Beaver Management Report - January 2023 to April 2024

Summary

• The report covers a 15-month period from January 2023 to April 2024, with annual licence returns now aligned with management activity from mid-August to end of March.
• There was significant progress with beaver translocations to both Cairngorms and Loch Lomond National Parks as well as multiple reinforcements within range in Tayside, Forth and Knapdale. In total 40 beavers were released in Scotland and 34 animals were moved to licenced enclosure projects in England.
• Records for beavers in new areas point to the population continuing to expand naturally in parts of Tayside, the wider Forth area, into West Lothian and Fife, with some evidence of dispersal from Knapdale and in the Highlands. A survey of the beaver population (excluding Knapdale and Spey) is planned for winter 24/25 to provide an up-to-date assessment of beaver populations.
• In total 85 beavers were removed from conflict sites over a 16-month period, with 90% of these being by trapping rather than by lethal control. This compares with the proportion trapped being 42% in 2022 and 28% in 2021. A total of 122 dams were removed under licence in the same period.
• The number of beavers being lethally controlled (8 over this period) is significantly reduced from previous levels and reflects the effort that has gone into supporting trapping and land managers willingness to try this approach first. Whilst these low numbers are very welcome, it is important to highlight these levels may not be achievable every year, given the population is continuing to expand, that trapping is dependent of the requirement for beaver removal and the feasibility of trapping at these locations and translocation on the availability of release sites.
• Currently there are more release sites available in the Spey catchment and in licenced projects in England, but a forward plan for future release sites is being developed both within the approved range and in new catchments.
• Over this period NatureScot have responded to an increased number of beaver mitigation enquiries again, possibly reflecting the expanding population. We have provided advice, used and promoted well-established mitigation techniques and have trialled new approaches.
• This period was also marked by a series of damaging storms, which brought extreme flood events impacting on communities and land managers at very significant costs. Beaver activity has likely contributed to some of the damage. We discuss the survey techniques we have been trialling to improve detection of beaver burrows and the management challenges.

Introduction

We have published a report on beaver management each year since beavers became European Protected Species (EPS) in 2019. Previously beaver licence returns were due at the end of January covering the preceding calendar year (January to December). Since 2021 beaver licences have not operated during the kit dependency period; from 1 April to 16 August (an exceptional licence is now needed during this period). Hence previously beaver management reports covered two truncated periods Jan to March and August to December of each year. Last year, the licence returns period was moved to 17 August through to the following March (31), with the return deadline moved to the end of April. Consequently, the date of publication of this report is later in the year than it has been in previous years. It also covers a 15-month period to provide continuity with the last report produced for the calendar year 2022. Hence here we report on beaver management between January 2023 and 31 March 2024. 

The report follows the same format as last year, with themes based on those of Scotland’s Beaver Strategy. However, progress with Scotland’s Beaver Strategy will be the subject of a separate short report summarising Strategy progress over the last year. This report is expected to be published by the Scottish Beaver Advisory Group later this summer. 

The period from autumn to winter 2023/24 was notable for a series of damaging storms and was one of the wettest Oct-Mar periods on record in the UK and affected the eastern board of Scotland in particular. Successive floods compounded impacts on agriculture and housing causing extensive socioeconomic and psychosocial health concerns. The contribution that beavers have made to the flooding has been raised by farmers with several instances of flood bank breaches being observed in areas of high beaver activity. We explore some of the work NatureScot are involved with to better understand beaver burrowing impacts, against a backdrop of increasing flood frequency and intensity.

In 2023/24 beaver records were recorded for the first time in the Eden catchment in Fife, around Carnoustie, extending to the north in Strathardle, around Stirling and in the Avon catchment in West Lothian and in the Trossachs around Loch Con and Loch Ard. This suggests that the beaver population is continuing to expand naturally in numbers and distribution; mostly to the east arising from the populations in Tayside and the Forth, with movement towards the headwaters in the west. However, dispersal from Knapdale was also observed with one animal being recovered by SSPCA in Kintyre, reportedly 60 miles from its previous known location (it had been ear-tagged during the Knapdale Reinforcement Project). There were also records of beaver activity on the Oich in the highlands, which could represent a long-distance movement from the nearest known beavers on the river Glass in the Beauly catchment.

