Challenge: How can technology help us detect beaver burrows in the wild and assess their associated risks to public and private interests?

Key information for applicants

Please note: you must apply for this Challenge via Public Contracts Scotland

Launch date
Tuesday 31 May 2022

Questions may be submitted until
16:00, Tuesday 21 June 2022

Closing date
Midday, Tuesday 28 June 2022

Exploration Stage interviews
Monday 25 July 2022

Exploration Stage
15 August to 2 September 2022

Accelerator interviews
Tuesday 6 September 2022

Accelerator Stage
3 October 2021 to 27 January 2023

Maximum contract value
£650,000

What does this mean?

Q&A session

A live Q&A session was held with the Challenge Sponsor team on Monday 6 June 2022 at 11:00. A recording of the session can be viewed here:

Why does this Challenge need to be solved?

Challenge summary

Whilst a range of wildlife species create burrows and cause potential problems for land managers and for infrastructure, beaver burrows can be particularly problematic as burrow entrances are normally below water level and therefore difficult to detect. Burrows can also be extensive. 

Beavers are a European Protected Species which means they and their breeding sites or resting places are legally protected. Burrows can be simple and used for temporary shelter or may have underground chamber/s used for breeding and resting. Some burrows can become extensive, extending over 10m inland from the water, though the extent of a burrow does not necessarily indicate any problems it could cause. In places burrow chambers may breach to the surface and be covered by woody material or may be associated with a sizable ‘bank lodge’. Bank lodges tend to have the majority of chambers below ground, whereas free standing lodges have the majority of chambers above ground. See definitions and diagrams. Such lodges are easily detected because of their above-ground structure, whereas burrows set entirely underground and that have underwater entrances are much more difficult to find. It is this latter type that is the focus of the challenge. Beaver above-ground activity is normally constrained to within 20m of a freshwater waterbody or watercourse, but can extend up to 50m (Beavers in Scotland Report 2015).

Beavers bring many benefits to wildlife and people because they create wetland habitats and they can improve the diversity of waterside woodlands and river systems. However, some types of beaver activity can create problems in some circumstances, of which one example is the tendency for beavers to create burrows at the water’s edge. A variety of concerns have been associated with beaver burrows and burrow collapse and NatureScot have a catalogue of casework examples. These include burrows contributing to the breaching or bursting of river/ flood embankments leading to the flooding of agricultural land and crop damage, the collapse of burrows with associated risks to farm vehicles and livestock, the public health and safety risks associated with burrow collapse for recreational users of riverside paths (walkers, fishers).  Where river processes are already likely to favour erosion, beaver burrows may present a weak point contributing to bank erosion or scour. Burrows also pose a risk for public infra-structure, be that rail or road earth works. Burrows also pose a potential risk of flooding where there is bunded / impounded water which could be used for a variety of purposes e.g. for amenity, for SUDS, for water supplies or for fish hatcheries.

The existing solutions to such issues vary depending on the circumstances and may include beaver exclusion from the sensitive riverbank or an entire waterway via physical barriers, greenbank or hard engineering solutions to reinforce structures and mitigate beaver impacts, moving vulnerable structures back from the watercourse (e.g. floodbank realignment), or through species licensing of beaver removal by trapping or lethal control. Through the Scottish Beaver Mitigation Scheme NatureScot is keen to develop innovative solutions and to trial approaches that facilitate living alongside beavers.

Because detection is difficult problems often arise before it is known that burrows are present, or that the perception of risk is high because the extent of burrowing cannot be determined without destructive investigations. Combined with detection it is important to determine whether burrows present a risk to inform the need for further monitoring or management intervention. 

How will we know the Challenge has been solved?

The ability to detect and risk assess beaver burrows would principally reduce the following conflicts:

• Reduced risks to the public through proactive assessment of risk to infrastructure

• Reduced damage to crops and embankments for land managers

• Allow species licensing to be better targeted to high risk situations and the perception of risk to be better understood; reducing the need for intervention where the risks are low

Who are the end users of the solution likely to be? title

In Scotland the principal interest is likely to lie with NatureScot as the statutory nature conservation body, with land and fisheries managers, with managers of infrastructure (Network Rail, Transport Scotland, Local Authorities, Scottish Water), with recreational users (e.g. Paths groups) and SEPA in terms of flood risk and environmental protection.

Has the Challenge Sponsor attempted to solve this problem before?

