Aspiration for a beaver recovery network
For hundreds of years, the furry, paddle-tailed figure of the Eurasian beaver has been missing from the rivers of the UK
Once widespread, beavers were hunted to extinction for their fur, meat and scent-glands (used for making perfume). The last wild British beaver died in Scotland in the 16th century. The loss of this charismatic species also led to loss of the mosaic of lakes, meres, mires, tarns and boggy places that it so brilliantly built.
Beavers are a keystone species which means that they play a crucial role in how an ecosystem functions. By building dams, digging ditches and coppicing trees, beavers can alter their surroundings in a big way, creating large areas of wetland, slowing the flow of streams and rivers, protecting the land downriver from flooding and improving water quality. These restored wetlands also provide essential habitat for a wealth of plants and other animals such as otters and water voles.
What is a beaver
The Eurasian beaver is a large herbivore that was formerly native to these shores and once played an important part in our landscape.
They are nocturnal for much of the year, but during the light summer evenings they can be seen during daylight hours.
Beavers make dams so that they can move about and feed in safety. They like the entrance to their burrow to be submerged, so where they don’t have deep water, they can create it. In larger rivers and lakes, they don’t need to build dams.
The work they do, coppicing trees and building dams, creates wetland habitats that benefit an enormous number of other species from water voles to amphibians, dragonflies to birds.
Myth busting facts about beavers
Beavers are vegetarians. They do not eat fish. In fact, they are known to co-exist well with them, boosting fish populations. Beavers snack on riverside plants, grasses, as well as tree bark and shoots.
Beavers feel safest in still, deep water (around 70cm). They are very unlikely to stray far from it and will create dams if the water levels aren’t what they would like them to be.
Beaver dams vary in size and structure. In many cases they are small temporary structures made of twigs, which gradually break down as water levels rise. In others, they can be larger stable structures that create big ponds. Both water and fish are able to move through and around them and they are not the huge dam structures made by the North American beaver.
Beavers can improve water quality by impounding water behind their dams and diffusing pollutants being transported downstream. Their dams act as sediment traps cleaning our waters.
This isn't just about the reintroduction of a species - it's about the reintroduction of an entire ecosystem that's been lost.
The Isle of Wight beaver recovery project
Hampshire & Isle of Wight Wildlife Trust hope to return the beaver to the Isle of Wight. The Trust has a strong track record of working to bring back missing species, and have already seen otter, water vole and marsh fritillary return to their former haunts.
This project is a key part of the Trust’s Wilder Wight vision and one that we hope can support transformative change in the face of a climate and ecological emergency.
It is the Trust’s aspiration that any forthcoming release strategy would lead to a long term free living population of beaver on the Isle of Wight.
The beaver recovery project would aim to achieve multiple outcomes:
- Wildlife would be enhanced through the creation of a broad range of habitats, ranging from dam and pool complexes in the floodplain, to the provision of more standing and fallen dead wood features.
- Sustainable water purification, natural flood protection and silt capture.
- Accessible public engagement with the species, education opportunities and ecotourism ventures.
- An increased understanding of population dynamics and the landscape utilisation of wild beaver populations across a lowland, river catchment which has been previously dominated by agriculture and other highly modified land uses.
Beavers will support the Island as an emerging leading destination for the enjoyment of nature
The Isle of Wight has the potential to become a leader in nature recovery networks within the south of England, helping to put nature back in charge of its own recovery and addressing the impacts of climate change.
A thriving nature based economy is part of the Trust’s vision, and it is our expectation that the recovery of beaver to the Island will act as a notable catalyst.
What have we done so far
In 2020 the Trust commissioned a report and field survey by Dr Róisín Campbell-Palmer, Derek Gow, Prof Richard Brazier and Dr Alan Puttock.
The study assessed the habitat suitability for beaver on the Isle of Wight and provided a feasibility for release scenarios.
Particular emphasis was given to the Eastern Yar catchment, where a large proportion of Trust land occupies the river corridor, such as at Newchurch Moors Nature Reserve.