The last survey of the beaver population in Tayside and Forth was carried out over the winter of 2020/21. At that time there was estimated to be 251 active beaver territories equivalent to roughly 954 animals (range 602-1381). This was a 30% annual increase since the previous survey in 2017/18 and that rate of increase was expected to continue. Since then, we have had a further three years of breeding and the population might now be expected to be around 2000 animals. A survey of the beaver population (excluding Knapdale and Spey) is planned over 2024 and 2025 to provide an up-to-date assessment of beaver populations in Tayside and surrounding catchments. This is expected to help us better understand what is happening in terms of the number and distribution of territories, group size and management influences, at the same time as refining a sampling regime and protocol for future beaver surveys. 

Conservation translocations (and reinforcements)

The first translocation to the RSPB Reserve on Loch Lomond took place at the end of January 2023. This was regarded as a reinforcement with beavers previously having reached the reserve through natural dispersal from the Forth. However, the licenced release means Loch Lomond is now regarded as a new catchment that is within beavers’ natural range in Scotland. 

In 2023 NatureScot consulted on (Strategic Environmental Assessment) Environmental Reports for the river Beauly and Spey catchments. We also published our Habitats Regulations (1994) Assessments (HRA) of beaver releases in these catchments (Beauly, Spey).

The Cairngorms National Park Authority carried out extensive stakeholder engagement and submitted an application for beaver translocation to the upper Spey catchment in October. A licence was issued in December 2023 with the first two releases happening the same month on Rothiemurchus and Wildland Cairngorms Ltd. Since then, a further four family groups have been released including three on RSPB Insch Marshes. The Cairngorms releases are viewed as very significant in terms of beaver restoration; bringing beavers back to some of the most extensive and most suitable habitat in the country, with benefits expected for biodiversity and water resource management. 

The Cairngorms National Park Authority application details a comprehensive Monitoring and Mitigation Plan. A partnership, the ‘Cairngorms Beaver Monitoring and Mitigation Plan Group’ has been formed to oversee delivery. The licence permits up to fifteen beaver family groups to be released with a view to establishing a self-sustaining population in the Spey. The Cairngorms National Park Authority are leading on engagement within land managers in the National Park and co-ordinating the sequence of further release sites. NatureScot have committed to work with the Park Authority and local interests to address any potential issues that may arise as beavers become established in this new catchment.

• From a legal perspective (W&C Act 1981 as amended) beavers released anywhere in Scotland are regarded as a ‘former native’ species outwith their native range and hence their release can only be carried out under licence.  Beavers are European Protected Species in Scotland, but the concept of ‘natural range’ (EC Habitats Regulations Guidance) only recognises populations that have been formally reintroduced.  Hence we have taken a policy position in line with the EC Habitats Regulations Guidance to recognise authorised populations and catchments where licensed release has already taken place as forming beaver’s natural range in Scotland. Hence in considering the definition of ‘within range’ we are essentially talking about catchments where there have been licensed translocations or reinforcements, or as in the case of Tayside and Knapdale the population has been officially permitted to remain, i.e. rather than a definition based on current distribution.

There was also further engagement regarding the proposal to release of beavers to the Beauly catchment. A revised proposal was outlined which focuses on the Forestry and Land Scotland land holding in Glen Affric, with Trees for Life leading on the public engagement. The engagement period was extended and included further consultation with local stakeholders. Forestry and Land Scotland are currently considering the detail of the engagement report along with other representation made to them. 

NatureScot produced guidance on beaver translocations in 2022 (interim guidance – and then guidance for applicants, consultees and interested parties). Since the interim guidance was published Scotland’s Beaver Strategy has been published with a vision for beaver restoration to appropriate areas of Scotland; with management and mitigation in place to protect assets and interests. The interim guidance was focused on the support available to those wishing to undertake translocations to new catchments, reflecting the policy change to allow this at the time. The guidance for applicants, consultees and interested parties recognises there is also further potential for ‘within range’ translocations.

