Frequently asked questions

1. Are Beavers native?

  • Beavers are a native species to Britain and were lost from our wetlands a few hundred years ago
  • Eurasian Beavers (Castor fiber) are found across Europe and much of Asia
  • They were hunted to extinction for their fur, meat and castoreum
  • We recognise a native species as one that recolonised Britain as the ice retreated at the end of the last ice age
  • The beavers for the Knepp and Valewood projects were sourced from UK born beavers. Knepp beavers were sourced from Scotland, and Valewood beavers were sourced from Devon
  • There is archaeological evidence of beaver presence in Sussex
  • There is also a Canadian species of beaver, these are not native to Britain and are not the species that we will be re-introducing

2. Why Beavers?  

  • Beavers are a “keystone species” which play an important role in restoring British wetland ecosystems. They naturally create resilient networks of prime wetland habitat, which in turn produces natural capital benefits such as flood relief and benefit a wide range of species including amphibians, fish and bats.
  • Beavers naturally engineer watercourses to create deeper water so they can escape from predators and explore their territories. Where there is no existing deep water, they will create pools using small dams.
  • 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.
  • There are habitats specifically created by beavers that are lacking in Britain, including beaver meadows, beaver dams and flooded wet woodland.
  • Beavers can play a key role in increasing woodland, wetland, open water and riparian vegetation and wildlife diversity
  • Estimates suggest that at least 80% of our wetlands in Sussex have been destroyed, and much of the remaining 20% is heavily damaged and / or managed.
  • 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.
  • In a 2.8 hectare enclosure in the Devon Beaver Trial , in 7 years, beavers : -  
    • Created 650 m² of open water
    • Increased water storage from 50 m³ to 1000 m³
    • Reduced the flood peak by 30%
    • Increased the time for floods to flow through the site from 15 mins to 1 hr
    • Enhanced the summer baseflow (mitigating drought)
    • Had 3 x less sediment leaving the site than entering it
    • Trapped 70 kg per m² of sediment - of which 70% entered the site as run off from just a 20 ha piece of land upstream.
    • Had 5x less Phosphate pollution leaving the site
    • Increased frogspawn clumps from <20 to >600
    • Stored around 15 tonnes of carbon in 13 ponds
    • There are habitats specifically created by beavers that are lacking in Britain, including beaver meadows, beaver dams and flooded wet woodland
  • Beavers can play a key role in increasing woodland, wetland, open water and riparian vegetation and wildlife diversity
  • Estimates suggest that at least 80% of our wetlands in Sussex have been destroyed, and much of the remaining 20% is heavily damaged and / or managed. 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

3. 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.

4. Do Beavers cause flooding?

  • 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 preliminary 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.
  • There will be low lying agricultural or developed areas in floodplains where beavers may need to be actively discouraged from causing flooding.
  • In the event of an emergency relating to flooding, please contact the EA 24hr Floodline 0845 988 1188. Any emergency relating roads or other highways, call 0845 155 1004 or 0345 155 1004.

5. Are the Beavers captive or wild? 

  • The beavers at Knepp will live in a 240 hectare + enclosure, with the river exits and entrances fenced off so that the beavers can’t escape into the wider catchment. The beavers are effectively captive but living as naturally as possible in an enclosure which has the capacity to support numerous beaver territories
  • The Knepp estate is an ideal location for the trial as it was previously a farmed landscape, both poor for wildlife and for farming, which is now being re-wilded. There is plenty of suitable habitat for the beavers, and the site is remote enough from people and infrastructure that we can observe the beavers impacts on the wider river system, before assessing whether/where it is appropriate to release them into the wider catchment / wider Sussex
  • The Valewood beavers are captive, and will be in a fenced enclosure of 15 ha
  • We don’t envisage that any beavers will be encouraged in the wider river catchment for at least 5-10 years, when our resident populations have had time to breed and fill up the existing enclosures
  • Landowners and neighbours in both catchments have been consulted about the beavers
  • There is a small chance the beavers may escape from the enclosures (i.e. during a storm), but risk assessments have been carried out for this, and mitigation measures put in place

6. Where are the Beavers living? 

  • The beavers will live on a quiet sub-catchment of the Adur river on the Knepp estate, and a headstream of the River Wey at Valewood
  • There is a good network of public footpaths in the main areas where the beavers are currently living, including observation platforms which can be used to look over the beaver occupied areas