The report determined:
That some riparian environments on the Isle of Wight afford entirely suitable beaver habitat while in tandem others would provide for successful long-term colonisation. The high degree of suitability would influence the recommended release strategy, which could be implemented in three ways:
- Reserve release – fenced
- Reserve release unfenced and Eastern Yar release with permitted natural spread
- Wild release for entire Isle of Wight
All scenarios could be successfully implemented in conjunction with well adopted beaver management strategies.
Existing collaborative partnership conservation and land-management projects on the Island already recognise and promote objectives such as managing scrub woodland, habitat connectivity, promotion of sustainable tourism, developing high value green spaces, woodland replanting and flood prevention. These activities all readily lend themselves to beaver reintroduction.
The Trust has secured funding to take the project to the next phase of feasibility, consultation and engagement.
This would shape a potential license application to Natural England to release beavers within the framework of a specified release strategy.
In Spring 2021 a Project Officer will be appointed to lead this work with an event programme published shortly afterwards.
Hampshire & Isle of Wight Wildlife Trust have also been contributing to a national Wildlife Trust working group, representative of many Wildlife Trusts, with both existing and pending beaver projects. Part of the purpose of this group is to:
- Inform national-level engagement with government to clarify the legal status of beaver.
- To adopt a national beaver management framework.
- To explore ways of incentivising beaver presence and management within the new Environmental Land Management Scheme (ELMS).
The Beaver Trust has also been a close consultee of the Trust’s emerging plans and we are grateful for the support and advice provided to date.
Why the Eastern Yar?
The Isle of Wight is a popular tourist destination with numerous recreational outdoor activities such as water sports, walking, seaside activities, fishing and horse riding all being important to the island’s economy. Rights of way and open access land proliferate in the wider landscape. As England’s largest island, completely separated from the mainland by the Solent, the Isle of Wight represents a unique opportunity to investigate beaver reintroduction at a catchment level.
The Eastern Yar is the largest river on the Island (24km) and is classed as being of moderate ecological quality. The catchment is typically lined by low willow scrub and interconnected by numerous drainage channels, floodplain grasslands and reedbed, much of which is owned or occupying by conservation organisations, notably Hampshire & Isle of Wight Wildlife Trust. We own 300 acres of linked land in the catchment that spans 4.5km of the river channel and consists of prime habitat suitable for a beaver release.
While the ground water quality is classed as good, high levels of nitrogen and pesticide pollution can be an issue by the time the outflows reach the Solent, partly exacerbated by past modification to the river through built impoundments, dredging and drainage of the floodplain.
Newchurch Moors Nature Reserve was deemed to provide exceptionally good habitat for beaver. Within the reserve are a series of interconnecting freshwater ponds, heavily lined by woody vegetation including shrubby willow and range of mature tree species. These ponds also possess a good coverage and range of semi-emergent and aquatic plant species. All of which would provide beavers with rich, year-round forage, presenting a highly suitable release location.
With excellent resources for foraging and shelter creation, beavers could be readily released directly into the Eastern Yar where they might be expected to flourish. The long-term goal of this prospect would be to create a best practice example to promote both positive habitat restoration through beaver activity and to ensure a targeted approach to the selection of founder stock sufficient to maximise complete genetic diversity.
Why are beavers important?
Beavers should be an integral part of a green recovery
Wetlands are some of the most important habitats for supporting wildlife, and as such, their restoration is crucial to the restoration of a healthy living landscape.
Beavers create thriving ecosystems helping us to put nature firmly back on the road to recovery. The wetlands and pools they create capture carbon, locked up in boggy vegetation, helping to tackle climate change impacts by reducing flood risk downstream and keeping streams and rivers running during droughts. And they do all this for free!
Beavers are 'ecosystem engineers'
They make changes to their habitats, such as digging canal systems, damming water courses, and coppicing tree and shrub species, which create diverse wetlands. In turn these wetlands can bring enormous benefits to other species, such as otters, water shrews, water voles, birds, invertebrates (especially dragonflies) and breeding fish.
They also help to reduce downstream flooding - the channels, dams and wetland habitats that beavers create hold back water and release it more slowly after heavy rain.
Beaver dams also slow and filter water, causing sediment and nutrients to be deposited in ponds. This improves the quality of water flowing from sites where beavers are present.
Beavers can provide a nature-based solution
Beaver wetlands capture carbon, locked up in dams, and boggy vegetation and wet woodlands which are restored.