To date the focus has been on developing appropriate mitigation solutions rather than detection and risk assessment.

NatureScot commissioned a survey of the Tayside beaver population in 2020-21. The survey included over 1760 km of connecting water course bank (river, burn, loch etc.) and 1,238 non-contiguous water course over a period of over 220 person-days. Field surveys involved surveying a water course from either canoe or on foot depending on water course suitability and accessibility. The majority of this survey was undertaken on foot. As noted in Campbell et al. (2012), canoe surveys are more likely to reveal more waterside activity (including burrow entrances) with the potential for underreporting inland activity, whilst the opposite tends to be true for surveys on foot. The survey detected 443 burrows or potential burrows. The survey simply recorded their presence as a field sign and did not investigate them further. It is apparent however, that where beavers are present some level of burrowing can be expected and that in some river sections, particularly the river Isla burrowing can be frequent. Such field surveys are only carried out periodically and to date the principal focus has not been on assessing the risk associated with recorded beaver impacts.

NatureScot were partners in a feasibility study of the use of Ground Penetrating Radar (GPR) to detect and image beaver tunnels. It concluded GPR was able to detect tunnels in some situations and in others the site conditions impeded its success (substrate complexity in terms of roots, vegetation etc). GPR was not recommended as a survey tool for large unknown burrow systems, but was considered to be appropriate for monitoring confirmed tunnel systems where site conditions are conducive. 

Will a solution need to integrate with any existing systems or equipment?

ArcGIS

Any technologies or features the Challenge Sponsor wishes to explore or avoid?

Preferably the solution will combine detection and risk assessment.

What is the commercial opportunity beyond a CivTech contract?

Beavers are present throughout Europe and in North America where similar issues associated with burrowing occur. We are not aware of a system for burrow detection and risk assessment elsewhere.

The beaver range in Scotland is naturally expanding and the Scottish Government policy is now to support the establishment of beavers in new areas, hence it can be anticipated that over time beavers and their burrows will extend into other parts of Scotland.

The policy on beaver releases to the wild in England is currently being considered with the outcome of a stakeholder consultation expected this summer. Should releases in England go ahead we can expect interest in a solution to this challenge from equivalent interests there.

Other British mammals create burrows typically; badgers and rabbits may have similar impacts locally on infrastructure. Burrowing mammals occur almost globally in different forms. We have not reviewed the range of impacts and how analogous they may be to the challenges of detecting beaver burrows.

Who are the stakeholders?

• Land and fisheries managers - either directly or via their representative organisations – National Farmers Union Scotland, Scottish Land and Estates, District Salmon Fisheries Boards or Fisheries Management Scotland.

• Network Rail

• Transport Scotland

• Local Authorities

• SEPA

• Beaver Trust – providers of ecological advice, survey and mitigation services.

Noting others will have an interest; e.g. eNGOS, Environment Agency, River Restoration Centre.

Who’s in the Challenge Sponsor team?

• NatureScot – Sponsor, access to survey data and casework reports

• Network Rail – Asset register, site access

• Beaver Trust – Expert advice

• Scottish Land and Estates and / or National Farmers Union Scotland – Liaison with land managers/ expert advice

• Tay District Salmon Fisheries Board - Expert advice.

What is the policy background to the Challenge?

The decision to allow beavers to remain in Scotland came in 2017 - https://www.gov.scot/news/beavers-to-remain-in-scotland/

In 2019 beavers became a ‘European Protected Species’ - https://www.gov.scot/news/beavers-given-protected-status/ and a Beaver Management Framework was put in place through consultation with the Scottish Beaver Forum membership. The Beaver Management Framework aims to balance the desire to allow the beaver population to continue to expand their range whilst allowing significant detrimental impacts of beavers on particular interests to be managed. This framework includes the Scottish Beaver Mitigation Scheme, the species licensing regime, the policy on translocations, the research and monitoring strategy and further work to increase our understanding of the benefits or ecosystem services provided by beavers. 

In November 2021 Scottish minsters announced that they will actively support the expansion of the beaver population into new areas. https://www.gov.scot/news/protecting-scotlands-beaver-population/

NatureScot is currently working with partners to co-develop a National Beaver Strategy which will set out a long-term vision for beavers in Scotland. This will reflect the Scottish Government’s policy to actively promote the expansion of the beaver population with all the associated benefits for nature.