In the last year NatureScot have been approached about various proposals and are aware of the various nuances and considerations for different scenarios.  For example, we recognise there are differences in what might be required for a ‘within range’ proposal where there have already been regulatory assessments and engagement/ awareness of beaver effects and mitigation options compared with new catchments where these processes have not taken place. There are also areas where beavers are naturally colonising that have not been subject to the same processes. Proposals also need to take account of the proximity to existing beaver territories, both to avoid territorial disputes and to avoid establishing isolated populations that would require ongoing population and genetic management. Hence, we plan to update our guidance to reflect the range of different circumstances we now have in Scotland. 

We are aware the resources required to carry out stakeholder engagement can be viewed as a barrier to land managers who may be interested in hosting beavers. However, we are also aware of the growing evidence of the importance of the social dimension of reintroductions and translocations. In setting out these licensing requirements, NatureScot are seeking to ensure that stakeholders have been properly engaged in the proposals; have been able to ask questions and there are clear plans in place for mitigation or management of potential conflicts that may arise.

We have also been looking at the regulatory processes involved in translocations and if we can streamline them to enable beaver restoration to be considered in more new catchments. Reflecting that the SEA consultations we have carried out have not produced a large number of responses and that the conclusions reached in the Environmental Reports undertaken to date have been broadly similar, we have carried out an SEA screening for the River Ness and River Lochy catchments (the Great Glen). The consultation authorities have approved this approach and our assessment in this case. Hence going forward we would propose to use a screening assessment to examine if the range of receptors and interactions would be expected to be similar in other new catchments. However, if following this screening exercise there are different issues identified or the scale of interactions is expected to be different from those previously considered, we would complete and consult on a more detailed Environmental Report. We are also seeking to complete a Habitats Regulations Assessment (1994) at a national scale, such that assessments would not need to be carried out on a catchment-by-catchment basis, however, this is a considerable undertaking and is expected to take another six months to complete.

We published a national assessment of all 138 mainland river catchments in 2022 with a view to informing the suitability of different catchments for beavers. However, which new catchments are prioritised for assessment work, will be guided by where there is support and interest from communities and land managers. Our guidance highlights the preference for strategic applications, i.e. with multiple release sites where the beavers would establish a self -sustaining population. Where the potential for multiple releases may not exist on a single landholding, there could be opportunities for interested parties to work together to submit an application. We log any expressions of interest and can help to bring together interested parties to develop strategic applications and share the work of engaging with others. Hence, we encourage those that may be interested to contact [email protected] to note interest. We are happy to offer informal discussions to interested parties.

Last year also saw multiple beaver reinforcements to catchments where beavers have already been sanctioned or where there have been licenced releases (i.e. ‘within range’). This included releases to Forestry and Land Scotland land within Tay Forest Park, Knapdale Forest and Queen Elizabeth Forest Park. Further releases to Argaty Red Kites and to RSPB Loch Lomond. We consider there are further opportunities for beaver release to low conflict sites within these catchments (Tay, Forth, Knapdale, Loch Lomond). Again, we would encourage land managers and communities to come forward with proposals for suitable low conflict release sites. 

NatureScot has continued to provide financial support for the practical elements of licenced translocations/ reinforcements. This has been delivered through a Partnership Agreement with the Beaver Trust and Five Sisters Zoo.  Trapping, transportation, captive care and health screening of animals has been carried out to an agreed protocol delivering high standards of animal welfare. In the financial year 2022/23 NatureScot contributed £30,000 towards the costs of beaver translocations, in 2023/24 our contribution was £87,500, reflecting the increased scale of translocations taking place.

Management and Mitigation

Beaver mitigation

As in previous years NatureScot have provided a Beaver Mitigation Scheme to land managers through both staff resource and contractors. The NatureScot beaver team logged 84 beaver mitigation ‘cases’ between January 2023 and March 2024. A ‘case’ includes requests for advice on beaver impacts and for mitigation works. Sixty percent of these were new cases, and 40% on sites where NatureScot has had previous involvement. Seventy-six cases (91%) were from the Tay, 7 (8%) were from the Forth and there was one request for advice from the Beauly catchment (1%). Despite being for a 15-month period, the number of mitigation cases is more than double that of 2022. This could reflect an increase in people being aware of beaver signs and beaver presence, an increased awareness of where to seek advice, but may also reflect population increases.