Beavers can also offer a nature-based solution to improving the health and function of river catchments. The beaver-created wetlands can act as sponges which can capture organic sediments, and reduce the effects of agricultural runoff and harmful chemicals such as pesticides, which in turn helps to improve water quality downstream.
Evidence reveals benefits from beavers
The impressive and ever-growing body of independent scientific evidence reveals the vast array of benefits that beavers can bring to society by working with nature.
Multiple trials, including the Scottish Beaver Trial and the River Otter Beaver Trial show huge improvements to wildlife, water quality, flood reduction, sediment reduction and more where beavers are re-introduced.
Frequently asked Questions
What is a keystone species?
A keystone species is a species which plays a unique and critical role in the way an ecosystem functions, or in the structure and health of a habitat. The presence of keystone species determines the types and numbers of other species found in that environment. Without keystone species, the habitat is dramatically different, usually far less healthy, and in many cases, ceases to exist. An analogy is the keystone in a brick arch. If you remove the keystone then the arch collapses. When beavers were removed from Britain, the habitats they supported collapsed.
Do beavers cause environmental damage?
Beavers do modify the habitats and landscapes they live in through coppicing, feeding and in some cases damming (beavers living on lakes or large rivers have little need of constructing dams). In the first instance, these changes can markedly alter the appearance of the local environment but these modifications mostly have a positive effect on biodiversity.
Beaver adaptations can bring enormous benefits to other species, including otters, water shrews, water voles, birds, invertebrates especially dragonflies, and breeding fish. In effect, beavers naturally create and maintain diverse habitats. Their dams can hold water in periods of drought, can regulate flooding and improve water quality by holding silt behind dams or onto the floodplain. They also provide an important role by intercepting acidic and agricultural run-off.
Beavers forage close to water with activity usually concentrated within 20m of the water’s edge. Beavers do fell broad-leafed trees and bushes in order to eat the bark during the winter and to construct their lodges. Most trees will be coppiced and will regenerate, which diversifies the surrounding habitat structure. Coppicing has been practiced by foresters throughout history as a method to manage bankside trees. The actions of beavers are very similar meaning the woodlands will be naturally maintained.
Beavers are a species that occasionally require the need for direct management intervention, if their activities result in undesirable localised flooding or tree felling. Any occasional problems are usually overcome by simple actions, such as overflow piping and electric fencing. In rarer instances beaver dam activity can be cleared, often forcing the beaver to move on.
Do beavers cause damage to farmland and the wider countryside?
Evidence from Europe and elsewhere in the UK shows that beaver damage is, in the vast majority of cases, small-scale and localised. The presence of beavers across large parts of Europe has become more common place, including in farmed landscapes and more urban environments. Where beavers are considered a problem it is usually treated as a manageable issue with many effective techniques available. These include the removal of dams, the introduction of overflow piping, tree protection or the installation of fencing (as one does for deer and rabbits).
Do beavers pose a flooding threat?
Beavers rarely build dams in main rivers downstream where there is sufficient depth of water, and so many of the concerns about flooding are unfounded. However, in low lying floodplains where agricultural activities depend on land drains and deep ditches, beaver dams can have more significant impacts. They can obstruct culverts and “restore wetlands” in places that are not compatible with the existing land-uses and therefore create real, and perceived conflicts. In some cases mitigation measures will not be successful, and beavers may need to be moved on.
Evidence from elsewhere in Europe shows that instances of beaver dams creating undesirable flooding are uncommon, localised and usually small-scale. In these situations dams are simply removed or pipes (‘beaver deceivers’) are placed through them to manage water levels.
Beavers can make rivers less prone to flash floods, reducing flooding by holding water in ‘the right place’ in river headwaters, and enabling the slower release of water in drier periods.
A project with the University of Exeter in the River Otter has studied the impacts of beavers on water flows and hydrology in great detail. The results are remarkable and show that beavers tend to decrease flooding overall.
It is important to differentiate between the storage of water by beavers in river headwaters, and the impact of beavers on low lying land. In some places, culverts and drainage systems, some of which are critical to reducing flood risk, need to be kept clear of beaver debris.
