“My experience with beaver waters is that the fish tend to be around the lodges. Wherever you have woody debris you have aquatic invertebrates – aka fish food. Beaver are very willing to do the work of fisheries trust employees for free!” Duncan Pepper, Fishinguide Scotland
The history of beavers in Britain
Beavers once roamed across our countryside, shaping the landscape and waterways, providing habitat for a huge abundance of fish, birds and insects.
- Native to Britain – beavers once covered the northern hemisphere from North America to the Arctic Circle, including the whole of Britain.
- Hunted to extinction – beaver glands contain salicylic acid from their willow diet, which was prized as a medicinal cure-all. A single gland could equal a year’s wage for a mediaeval worker. Their fur is also extraordinarily soft and warm and in high demand for coats and hats.
- Evolving alongside British wildlife – fish, insects, amphibians, mammals, birds, trees and plants evolved alongside beavers for millions of years. Many species rely on the habitats and food sources created in beaver wetlands.
- Part of human history – beaver pools provided early people with places to hunt, fish to eat, furs to wear and plants to harvest.
Mainstream – the return of the beaver
Beaver Trust’s first programme Mainstream is about making beavers a normal part of our waterscape once again. We encourage farmers, fisheries, foresters, landholders and communities to work together to restore river habitats using beavers.
Beaver wetlands bring benefits
- Clean water – beaver dams and ponds filter out pollutants such as agricultural chemicals.
- Capture carbon – beaver dams hold back silt that locks up carbon, while the huge amount of new plant growth also forms a carbon sink.
- Reduce flooding – beaver dams and pool systems slow the speed of water flowing through the system and prevent flooding downstream.
- Prevent drought – beaver ponds hold water for use in periods of drought.
- Abundant nature – beaver ponds provide nurseries for invertebrates, fish and amphibians; while clearings fill with wild flowers, attracting insects and birds.
Natural water engineering
Beavers are often called “ecosystem engineers”. Think of all the human-made structures that correspond to beaver technology: dams, weirs, locks, canals, even prehistoric houses. As we return to “natural engineering” to help us adapt to climate change, we can learn from these remarkable animals:
- Approved by experts – beavers are such capable ecosystem engineers that they have been proposed as a tool for implementing the EU Water Framework Directive.
- Natural solution – research by the Environment Agency suggests returning England’s waterways to a good ecological condition could generate £21 billion in benefits over 37 years. Beavers could play a part in helping us to achieve this.
- Huge cost savings – beavers know instinctively what to do and they are highly effective. It’s up to us to work out how to live alongside them and make the most of what they can do.
Healthy rivers mean healthy people
Beaver landscapes are special places – they feel truly wild, bursting with birdsong, the buzzing of insects, new plant life and sunlight on water. This is good for nature and good for people too.
- Good for our mental health – by immersing ourselves in the unique landscapes beavers create, we can reconnect with nature, and improve our own health and well-being.
- Living alongside nature – we need to remember how to live better with nature if we are to farm, work and live sustainably in the future. Working with beavers can help us open our minds to a new way of collaborating with wildlife.
- Learning as we go – by collaborating with scientists, we will be able to monitor the hydrological, ecological and sociological impacts of beavers. And we will share this with young people in schools and universities. Our work will be open source and accessible to all.
The science of beavers
We have gathered decades of scientific research from UK, continental Europe and North America to share with people interested in diving deeper into the world beavers.
From beaver biology, ecology and management to their effects on flooding, farming, pollution, carbon, fish and other wildlife, research has been done to help us understand beavers and their wetlands, and to inform how we can co-exist with them.
This list of resources is being constantly amended and updated so check back again soon for more information.