The primary beaver behaviour causing negative impacts, was recorded for each ‘case’. Dam building was the most common impact recorded (48%), as was the case in 2022. Bark stripping/tree felling (33%) was the next most commonly reported impact and third was burrowing (17%). Burrow entrances are normally below the water line and often go undetected until they collapse. Collapsed burrows were reported to have caused problems for agriculture, infrastructure, for riverbank erosion and amenity in this period.

The assets affected by beaver activity were recorded as follows: tree damage/loss (37%); crop damage/loss and loss of grazing (24%); infrastructure (16%) and bank erosion/collapse (14%), with compromised septic tanks and property impacts collectively making up the remaining 4% of cases. In 5% of cases no impact was recorded. 

For most enquiries regarding impacts on trees, NatureScot provide advice enabling the landowner/manager to assess and manage impacts for themselves. Where there is a clear public interest, tree protection using either weldmesh or WOBRA deterrent paint, is carried out under the NatureScot Beaver Mitigation Scheme. Three new flow devices were installed, and existing ones were maintained. Flow devices continue to provide an effective co-existence solution in cases where a compromise can be reached between the beavers and the land manager regarding water levels. Water level monitors also continue to provide an alert to the presence of dams in sensitive locations. Hence there continue to be a small number of tried and tested beaver mitigation techniques applied that are effective and relatively inexpensive. We have continued to explore more novel approaches such as the use of water gates (see case study) and the use of willow whips in river-bank protection. Network Rail have experience of a number of cases involving hard engineering of rail embankments.

In the financial year 2022-23 NatureScot spent £160,000 on beaver mitigation works. A significant part of this (£87K) was on the CivTech project detailed in the research section of this report. A larger part of the costs of this project was met by Scottish Government CivTech. Other costs include contracts for the provision of advice and mitigation to land managers, equipment costs including fencing installation (see case study) and professional services such as eDNA analysis for salmonids, and the contract to deliver beaver post-mortems.

In the financial year 2023/24 the mitigation budget spend was £100,000. This included further work on the CivTech project and the trialling of additional technologies to survey for beaver burrows. Again, other costs were on the provision of beaver advice and mitigation, water gate construction (see case study), equipment such as water level monitors and contracted services including electrofishing surveys in support of mitigation projects.

Mitigation Case Study - Water Gate Trial

Some areas of Prime Agricultural Land have merited beaver removal under licence since beavers became EPS. A key part of the mitigation scheme aims are to trial innovative solutions that are appropriate to the situation. Water gates have been proposed as a possible solution in such areas of high conflict with agriculture that will require ongoing beaver removal. The water gate concept is simple; to establish a barrier to beaver movement in the watercourse with associated ‘wing/ fencing to prevent beavers walking around the barrier overland. The approach is also dependent on their being a discrete ‘defendable’ watercourse rather than an interconnected network of drainage channels. Beaver exclusion with water gates is not a technique that is widely used to reduce conflicts in Europe or the US, but NatureScot have undertaken to trial this approach in these specific circumstances. 

A trial has been established in one such area on a tributary of the river Isla, to assess if the water gate can successfully exclude beavers from the upstream reaches or at least reduce the number of beaver removals and to learn from this experience. 

The process of installing a water gate is, however, complex and can require baseline surveys, flood risk assessment (local authority engagement), consultation with SEPA and potentially a CAR licence (Water Environment (Controlled Activities) (Scotland) Regulations 2011), land owner agreement and agreement around the maintenance of the structure, consideration of impacts on other species and beaver welfare, design works, installation and post-installation monitoring. 

