At least 50 beavers have been living on the Bristol Avon without anyone noticing before, stunned researchers have discovered. And the creatures, which were native to the West Country until the reign of Henry VIII some 500 years ago, are growing in number and expanding their territories across the Bristol and Bath, Somerset and Wiltshire areas.
The existence of the large aquatic mammals was discovered in such numbers after just one family was spotted living on a tributary to the Bristol Avon, between Bristol and Bath, during the Covid lockdown of 2020 and 2021. Bristol Live broke the news that beavers had returned to the area’s rivers in September 2021.
After that discovery, Natural England commissioned a full-scale survey covering 175 miles of the Bristol Avon and its tributaries out into the countryside of North East Somerset and Wiltshire, in January and February 2022. Incredibly, the surveyors discovered what they think are not one, but 13 different established beaver family territories that appear to have been well-established for a few years.
Flashback to Sep 2021: Experts stunned to find beavers living wild on Bristol Avon for first time in almost 500 years
The findings of that report have been released this month, March 2023, and the amazed scientists from Natural England said the beavers had already built at least 20 dams across a number of rivers, including the Somerset Frome, By Brook and Semington Brook in Wiltshire - which are all part of the Avon catchment.
The discovery is remarkable because, until Covid lockdown and the summer of 2020, no one thought beavers were living in this part of the world at all. There had been a few sightings in recent years further into Somerset, and beavers were famously establishing themselves in one valley in Devon, but farmers, environmentalists, the Government and river authorities had started talking about the pros and cons of re-introducing beaver populations into the West Country’s rivers - only to discover that quietly, the beavers already had, and in large numbers.
The first signs of beavers living on the River Avon and its catchment came when the boss of Bristol-based ethical bank Triodos, Bevis Watts, used the covid lockdown to get out on the river in a canoe, and confirmed what dog walkers and local residents had described as being signs that beavers were living on one stretch of the River Avon, during 2021.
That story was remarkable enough, and hit national headlines, because it was the first time beavers had been confirmed and seen on the river since they were hunted to extinction in England back in the 1500s. Avon Wildlife Trust, which had received reports from members of the public during the 2020 covid lockdown that they thought beavers could be living on the River Avon catchment in the Bristol and Bath area and sent Bevis to investigate, said in September 2021 that the discovery of one family of beavers was 'significant'.
Natural England decided to see if there were any more, and sent people to walk the banks and paddle up each little tributary of the Bristol Avon, as far as they could. And they discovered there were loads - a total of 771 beaver activity signs were recorded, mainly on the Avon and Frome subcatchments, while the Biss Brook, River Brue or Kennet and Avon Canal showed no signs of beaver activity.
Those signs included 13 lodges - the above ground ‘nests’ beavers build for themselves - four burrows and 20 dams. And the Natural England surveyors say they think that 771 signs is an under-estimation because burrows are often well-hidden, and there were large parts of the rivers and streams of the former Avon, Wiltshire and Somerset they couldn’t adequately access.
“Burrows will be under-recorded because entrances are usually underwater and detection during the normal higher winter water levels is difficult,” the report from Natural England stated. “From the distribution of beaver signs, 13 established territories are estimated, with an additional six temporary resident individuals, which may go on to form territories.
“Based on the number of territories, a population of around 50 beavers, excluding kits, is estimated (49, plus or minus 13 within the established territories and potentially six other individuals). Not all locations were accessible to survey and therefore it is likely that some territories were not recorded. As a result, the above population estimate is possibly an underestimate,” the report said.
Between four and 11 per cent of all the river bank showed signs of being part of a beaver’s territory. “This is higher than reported in some established populations,” the report said. “It appears that beavers have only become established recently in the area, probably since 2016, though possibly earlier. Most beaver activity appears to be more recent, since 2020,” they added.
The report from Natural England now throws up new questions about whether the previously unknown beaver population should somehow been managed or mitigated for. The reintroduction of beavers has been a controversial subject with environmentalists saying they help with natural flood management and river quality, while some landowners and farmers say they fear land alongside rivers may end up being less useable for agriculture if beavers are allowed to expand their territories.
Natural England’s report implied people need to change their mindset on the issue, now that so many beavers have been discovered and no one had actually noticed before. “Few management issues were noted, probably because the population is in the early establishment phase,” the report stated. “Such issues may increase and a mitigation approach to dealing with these will be needed if we are to live alongside these animals and realise the benefits that they can bring to our environment,” it added.
Read more:
- Help at last for eels who swim 3,000 miles to get stuck in Yate
- The Field Guide to the 14 strangest animals you might see in Bristol
- Slow down to save South Bristol's surprising new otter population, drivers told
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