ECOSYSTEM SERVICES
It is well known that beavers engineer ecosystems and in doing so have a range of impacts on ecology, hydrology and geomorphology of aquatic systems, and human society. Prof. Richard Brazier and colleagues from University of Exeter have recently published a very readable overview of these impacts and what they will mean for the future as beavers continue to expand their range throughout the northern hemisphere. A recent paper from the Exeter team looked specifically at how beaver dams attenuate flow by examining records from four sites in Britain with different catchment characteristics (stream orders ranging from 2 to 4; agricultural or forest-dominated). Their findings showed flow attenuation across a range of rainfall conditions with a reduction in average flood flows of up to 60%. Altogether, their data provide compelling evidence that beavers can play a major role in delivering natural flood management in Britain. Full details and access to the papers can be found in the Beavers and land and water section below.
THE ECONOMIC VALUE OF ECOSYSTEM SERVICES
Beavers provide benefits through the ecosystem services (water purification, moderation of extreme events, habitat and biodiversity provision, nutrient cycling, greenhouse gas sequestration, recreational hunting and fishing, water supply, and non-consumptive recreation) they provide but quantifying and putting a common system of values on these services is no mean feat. It’s a complex area and there are estimates for some services in some areas in the literature. However Stella Thompson and her colleagues have gone a step further and estimated the value of beaver benefits from across the Northern Hemisphere; their findings are presented in a paper recently published in Mammal Review (see Beavers, people and management below). The numbers are large, in terms of millions of USD, for each service from across the range of both North American and Eurasian beavers. Such schemes, but maybe based on estimates at local, regional and national scales, could greatly assist in offsetting the costs to landowners and others resulting from beaver impacts by the ecosystem benefits that beavers provide.
BEAVERS ARE NOT A DISEASE RISK
From the time that beavers were first introduced from Europe into various locations in Britain, an understandable concern has been whether they pose any disease or parasite risks to people or native wildlife. A paper published early in 2021 by Roisin Campbell-Palmer and her colleagues largely puts these concerns to rest. They examined live beavers and beaver carcasses from from three areas: Tayside, Knapdale and Devon (with beavers originally coming from either Norway or Germany). They found that all beavers were in good health and did not harbour any non-native disease or parasites of potential concern and generally they revealed low levels of disease and parasite exposure. They conclude that beavers are, “not acting as reservoirs of significant zoonotic disease“. Details and access to the paper can be found in the Beavers health and genetics section below.
SOCIETAL IMPACTS OF BEAVERS
As well as their influence on the ecology, hydrology and geomorphology of rivers, lakes and wetlands, beavers can affect the activities of people who one way or another interact with these aquatics systems. This can lead to benefits such as increased biodiversity, reduced flooding and increased tourism but also to conflict situations which can be especially troubling when beavers move into new areas. With respect to the latter, early engagement with local stakeholders is crucial to minimise conflict escalation, particularly in connection with beaver reintroductions. Roger Auster and colleagues have recently published four papers on these topics based on the River Otter Beaver Trial in Devon, England. This includes a paper on contrasting perspectives about beavers within the angling community and how potential conflicts can be minimised. The go-to handbook for beaver management is by Dr Roisin Campbell-Palmer et al and is full of support for land and river managers based on decades of international experience. Details can be found in the Beavers, people and management section below.
BEAVER DAMAGE TO AGRICULTURAL CROPS
Beavers dams can have unacceptable impacts on farmland by blocking culverts and drains, flooding pasture and arable crops or waterlogging fence-lines and tracks. They may also have direct effects by consuming agricultural crops such as maize but an important question is how significant is this financially. A new paper by Mikulka and colleagues (2020) in an agricultural landscape in the Czech Republic explores this in detail. They quantified consumption for a range of different crops over a two-year period, taking into account beaver numbers, distance of crop from the beavers’ burrow, the month of the growing season and the growth stage of the crops. Although the beavers used all the different crops as a food source at different times, the authors concluded, “From an economic point of view, beavers pose no serious problems to farmers as the numbers in open agricultural landscapes remain low. The total financial loss is extremely low, and it considered negligible in comparison to crop damage from other rodents or game species.” The paper can be found in the Beavers, people and management section below.
