The recovery of UK otters in the last few decades has been a great success story.
During the 20th century otter numbers crashed - due to factors including loss of habitat, pollution and persecution. However, changes to the law on pesticide use and hunting, and the cleaning up of our waterways have seen these charismatic mammals make a comeback, so they can now be found in every county in England.
Previous national otter surveys have shown the Peak District and South Pennines to be one of the last places in the country to be re-colonised. Looking for signs of otters in a co-ordinated way across the area should provide a baseline against which to monitor future otter population recovery and changes in distribution. It may also help to answer the question: How far into the uplands can otters be found?
Water voles, meanwhile, have suffered a catastrophic decline in recent years.
As much as 95% of the UK population has been lost in the last 70 years. Fortunately, studies have highlighted that uplands areas – like those in the Peak District and South Pennines – may be a remaining stronghold for these rodents.
This may in large part be due to the absence of the American mink in these areas. Mink are a non-native invasive species, and are a major predator of water voles. Interestingly, it is thought that mink are doing less well in areas where otter have recovered.