In order to create habitat for themselves, and to store water upstream, beavers need to temporarily and seasonally flood areas of land to create beaver ponds. This can be managed so that they do this in areas where flooding is wanted.
Are Beavers native?
Beavers are a native species to Britain and were lost from our wetlands a few hundred years ago. They were hunted to extinction for their fur, meat and castoreum. Many places derive their names from the presence or influence of beaver activity on the local areas. We have perhaps lost the recent cultural memory and association from living among these animals but many river catchments today still exhibit signs of beaver activity from hundreds of years prior.
In Hampshire fossil evidence has been discovered on the Test & Itchen catchments ranging from Bronze Age to Medieval eras. Evidence is limited for the Isle of Wight but this should not be deemed as evidence of absence. The locality of the island to the mainland coupled with the once extensive floodplain wetlands that would have been prevalent, makes it likely that beavers would have been present. Furthermore, the beaver’s appeal to early human settlers and the island’s isolation would have made them susceptible to early extinction, relative to their mainland counterparts. The impact of early human arrival relating to the demise and extinction of many species has been well documented.
The economic impacts of beavers
A study on the economic impacts of the beaver by the University of Oxford's Wildlife Conservation Research Unit concluded that "with forethought, prior consultation and planning, a beaver reintroduction should bring significant monetary benefits within the local economy and communities that could greatly outweigh any potential negative impacts.”
Research into the impact of beavers on the local economy around Knapdale Forest was carried out as part of the Scottish Beaver Trial and its results are currently being assessed by the Scottish Government. Local businesses reported an upturn in business due to interest in the Trial increasing visitor numbers to the area. There is also increasing evidence of growing beaver tourism to the River Otter in Devon.
Do Beavers eat fish?
Beavers are entirely vegetarian (herbivorous) and don’t eat fish. Their presence is generally very positive for most fish species. The natural wetland habitats that beavers create often help to increase natural fish populations.
Concern is expressed by some, about the ability of salmon and sea trout to get over dams. The science is stark in demonstrating that long term benefits generally outweigh any localised short term impacts.
Natural woody material is a natural part of river systems and fish have migrated through these natural obstructions for millennia. Woody debris also provides essential cover for for fish of all sizes, as well as providing a ctitical habitat for invertebrates, which in turn provide prey for fish. Man-made obstructions to fish passage have a far greater impact on migrating fish populations.
What do Beavers eat?
Beaver are entirely herbivorous, eating only plants and woody material. Not just trees but they’ll be eating brambles and other plants too. They’re big fans of Himalayan balsam, which is an invasive non-native species that can spread easily and become problematic for our native wildflowers.
In summer, beavers graze mostly on riverside plants and grasses. In winter they feed mostly on tree bark and shoots. They like to eat willow and aspen trees, and to a lesser extent, alder. They will take fruit trees (particularly apple) and poplar trees if these are close to watercourses. If required, these tress can be effectively protected.
Beavers tend not to move far from fresh water so impacts are often very close to the riverbank, generally within 20m.
Do Beavers prefer certain tree species?
Beavers coppice trees to create dams. Many of the trees beavers cut for damming, are species like willow which will grow and re-root where they are ‘planted’ by the beaver.
Beavers have a definite preference for certain trees. Preferred tree species include alder, aspen, apple, birch, cherry, cottonwood, poplar and willow. Aspen/poplar and apple are their favourite. If the supply of their preferred trees is low they will harvest oaks and some maples. Conifers such as pines, hemlocks, etc. are their least favourite.
Most native trees will naturally re-sprout when cut (coppicing). However, browsing by deer and livestock has a far more detrimental impact on regrowth. Special trees can easily be protected from beaver activity.
Will we lose trees, and do Beavers cut more at certain times of year?
Beavers are often known as eco-engineers, they are only doing what our team of reserve officers would be doing on our wetland reserves to provide the best habitat for wildlife, but they will be doing it far better than we can!
There tends to be a large initial cut when beavers first arrive in their new enclosure, which can be alarming for some people to see. As beavers settle in for the first few months you may notice trees being cut as they build shelters and dams. Most of this is coppicing, so they will grow back and provide more spaces for wildlife. Tree coppicing can look bare in winter, but that it will promote lush regrowth in the spring – a way of beavers helping to regenerate their own food supply.
