Wild beaver population assessment on the River Avon and tributaries.

Published online
10 May 2023
Published by
Natural England
Content type

Harrington, A. & Rothwell, A. & Harrington, L. A. & Dalton, L. & Campbell, R. D.
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Publication language
UK & Scotland & England


Following increasing reports of beavers in Somerset and Wiltshire, Natural England commissioned a survey of beaver activity in the River Avon catchment. Surveys were conducted during January-March 2022 on canoe and foot, covering approximately 280 km of channel length. Beaver activity (field sign types) was recorded at a 10m resolution. The areas covered included the Avon upstream of Bath, including the Kennet and Avon Canal, the Somerset Frome, By Brook, Semington Brook, Biss Brook (all part of the Avon catchment) and upper reaches of the River Brue. A total of 771 beaver activity signs were recorded (Table 1). The Avon and Frome sub-catchments contained the most signs whereas no beaver signs were found on the Biss Brook, the River Brue, or the Kennet and Avon Canal. Recorded signs included 13 lodges, four burrows and 20 dams. Burrows will be under recorded because entrances are usually underwater and detection during the normal higher winter water levels is difficult. 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 ± 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. These beaver territories occupy a total of 4-11% of the available bankside in the watercourses with a typical bankside length of 7.8 km (nearly 4 km watercourse length) per territory. This is higher than reported in some established populations. 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). Few management issues were noted, probably because the population is in the early establishment phase. 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.

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