7. How should we behave around Beavers?

  • Beavers are nocturnal. If you know you are near a beaver territory during the day, please stay as quiet as possible and behave as unobtrusively as possible
  • Please respect the landowners and avoid disturbance to the beavers by sticking to public footpaths and by following the Country Code
  • Please keep dogs on leads. Although beavers are not aggressive, if attacked by a dog in their territory, particularly if they have young, they will fight back – and they have big teeth!
  • We are keen to provide some sanctuaries where the beavers can live undisturbed where there are no footpaths, so please avoid trespassing

8. Do Beavers carry diseases such as Bovine Tuberculosis

  • The beavers released to Sussex are health checked 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. 
  • The introduced beavers were all healthy and free of any significant diseases, including the tapeworm Echinococcus and bTB. 
  • 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. Scotland – where the Knepp beavers are being sourced from – is currently bTB free. DEFRA has agreed that Scottish beavers therefore do not need to be tested for bTB.

9.  How will we be ensuring the health and welfare of the beavers?

  • Beavers will be sourced from wild living populations - UK born animals from Scotland & Devon
  • All trapping, translocation and screening processes are undertaken by a team of experts, including wildlife vets
  • The project partners include beaver experts from Devon and Scotland who are advising us on how to ensure the beavers are all healthy
  • We have provided professional vets with details of beaver healthcare, and these vets can be called in in case of concerns for beaver welfare
  • Key local stakeholders have been trained in beaver welfare and handling
  • If necessary we will limit human access to key beaver sites to avoid distress to the animals, particularly when breeding
  • The beavers that we are translocating to Knepp are beavers which would otherwise have been persecuted or shot by landowners in their region of origin
  • The beavers will be on Knepp estate land/National Trust land, and as such, Knepp estate/National Trust take full responsibility for their welfare under their licence conditions, and the maintenance of beaver fencing etc

10. How quickly do beavers breed?

  • Beavers breed once a year, and have an average of 3 kits
  • Beavers only breed at 2-3 years old
  • Beaver 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 (if not in fenced enclosures)
  • Once territories are established, population numbers only rise slowly
  • Beavers live in strict family groups, with only the dominant pair breeding
  • At high densities, territorial behaviour regulates their populations
  • Some beaver youngsters may choose to stay at home and help their parents rather than breed themselves when populations are at higher densities
  • Beavers have territorial battles, in which they will sometimes kill their rivals
  • 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

11. Is this a Rewilding project?

  • This is not a “rewilding” project. There should be a clear demarcation between re-wilding and the re-introduction of beavers to restore natural processes
  • The activities of beavers such as coppicing, damming and re-wetting are important natural processes. Although natural processes are a component of rewilding, the beaver re-introduction is not rewilding in itself.
  • The natural capital balance of beavers, and their contribution to wider rewilding projects will be studied as part of the trial
  • Rewilding is about restoring multiple natural processes across landscapes. Over the course of the beaver trial, we will be assessing the appropriateness of restoring this one natural process to the wider catchment area
  • Knepp is an independent, privately run rewilding project and operates as such. It is supported by multiple experts, organisations and a technical steering group. SWT play a key role in providing guidance on rewilding decisions at the site
  • Valewood is part of a wider Rewilding programme led by the National Trust
  • Sussex Wildlife Trust is partnering with Knepp and other stakeholders to provide essential professional support and guidance to beaver and wilding projects
  • Sussex Wildlife Trust is also supporting the appropriate restoration of beavers to other locations in wider Sussex

12. 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 suggests 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.
  • Man-made obstructions to fish passage have a far greater impact on migrating fish populations.
  • We work with other organisations to improve fish habitat and fish passage across Sussex.

