Beavers released in York Moors transformed site ‘in ways we never imagined’
Releasing beavers as part of a licensed trial in the North York Moors has had a positive impact, helping to reduce downstream flooding and enhance biodiversity, according to new research from the University of Leeds.
Two beavers were released in 2019 into an enclosure in Cropton Forest where natural flood management had already taken place to try to reduce the flood risk to villages downstream. The trial was led by Forestry England and licensed by Natural England.
Researchers worked with volunteers to take comprehensive measurements at the site before the beavers’ release and then monitored their impact over a five-year period. The results are published in the academic journal Ecohydrology.
Lead author of the paper, Professor Mark Smith of the University of Leeds, School of Geography, said: “This is the first time so many different things have been measured at the same site, including before and after beaver release comparisons. The site was transformed by the beavers in ways we never imagined."
Over the five-year period the beavers constructed six dams, one of which was the biggest in England. The beavers’ efforts augmented the impact of existing natural flood management infrastructure, leading to lower peak flows in the river which were slower to arrive downstream and contained smaller volumes of water.
Aquatic plant diversity also increased, and fish and amphibian species richness was higher than in a neighbouring stream. The researchers also found evidence of an increase in bat populations at locations and times that corresponded with beaver activity.
Beavers have been absent from the British landscape for centuries, but wild beaver populations have returned in recent years as part of reintroduction schemes, including releases into monitored enclosures.
The Eurasian beavers from Tayside in Scotland were released into the enclosure at Cropton Forest in April 2019. They were already a pair, and 11 kits were born in the enclosure over the trial period. To manage the population, four older juveniles were relocated to support other projects across England.
Camera trap footage revealed that the beavers lived in an extended family group with just one dominant breeding pair. All beavers were observed using the whole site. Species recovery officer for Forestry England in Yorkshire, Cath Bashford said: “Being closely involved in bringing the beaver back to Yorkshire for the first time in several hundred years has been incredible.
“It has been amazing to watch the changes that the beavers have made to the site throughout the trial and the species that have moved in and thrived alongside them. They have created a complex wetland habitat connecting the river with the floodplain, holding back water in the upper catchment, bringing benefits in times of drought and slowing the flow in times of flood.”