely smaller things like water voles and harvest mice are less contentious. Before reintroducing things, however, it is vital to ensure that the reasons for their original disappearance are no longer an issue. In the case of water voles years of preparatory work has been put in to ensure that the introduced American mink was not present in the area in sufficient numbers to cause their local extinction again. American Mink in the UK countryside proved to be the death knell of many water vole populations but this wasn’t helped by habitat fragmentation such as through culverting streams and ditches. With few mink and areas where habitat is seen to be largely suitable they have a chance to thrive. From these core areas they have the chance to spread as some water voles will travel surprising distances for such a small and vulnerable creature.
In the case of the harvest mice we knew the habitat was suitable, some mice had survived 15 years or more however with a small initial release there is the danger of a limited genetic pool making the animals more vulnerable to disease and local extinction. The reason for their initial loss however is due to suitable habitat being lost and changing farming practices. Most harvest mice don’t live in cornfields or hay meadows but for those that try you can see why a scythe is less of a danger than a combine harvester or disc mower. At East Chevington the acres of reedbed provide plenty of safe habitat and yet this is still detached from the next suitable area.
All this goes to say how vital it is to have connectivity between wilder areas: whether that is in the form of hedges, ideally not just a line of scrappy hawthorns but a healthy and thriving hedge, or in streams and rivers that are not canalised and dredged or buried out of sight.
Days like my recent two feel extremely positive, an attempt to redress a lost balance, but at the same time it goes to show how far we have slipped from a country where wildlife, in all its diversity, had a chance to thrive. If we had asked our great grandparents whether we would have to be acting to save creatures such as the harvest mouse or water vole they would have been baffled. It just shows how much has gone in such a short time.
Head of Conservation
Northumberland Wildlife Trust