A key consideration has been the risk to salmonids, in particular Atlantic Salmon that are classed as an (IUCN) endangered species and for which the Tay is a Special Area of Conservation. The Environment Agency guidelines on grille spacing for fish passage suggest the spacing should be a minimum of 200mm for salmon and sea trout and 150mm for brown trout. Conversely the maximum grille spacing considered to prevent beaver passage is 100mm from experience of beaver escapes from enclosure projects. Hence there is a fundamental incompatibility for designing a physical structure that achieves both aims. A group of fish and beaver experts met to consider alternative designs and considerable stakeholder engagement and survey work was carried out to quantitively assess the salmon populations in reaches up and downstream of the proposed water gate location. In this case there were a very small number of juvenile salmon upstream, but also other barriers to fish passage such that salmon numbers were very low and habitat quality very poor above the planned water gate site. Hence NatureScot decided to proceed with the trial with a grille bar spacing of 15cm at this location. This spacing is a compromise; seeking to prevent most beavers from crossing, whilst minimising impacts on fish passage. Agreements were worked up with land managers and in this case Scottish Water due to a pre-existing pipe bridge structure at the site.

The in-stream grille was fixed to the existing concrete and a gated vertical railing was fixed to prevent beavers from climbing up and over the concrete platform, i.e. the design is specific to the location. Wing skirt-fencing was erected using skirted ‘beaver fencing’ either side of the burn, 250 either side downstream of the water gate to prevent beavers from moving upstream over land or burrowing underneath. The fencing includes an otter pass. Automated water level monitors were installed above and below the water gate, to indicate if there has been a build-up of debris that needs to be removed to reduce flood risk and the impediment of fish passage.

Following the installation of the water gate, beaver trapping was conducted and will continue (outwith kit dependency period) until monitoring shows there are no more beavers living upstream. A trail camera has been set up to monitor beaver interactions with the structure. To date beaver, otter and badger have been recorded, with no evidence of beavers passing through the structure. NatureScot will maintain the structure and conduct annual fish surveys for the five-year trial period over which its efficacy will be assessed. Two further water gate trials are also still being explored, though for the reasons set out, there are considered to be relatively few situations where water gates are likely to be appropriate.

Beaver licensing

The number and extent of beaver licences that were current in 2023 (n=59) and 2024 (to March) (n=54) was again similar to previous years. The breakdown of licensing purposes is shown for 2023 in Table 1. Of the licences that were current in 2023, one was revoked and ten expired and were not renewed hence were not operating in 2024. A number of these had beaver management actions carried out in the previous year and no longer needed a licence and some of the others chose not to re-apply when licences expired. There were six new licences issued in the first three months of 2024, all for dam removal only. 

The majority of the two-year beaver licences which were issued in 2019 when beavers became EPS and were renewed in 2021 expired in 2023. Those seeking a new licence were asked to submit an application form for the first time. This better aligns the approaches for other species licenses and importantly ensures that NatureScot has current information on which to determine licences. Any new sites are visited by NatureScot staff or specialist contactors to provide advice and assess the potential for mitigation ahead of a new licence being issued. Site visits are not necessary where experience of impacts is well established and known to NatureScot staff. 

Of the 59 licences active in 2023 returns were received for all but seven licences. These had all expired/ or been revoked during that year and a new licence had not been applied for/issued. Of the 52 returns received, actions were taken under 24 licences. In eight of these sites, no action was taken by the licence holder, but trapping occurred under the licence held by specialist trappers in the Beaver Trust. Hence no licenced actions were taken on 20 (33%) of the sites with licences in 2023.

All of the 54 current licences in 2024 have provided a return. Thirteen had taken action and trapping was carried out at a further three locations under the separate licence held by specialist trappers, i.e. actions were taken on a total of 16 sites.

A total of 77 animals were trapped under licence. Of these, 51 were trapped in 2023 and 26 in the months Jan to April 2024. This included five animals trapped early in the kit dependency period in April 2024. In this case an exception was granted to the licence held by specialist trappers to continue trapping into April 2024 to enable the remainder of two family groups to be trapped.

Sixty-nine animals were trapped on sites where NatureScot licences have been issued and a further eight animals on three sites under the licence held by specialist trappers. Such sites are an exception, but still require that the licensing tests which support the case for beaver removal are fully examined and met. Generally, these are circumstance where trapping is considered to resolve the conflict such that the land manager/property owner would not have a need for an ongoing licence. Trapping took place at a total of 18 conflict sites over the 16-month period. 