SMOKEY THE BEAVER
A recent, topical paper on how beavers create wildfire refuge areas in USA has been published by Emily Fairfax and Andrew Whittle, and Ben Goldfarb has written a popular review of this important work in National Geographic. It is another example of the benefits of wetland habitats and rich riparian corridors created by beavers for both humans and wildlife. The full references to these articles can be found in the Beavers and land and water section below.
Beavers, people and management
Beaver Management Strategy Framework
Authors: River Otter Beaver Trial (ROBT) Management Group Year: 2019 Source: Devon Wildlife Trust
The five-year ROBT finished in March 2020. The Management Strategy Framework document was produced towards the end of 2019 to inform DEFRA on a future strategic management approach that should be adopted for the population of beavers found in the River Otter after the trial ended. The framework will also be of use for the management of beavers in other catchments.
Conflicts over wildlife conservation: Learning from the reintroduction of beavers in Scotland
Authors: Coz, D. M. & Young, J. C. Year: 2020 Source: People and Nature 2(2): 406-419.
This paper examines the social dimension of planned and unplanned beaver reintroductions in Scotland to understand the issue, the potential for, and impact of, conflict between groups or individuals with differing views on beavers and reintroductions.
The Eurasian Beaver Handbook: Ecology and Management of Castor fiber
Authors: Campbell-Palmer, R., Gow, D., Campbell, R., Dickinson, H., Girling, S., Gurnell, J., Halley, D., Jones, S., Lisle, S., Parker, H., Schwab, G. & Rosell, F. . Year: 2016 Source: Exeter: Pelagic Publishing, UK.
This compact handbook tells you all you need to know about the ecology and management options for beavers.
Ecosystem services provided by beavers Castor spp.
Authors: Thompson, S., Vehkaoja, M., Pellikka, J. & Nummi, P. Year: 2020 Source: Mammal Review n/a(n/a).
The authors have estimated the value of ecosystem services provided by beavers across the Northern Hemisphere. Services include: water purification, moderation of extreme events, habitat and biodiversity provision, nutrient cycling, greenhouse gas sequestration, recreational hunting and fishing, water supply, and non-consumptive recreation. Despite the many assumptions that have had to be made in the estimation process, the values are large. The study demonstrates how payments for ecosystem services can be quantified, and points the way forward as to how such value estimates can be used by wildlife and government organisations to offset losses due to beavers incurred by, for example, landowners and fisheries.
Unravelling perceptions of Eurasian beaver reintroduction in Great Britain.
Authors: Auster, R., Puttock, A. & Brazier, R. P. Year: 2020 Source: Area 52: 364-375
The authors investigate the complex social dimensions of wildlife reintroductions and highlight the need to recognise the perceptions of society and how problems might be solved.
Improving engagement in managing reintroduction conflicts: learning from beaver reintroduction
Authors: Auster, R. E., Barr, S. W. & Brazier, R. E. Year: 2020 Source: Journal of Environmental Planning and Management
Based on interviews with people who reported conflicts with beavers in connection with the River Otter Beaver Trial in Devon (2015-2020), this paper considers how best to engage with these people to reduce conflict situations.
Tourism in Reintroduction Projects: Exploring Social and Economic Benefits of Beaver in Local Settings
Authors: Auster, R. E., Barr, S. W. & Brazier, R. E. Year: 2020 Source: Journal for Nature Conservation 125920
One of the potential benefits of wildlife reintroduction projects is an increase in tourism with economic benefits to local businesses. The authors explore the many aspects of this with particular reference to the River Otter Beaver Trial In Devon (2015-2020).
European beaver (Castor fiber) in open agricultural landscapes: crop grazing and the potential for economic damage
Authors: Mikulka, O., Homolka, M., Drimaj, J. & Kamler, J. Year: 2020 Source: European Journal of Wildlife Research 66(6): 101.
This paper examines the financial impact of crop grazing by beavers in an agricultural landscape in the Czech Republic.
