Wetlands created by beavers have 45% more butterflies than those created by people, a Butterfly Conservation ecologist has revealed.
The study also showed that beaver wetlands have 29% more hoverfly species and 119% more hoverfly individuals.
Both groups of insects pollinate a range of plants, highlighting a potentially unforeseen benefit of beaver reintroduction.
The study was carried out by Butterfly Conservation ecologist Patrick Cook for his PhD at Stirling University.
Mr Cook hopes his results will help beaver wetlands to be seen as a new potential strategy to reverse decades of wildlife decline, but also warned that landowners need to be incentivised.
Mr Cook said: “Pollinators such as bees and butterflies are undergoing widespread and dramatic declines in the size of their populations. This has negative effects on the delivery of pollination, but it is also leading to the loss of some of our most charismatic species from the countryside. We urgently need methods to reverse these declines.
“Currently in the UK, most agri-environment subsidy schemes support human pond creation, with little financial incentive for landowners to accommodate beaver wetlands – despite the potential boost in pollination services. This position needs to change if we are to benefit from the buzz, flutter and hum of pollinators that beaver wetlands promote.”
Mr Cook and fellow researchers from Stirling University carried out six pollinator surveys from May to August 2023 on beaver wetlands at Bamff Wildland, a rewilding estate in Perthshire, and on manmade ponds at two neighbouring private farms.
The team counted the number of bees, butterflies, hoverflies, moths and flowering plants, and the number of species.
They also recorded which insect species were visiting which flowers, and found that the beaver wetlands had a higher overall number of insect-plant interactions (336 interactions involving 38 species) than human-created ponds (231 interactions with 34 species).
Mr Cook added: “Our work adds further important evidence of the beneficial effects of beaver wetlands for wildlife, in this instance pollinators.
“If we want to realise these benefits, we need to go beyond removing dams and incorporate these wetlands fully into agri-environment schemes to support landowners with beavers on their land.”
Beavers were once widespread across the UK and their dams helped shape the landscape, but they were hunted to extinction in the 16th century.
Numerous organisations have campaigned for reintroduction of beavers to the UK, and in recent years legislators in Scotland and England have granted licences.
The first official release of beavers into the wild in Scotland was carried out by the Scottish Wildlife Trust at Knapdale Forest in 2009. The first official release of beavers into the wild in England was carried out by The National Trust at Purbeck Heath in Dorset in March 2025. Other groups have released beavers onto private land.
[Note from Owl: beavers living wild in the river Otter were first reported c. 2008. Breeding families were confirmed in 2014. Only a public outcry, led by independent councillor, Claire Wright, stopped them being summarily culled (the Defra default policy) . A formal River Otter Beaver Trial was then conducted from 2015 to 2020 to study their impact (driven by the Devon Wildlife Trust). This resulted in the government giving them permanent “permission” to stay in 2020, the first wild beavers to return to England for around 500 years.]
However, farmers and landowners have raised concerns about potential negative impacts.
Professor Nigel Willby, Professor of Freshwater Science at the University of Stirling, said: “On occasion there may be valid reasons to remove a beaver dam. But we should remember that for every beaver dam removed a beaver wetland dies, along with a multitude of attached benefits, including for pollinators.”
Sophie Ramsay, manager for Bamff Wildland, added: “This brilliant new research shows once again that beavers are vital to the agricultural landscape as well as to biodiversity in general.”
The study, Beaver wetlands create a buzz and a flutter for pollinators, was published in the Journal of Applied Ecology, and was funded by the NERC Iapetus programme – a Doctoral Training Partnership funded by the Natural Environment Research Council (NERC) focused on environmental sciences.
Read the study here
East Devon Watch 