In total 85 beavers were removed from conflict sites, with 90% of these being by trapping rather than lethal control. This is a large increase in the proportion of those removed being trapped rather than subject to lethal control; from 42% trapped in 2022 and 28% in 2021. Trapping was attempted in three out of the four locations where lethal control was subsequently carried out. The overall level of removal is also slightly reduced from 108 in the 12 month period in 2022 and 120 in 2021.The reasons for this are not known, but could include the actions taken in previous years requiring less action over this period, or the change to the reporting period could have resulted in under-reporting of actions taken. Some of the licence holders that did not seek to re-apply for licences could also account for some of the difference. 

Previous reports have carried out an analysis of the impact of removals on the beaver population based on matching territories to survey information from the 2020/21 survey. As we are now three years on from this survey, the use of this data in such analyses becomes more questionable. The levels of beaver removal have been lower this year and we are planning to conduct another beaver survey this coming winter, hence it is proposed to continue to review the impact of management based on this new survey information once it is available.

The levels of lethal control are much reduced from previous levels and reflect the effort that has gone into trapping by the Beaver Trust team working with land managers and from NatureScot staff helping to co-ordinate trapping requests from licence holders. The low numbers of beavers being killed is obviously very welcome, but it is important to highlight that these numbers may not be achievable every year given the population is increasing and expanding in range. Trapping also depends on the requirement for trapping and the feasibility on given sites. There are currently still opportunities for beavers to be moved to other licenced translocation projects, but this is unlikely to be sustainable indefinitely.  

Trapping is financially supported by NatureScot where the beavers are going to licenced translocation projects in Scotland. Where animals are going to licenced projects in England and Wales, the costs are supported by those projects. In either case, it is carried out at no cost to the land manager. Trapping is ongoing at multiple sites and technology allows for real-time monitoring of traps. However, in order to ensure that requests for trapping are met, it is helpful to get requests early in the trapping season. There were a number of requests for trapping in locations where beavers were well established in March 2024 which were likely to contain family groups. NatureScot staff took the decision not to trap in these cases to avoid having to extend the trapping into kit dependency period and the risk of trapping pregnant females and having to take them into captive care. However, in these cases trapping has been scheduled to start after kit dependency in August. 

One exceptional licence was issued during kit dependency in 2023 for dam removal for public health and safety reasons and to date there have been none in 2024. Exceptional requests for trapping and mitigation works have been approved under the licence held by Beaver Trust specialists during kit dependency period. 

Six animals that were trapped were euthanised due to pre-existing injuries with a hopeless prognosis for recovery (fractures, infected bites from other beavers and two with severe lacerations suspected to be from barbed wire or potentially other beaver bites) and one animal died in captive care for which the cause of death was given as acute necrotising typhlocolitis.

Table 3 illustrates where beavers were released in 2023 and the early part of 2024. The figures reflect the year of release as some trapping and releases span the calendar year end. 

Over the period Jan 2023 to April 2024, 40 beavers were released in Scotland. This includes two animals rehabilitated by SSPCA and two animals trapped in earlier years and held in other enclosure projects and one within catchment release. Thirty-four animals were moved to licenced enclosure projects in England. 

There remains to be known demand for beavers to licenced projects in England, though Natural England are now prioritising sourcing beavers from enclosure projects in England where numbers need to be managed. The policy on wild release in England and Wales remains under consideration by respective Governments. The CNPA licence allows for a further nine families to be released. NatureScot are engaged with other parties interested in beaver translocations, with a view to having a forward plan for release sites.

All licence returns have been subject to compliance checks. Four licence holders submitted returns which included dates for dam removal in the kit dependency period have been contacted and reminded of the need to apply for exceptional licences during this period. All other licence conditions appear to have been followed and accredited controller returns indicate good compliance with the Code of Practice. Licences issued in 2023 all had a new condition that requires NatureScot to be notified when a beaver has been shot and either is available for collection for post-mortem or was not able to be safely retrieved. Some licences expiring in 2023 did not have this as a condition, but from August 2024 all licences will have this as a condition. This should enable more carcasses to be retrieved and better matching of beavers found shot reported by the public with licenced control. Only one carcass shot under licence was collected (two were reported) and a further two were collected by Police Scotland having been reported by a member of the public. In part the low level of carcasses submitted reflects that fewer animals were shot over the period. However, there has been further engagement with licence holders to highlight the importance of submitting carcasses to demonstrate that lethal control is being carried out according to the Code of Practice.