Alternative perspectives of the angling community on Eurasian beaver (Castor fiber) reintroduction in the River Otter Beaver Trial
Authors: Auster, R.E., Barr, S. & Brazier, R. Year: 2020 Source: Journal of Environmental Planning and Management
This paper examines beaver-angler relationships and identifies three contrasting perspectives that exist amongst the angling community in the catchment of a trial beaver reintroduction on the River Otter in Devon. England. The paper goes on to discuss ways in which potential conflict can be minimised.
Beavers and wildlife
The impacts of beavers Castor spp. on biodiversity and the ecological basis for their reintroduction to Scotland, UK
Authors: Stringer, A.P. & Gaywood, M.J. Year: 2016 Source : Mammal Review: 46(4): 270-283.
This review investigates the mechanisms by which beavers act as ecosystem engineers, and discusses the possible impacts of beavers on the biodiversity of Scotland.
Rewilding wetlands: beaver as agents of within-habitat heterogeneity and the responses of contrasting biota
Authors: Wilby, N. J., Law, A., Levanoni, O., Foster, G. & Ecke, F. Year: 2018 Source : Philosophical Transactions of the Royal Society B: Biological Sciences 373(1761)
Plants and beetles, as examples of different functional groups, were surveyed in beaver ponds and coexisting ‘other’ wetlands in Sweden. The results demonstrated that beavers should benefit aquatic biodiversity across different scales.
Qualitative and quantitative effects of reintroduced beavers on stream fish
Authors: Kemp, P. S., Worthington, T. A., Langford, T. E. L., Tree, A. R. J. & Gaywood, M. J. Year: 2012 Source: Fish and Fisheries 13(2): 158-181.
This paper presents a systematic review of the impacts of beaver dams on fish and fish habitat based on the literature and expert opinion.
Ecology and movement of juvenile salmonids in beaver-influenced and beaver-free tributaries in the Trøndelag province of Norway
Authors: Malison, Rachel L. & Halley, Duncan J. Year: 2020 Source: Ecology of Freshwater Fish n/a: n/a
This paper looks at how beaver dams affected habitat, food resources, growth and movement of juvenile Atlantic salmon and trout. The authors found that dams dams did not block the movement of juvenile salmonids or their ability to use upstream habitats. It appears that it is unlikely that dams negatively affect the juvenile stage of salmon or trout populations.
A review of the influence of beaver Castor fiber on amphibian assemblages in the floodplains of European temperate streams and rivers
Authors: Dalbeck, Lutz, Hachtel, Monika & Campbell-Palmer, Róisín Year: 2020 Source: The Herpetological Journal 30(3): 135-146.
Based on a literature review, the authors have assessed the effects of beaver dams on amphibians (19 species) in streams across Europe. One of their key findings is that beavers are particularly important for amphibians in headwater streams. These streams constitute more than two-thirds of water bodies in temperate European catchments. They propose that by creating habitat for endangered European amphibian species, beavers contribute to their long-term conservation.
Beaver dams are associated with enhanced amphibian diversity via lengthened hydroperiods and increased representation of slow-developing species
Authors: Romansic, J. M., Nelson, N. L., Moffett, K. B. & Piovia-Scott, J. Year: 2020 Source: Freshwater Biology
The authors looked at the relationship between beavers and pond-breeding amphibians, particularly slow developing species, at a site in Washington state in North America. Ponds behind dams were found to greatly benefit amphibians especially slow-developers and variable-rate developers, and could be particularly effective in the future as climate warming reduces water levels during the summer.
Beaver health and genetics
Reintroducing beavers Castor fiber to Britain: a disease risk analysis
Authors: Girling, S. J., Naylor, A., Fraser, M. & Campbell-Palmer, R. Year: 2019 Source: Mammal Review 49(4): 300-323.
This paper carries out a disease risk analysis, based on peer reviewed publications, for selection and health screening of Eurasian beavers prior to release into the wild in Britain.
