Ratty Returns!! Water Vole Populations Up In Key UK Areas, Though Overall Decline Persists

Water voles continue to decline in their distribution across Britain but there are signs of recovery in some regions, with populations bouncing back in 11 key areas, according to a report. The river-residing mammal, which inspired Ratty in the Wind in the Willows, has revived in number in parts of Yorkshire, Oxfordshire, Hertfordshire and East Anglia thanks to targeted conservation work.

Reintroductions, habitat restoration and, crucially, the effective eradication of American mink – the non-native predator responsible for water vole population crashes – are helping the creature recover from historic lows, finds the National Water Vole Database Project report. The Wildlife Trusts study found that in 2006 water voles occupied 1,071 10km squares across England, Scotland and Wales. In 2022, water voles were counted in just 652 10km squares, the lowest on record and a decline in range of 39%. These declines are on top of a catastrophic 94% estimated reduction in distribution between 1900 and 1998.

The study also reveals that the area occupied by American mink between 2013 and 2022 is 308 10km grid squares smaller than their total historic extent – suggesting that efforts to reduce the non-native predator are working. The report also identified 11 new “regional key areas” for water voles – areas greater than 35 sq km where resilient water vole populations are found. A further 30 existing regional key areas expanded in size, while 12 retained their previous size.

Ali Morse, water policy manager at the Wildlife Trusts, said: “The data is giving us a very clear message. The overall national picture is one of decline due to the destruction of natural habitats and predation by the non-native American mink. However, water vole populations will thrive when the right conditions are created. It’s heartening to see that we can still rescue Ratty, if we all plan well and coordinate our efforts.

EDIT

https://www.theguardian.com/environment/2024/dec/23/water-voles-bounce-back-in-key-areas-but-distribution-across-uk-declines