A total of 122 dams were removed under licence in the 15 months January 2023 to March 2024.

Research and Innovation

CivTech Challenge on burrow detection

NatureScot continued to participate in the Scottish Government’s CivTech 7 Challenge scheme, working with JBA Consulting and Storm Geomatics to detect beaver burrows and assess the risk they present to other land-uses. The Challenge involved trailing an approach to surveying rivers with side-scanning sonar to detect burrows. An App was developed to allow visualisation of the sonar imagery alongside manually inputted site attributes, providing a standardised approach to risk assessment. This ‘RiverEye’ App is now used by NatureScot staff and contractors to collect data during beaver site visits and to help assess burrowing risk. In 2023, sonar surveys were tested at several locations in Tayside. This was followed up in early 2024 with a survey on the river Isla (Figure 4 for example of sonar imagery). This latter Isla survey was matched with a foot survey (Figure 5) looking for visible beaver burrowing activity and an experimental drone-based radar scan over part of the same survey area. The intention is to compare the data gathered by these three methods to establish their limitations and where and how they could be used as complimentary techniques. Whilst the CivTech project has now concluded this analysis is ongoing.

The second half of 2023 brought unprecedented rainfall to parts of Scotland. The flooding caused extensive damage to agriculture, to property and to infrastructure in many eastern parts of Scotland. In particular, there were multiple breaches to man-made flood banks in Angus, Perth and Kinross, Speyside and Aberdeenshire. Scottish Government offered a grant to farmers to help repair flood banks damaged by the flooding; up to a maximum of £30,000 per farm business. Grants were awarded to a total of 57 business illustrating the extent of the damage. Beavers are not present in all of these areas, however, some of the areas affected are known to have high levels of beaver activity. NatureScot are aware of eight flood bank breaches during Storm Babet that farmers have attributed to beaver impacts. There are likely to be multiple factors involved in flood bank breaches including the extreme weather, sandy substrates, river modifications and prevailing river processes, however, beaver activity is likely to have contributed to flood bank weaknesses (as illustrated in Figure 5).  Such events have raised the awareness of the risk of very serious impacts against a backdrop of an increasing frequency and intensity of flood events.

Similar research into methods of burrow detection has been ongoing in the Netherlands and Germany where many regions occupy land below sea level that is protected by levees. Here water boards have developed protocols based on assessing risk (beaver territories/ risky assets), performing regular inspections and repairs, considering the need for beaver removal or in specific locations reinforcement of banks. Experience from other parts of Europe suggests there are fewer conflicts with beavers where embankments are set further back from the river. Some countries are also supporting farmers to allow seasonal flooding for the benefit of downstream communities. Flood resilience approaches that make more space for the river are likely to provide more sustainable solutions but will be costly to implement and will have implications for land use and hence may not be appropriate in all places due their importance for food production. Conversely ongoing beaver removal from extensive areas with flood embankments will be challenging.

Postmortem details

In total, 27 dead beavers were reported to NatureScot over this period, of which 16 were retrieved, including three collected by Police Scotland. Thirteen post-mortem reports have been received at the time of writing (two with provisional findings only). Post-mortem findings from the beaver shot under licence and collected by NatureScot (see above) are not available at the time of writing. 

Seven were female (six adults and one juvenile) and six were male (two adults and four juvenile). Causes of death were: shot four; vehicle strike four; blunt trauma (possibly vehicle strike) two; infection or disease two; predation one (a c.10-month-old kit killed by an otter). There was no indication of illegality with any of the beavers that were shot, and no welfare issues identified from the postmortem findings. Of the two that died from infection or disease, one was a result of an infected foot wound with suspected septicaemia, and the other was attributed to Salmonellosis. 

Five of the beavers were tested for common pathogens: None tested positive for Cryptosporidium or Giardia, one tested positive for Salmonella (see above) and one for Yersinia (thought to be a contaminant and not an infection however). All five carried the species-specific intestinal parasite Stichorchis subtriquetrus.