Evidence of Leptospira species and their significance during reintroduction of Eurasian beavers (Castor fiber) to Great Britain
Authors: Girling, S. J., Goodman, G., Burr, P., Pizzi, R., Naylor, A., Cole, G., Brown, D., Fraser, M., Rosell, F. N., Schwab, G., Elliott, M. & Campbell-Palmer, R. Year: 2019 Source: Veterinary Record 185(15): 482
Beavers reintroduced to Britain were screened for Leptospira species. Levels of infection were found to be low and did not appear to cause significant morbidity or mortality.
Identifying source populations for the reintroduction of the Eurasian beaver, Castor fiber L. 1758, into Britain: evidence from ancient DNA
Authors: Marr, M. M., Brace, S., Schreve, D. C. & Barnes, I. Year: 2018 Source: Scientific Reports 8(1): 2708.
If the translocation of wild beavers to establish new populations is being considered, where are the most suitable source populations? This study uses DNA analysis and radiocarbon dating on the ancient British beaver population to help understand the most appropriate source populations for the reintroduction of beavers into Britain.
Nuclear and mitochondrial genetic structure in the Eurasian beaver (Castor fiber) – implications for future reintroductions.
Authors: Senn, H., Ogden, R., Frosch, C., Syrůčková, A., Campbell-Palmer, R., Munclinger, P., Durka, W., Kraus, R. H. S., Saveljev, A. P., Nowak, C., Stubbe, A., Stubbe, M., Michaux, J., Lavrov, V., Samiya, R., Ulevicius, A. & Rosell, F. Year: 2014 Source: Evolutionary Applications 7(6): 645-662.
This paper considers the genetics of beavers when selecting animals for reintroduction and the risks of low genetic diversity, inbreeding depression and outbreeding depression.
Eurasian beaver (Castor fiber) health surveillance in Britain: Assessing a disjunctive reintroduced population
Authors: Campbell-Palmer, R., Rosell, F., Naylor, A., Cole, G., Mota, S., Brown, D., Fraser, M., Pizzi, R., Elliott, M., Wilson, K., Gaywood, M. & Girling, S. Year: 2021 Source: Veterinary Record
This paper looks at the health and condition of beavers (based on live animals and dead specimens) from three locations in Britain (Tayside and Knapdale in Scotland, and Devon in England ) and considers whether they pose a disease risk. They found all the beavers to be in good condition, did not harbour non-native parasites or disease of potential concern and are not acting as reservoirs of significant zoonotic disease.
Beavers and land and water
Modelling Eurasian beaver foraging habitat and dam suitability, for predicting the location and number of dams throughout catchments in Great Britain
Authors: Graham, H. A., Puttock, A., Macfarlane, W. W., Wheaton, J. M., Gilbert, J. T., Campbell-Palmer, R., Elliott, M., Gaywood, M. J., Anderson, K. & Brazier, R. E Year: 2020 Source: European Journal of Wildlife Research 66(3): 42.
Models can be helpful for understanding the suitability of habitats for species and future changes in a population over time. Here the authors have developed models to predict the distribution of beaver foraging habitat and dams within European landscape to support reintroduction policy and management.
The role of Eurasian beaver (Castor fiber) in the storage, emission and deposition of carbon in lakes and rivers of the River Ob flood plain, western Siberia
Authors: Cazzolla Gatti, R., Callaghan, T. V., Rozhkova-Timina, I., Dudko, A., Lim, A., Vorobyev, S. N., Kirpotin, S. N. & Pokrovsky, O. S. Year: 2018 Source: Science of The Total Environment 644: 1371-1379.
Nutrient recycling and carbon sequestration as a result of the activity of beavers are considered here i relation to river management and the conservation and management of beavers.
River Otter Beaver Trial: Science and Evidence Report.
Authors: Brazier, R., Elliot, M., Andison, E., Auster, R., Bridgewater, S., Burgess, P., Chant, J., Graham, H. A., Knott, E., Puttock, A., Sansum, P. & Vowles, A. Year: 2020 Source: Devon Wildlife Trust
The five year trial reintroduction of beavers to the River Otter in Devon started in 2015 and ends this year. A detailed research programme was carried out throughout the trial and this beautifully illustrated report summarises the findings.