You may notice that beavers cut down more trees in late autumn. This is because they are stockpiling a food cache of sticks for the winter.
How far from water do Beavers cut trees?
Beavers are well adapted to water and evolved over millennia to use water as a defence from predators. While surprisingly fast over short distances, beavers do not like to travel too far from the water to cut down a tree, and most of the trees that beavers cut down are within 30 metres of the water.
As beavers deplete the supply of food trees close to the pond’s edge they may raise the height of the beaver dam to bring the pond closer to more distant trees, or create a series of further dams to access other areas for foraging.
Another engineering method beavers employ is to excavate canals from the pond in the direction of the trees they wish to harvest. Once a tree is toppled they are able to cut off and transport the branches easier and more safely to the pond using their canal.
Will they build dams?
On main rivers or where there is adequate depth beavers do not typically build dams. Beavers tend to build dams to create lagoons in which they can better protect themselves from predators and in which they often build their family lodges which are accessed from underwater. The ideal depth of water a beaver seems to seek behind these dams is around 70cm (28”).
Will there be any adverse effects on wading birds or other species?
Beavers create a mosaic of habitats, from small and large ponds, canals, vegetated margins, wet meadows and areas of mud and silt trapped behind dams. They are ecosystem engineers, and experts in wetland management, creating more diverse habitat for inhabitants, from the smallest invertebrates to large mammals. Evidence from across their European range is compelling in that beaver habitats are not only rich environments, but also support an array of rarer species.
Do beavers affect fish species?
Beavers are herbivorous, so do not eat fish. Habitat modification by beavers, however, can have impacts on fish populations in some circumstances, and fisheries groups are often concerned about the potential impact of beaver dams on the movement of migratory fish. Beaver dams range from temporary to more permanent and influence conditions around them in a variety of ways. Typically beaver dams will create diverse bypass features enabling passage around the structures in many cases. Where beavers are deemed to be problematic management can be put in place to address the issue.
Beaver activities may have both positive and negative impacts on different fish species, although migratory salmon and sea trout cause most concern. Beaver dams may act as barriers to migratory species in some years and cause localised siltation upstream of dams affecting spawning habitat. Understanding the overall impact is complex and it could be argued that further scientific assessment is required from an England context to quantify this effect. On the other hand, positive impacts may include an increase in habitat for fish rearing and overwintering, an increase in refuge areas during high and low flow periods and an increase in aquatic invertebrate prey species. The balance of scientific literature weighs in favour of the benefits overall.
Are the Beavers captive or wild?
Our aspiration is that the proposal for the Isle of Wight would support an open, wild beaver introduction. The details of this will be determined as the project progresses. The implementation plan might require a phase approach, inclusive of enclosed release for time period.
Where will the beavers come from?
This is yet to be determined. Most projects in England source their beavers from Scotland.
Do Beavers carry diseases such as Bovine Tuberculosis?
Any beavers released are health checked by vetenerians to make sure that they do not carry any infectious parasites or diseases, and that they are fit for release both from a disease and a welfare perspective. This process is thorough and adhering to strict conditions required as part of any translocation programme.
There is no evidence from Europe to suggest that Eurasian beavers carry bovine tuberculosis bTB. As most mammals can be infected by bTB it is theoretically possible for beavers to become infected if they are exposed in English landscapes. The risk is thought to be low.
How quickly do beavers breed?
Beavers only breed at 2-3 years old, they breed once a year, and have an average of 3 kits. The kits are vulnerable to predation by foxes, birds of prey and maybe otters – so not all kits survive.
When first released, adult beavers initially colonise relatively rapidly over large distances. Once territories are established, population numbers only rise slowly. Beavers live in strict family groups, with only the dominant pair breeding.
Beaver numbers and the resources available to them will be monitored throughout the project to ensure animal welfare. If the territories become saturated, we may need to re-home older offspring several years down the line.
Will we be able to see the beavers?
Beavers live in burrows dug into river and pond banks. They also live in lodges built out of sticks and mud, which can be seen above ground. They are mostly nocturnal (they are active at night). They can be seen emerging or returning to their lodges at dusk and dawn, times when they are actively feeding, grooming and patrolling their territories.