Managing for large wood and beaver dams in stream corridors
Authors: Wohl, E., Scott, D. N. & Yochum, S. E. Year: 2020 Source: Gen. Tech. Rep. 404. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.
This is a comprehensive literature review concerning large wood in rivers and beaver dams. It discusses their costs and benefits and presents guidelines for identifying stream sections that maximize the potential environmental benefits associated with logjams and beaver dams, while minimizing possible hazards. Although the review primarily refers to North American beavers and landscapes, it includes extensive reference to work carried out in Britain, Europe and elsewhere.
Beaver: Nature’s ecosystem engineers.
Authors: Brazier, R. E., Puttock, A., Graham, H. A., Auster, R. E., Davies, K. H. & Brown, C. M. L. Year: 2020
The engineering attributes of beavers and their impacts on ecology, hydrology and geomorphology of aquatics systems, and their relationship with human society, are reviewed, and what the future holds considered as beavers continue to establish themselves throughout the northern hemisphere.
Beaver dams attenuate flow: A multi-site study
Authors: Puttock, A., Graham, H. A., Ashe, J., Luscombe, D. J. & Brazier, R. E. : Year 2021 Source: Hydrological Processes
The authors explore the flow characteristics of rivers under a variety of rainfall events after the building of dams by beavers at four locations in Britain, each with different catchment characteristics. Their findings show how beaver dams can attenuate average flood flows by up to ca. 60%, and overall beavers could play a critically important part in natural flood management.
Population and distribution of beavers
Population and distribution of beavers Castor fiber and Castor canadensis in Eurasia
Authors: Halley, D. J., Saveljev, A. P. & Rosell, F. Year: 2020 Source: Mammal Review n/a(n/a).
This timely paper reviews the current distribution of Eurasian beavers in Eurasia and the introduced North American beaver in Finland and north-west Russia. Beavers are continuing to colonise new areas, including densely population and low-lying areas across the region. The authors warm that beaver management strategies need to be in place in these landscapes before beaver densities increase to a point where negative impacts will occur.
Population of Eurasian beaver (Castor fiber) in Europe
Author: Wróbel, M. Year: 2020 Source: Global Ecology and Conservation 23: e01046
The author updates information about the number of beavers in different European countries.
Books about beavers
The Eurasian Beaver By Roisin Campbell-Palmer et al. (2015)
Authors: Campbell-Palmer, R., Gow, D., Needham, R., Jones, S. & Rosell, F. Year 2015:
Publishers: Pelagic Publishing, Exeter, UK.
Beavers in Britain’s Past by Bryony Coles (2006)
Author: Coles, B. Year: 2006
Publishers: Oxbow Books, Oxford UK.
Nature‘s Architect: The Beaver’s Return to Our Wild Landscapes by Jim Crumley (2015)
Author: Crumley, J.. Year: 2015
Publishers: Saraband, Glasgow, UK.
Beavers (British Natural History Series) by Andrew Kitchener (2001)
Author: Kitchener, A. Year: 2001
Publishers: Whittet Books Ltd., Stowmarket, UK.
Eager: The Surprising, Secret Life of Beavers and Why They Matter by Ben Goldfarb (2019)
Author: Goldfarb, B. Year: 2019
Publishers: Chelsea Green Publishing Co., White River Junction USA.
Bringing Back the Beaver: The Story of One Man‘s Quest to Rewild Britain’s Waterways by Derek Gow (2020)
Author: Gow, D. Year: 2020 Due out in Sepetember.
Publishers: Chelsea Green Publishing Co., White River Junction USA.
The Beaver: Its Life and Impact, Second Edition by Dietland Müller-Schwarz (2011)
Author: Müller-Schwarz, D. Year: 2011
Publishers: Cornell University Press, New York, USA.