13. What do Beavers eat?

  • Beavers coppice trees to create dams. Sometimes this is perceived as eating. 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
  • In summer, beavers graze mostly on riverside plants and grasses. In winter they feed mostly on tree bark and shoots
  • Beavers 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, and will leave the water to find these trees.
  • Beavers tend not to move far from fresh water so impacts are often very close to the riverbank, generally within 30m
  • Most native trees will naturally re-sprout when cut (coppicing). However in some instances browsing by deer and livestock, or flooding will prevent trees from re-growing
  • Special trees can easily be protected from beaver activity

14. Do Beavers prefer certain tree species?

  • 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
  • Sometime they will girdle (remove the bark around the entire base) of conifers for an unknown reason. One possibility is to obtain a much needed dietary nutrient

15. Do Beavers cut more at certain times of year?

  • 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
  • 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
  • Beavers do not hibernate, so they plan ahead and store a cache of edible sticks underwater near their lodge in order to be able to eat if their ponds freeze. Once a pond is frozen over and they can no longer access new trees, they will swim out of their lodge, grab an underwater stick, and bring it back to the comfort of their lodge to eat the bark
  • Remember that 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 suppl

16. 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
  • Most 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
  • Beaver are “Nature’s Engineers” and much of their tree felling is of trees such as willow and poplar which will naturally coppice and regenerate after felling

17. What does this project mean for people?

It is important that the Sussex Beaver Projects are open and reactive to pragmatic discussions with anyone that approaches them about beavers. Beaver management perceptions and issues change over time. We are regularly in touch with all those who will be involved with or affected by the beaver projects.

A range of natural capital benefits (natural benefits to the wellbeing of Society) will be provided by the Sussex Beaver Project. They include: -

  • Flood regulation
  • Water purification
  • Water regulation
  • Carbon sequestration
  • Soil formation
  • Erosion control
  • Ecotourism and Access to Nature
  • Ecological diversity

18. Where will the Sussex beavers come from? 

Beavers for the Knepp beaver project will be sourced from conflict areas around the Tayside catchment, Scotland. Wild beaver populations have existed there for at least 15 years and in some areas of low laying, prime agricultural land are leading to land-use conflicts. Under the SNH Beaver Mitigation Scheme some landowners qualify for lethal control licenses. As an alternative, trapping and relocation can be offered, so this project can provide a home for two pairs or small family groups. All beavers are live trapped by experienced ecologists and held at Five Sister Zoo for full health screening.  

The Valewood beavers are sourced from Devon via Derek Gow Consultancy.

19. How will we be working at a catchment scale / in the longer term?

  • The partners of the Sussex Beaver Project includes Government organisations, Non Government Organisations, Water Companies, Private landowners, Farming interests and Research institutions.
  •  All the partner organisations of the Sussex Beaver Project group agree that on balance, the long term re-introduction of beavers to parts of our river catchments is likely to have overall positive benefits to wildlife and to society.
  • To that end, the group is reviewing the options for a wider catchment re-introduction of beavers on the River Adur, and into wider Sussex.
  • The Sussex Beaver Project partners agree that free living beavers rather than beaver enclosures are the preferred option
  • If you would like to talk to Sussex Wildlife Trust about this, please contact 01273 494777

20. What would managed intervention for beavers look like?

  • At the end of the 5 year beaver licence, Natural England / DEFRA will review whether the beavers can stay or not
  • If the beavers are allowed to stay, and are allowed to live outside an enclosure, beaver management may need to be employed at some point
  • Sussex Beaver Project will follow national guidelines on Beaver Management Strategies
  • The Sussex Beaver Project recommends collaborating with local communities and land owners to develop a beaver management programme. Sussex Beaver Project will offer advice on established mitigation techniques ranging from tree protection, dam management, bank protection and burrow mitigation, or trap & re-home
  • If beavers are not allowed to stay in their enclosures, they will be rehomed following advice from beaver experts and discussions with NE
  • As beavers start to reach carrying capacity in their current enclosures, continual monitoring will identify older offspring that may not find a territory on their own. Any individual displaying signs of increased dispersal attempts, no longer being accepted within their family unit, or showing signs of requiring more (food) resources will be removed. 
  • For welfare reasons, because of their territoriality, it is not ok to leave new animals in the existing enclosures once obvious evidence of overpopulation begins to show
  • At this point, decisions will be made about what to do with the excess beaver population. There are a range of options which will be considered in this case including: -
    • Opening up other areas of land at Knepp / Valewood estate to beavers (the most likely option)
    • Taking beavers to other areas of land on the Adur / Wey catchment, or another Sussex catchment, where landowners have approved their release
    • Providing (licenced) seed populations of beavers for other projects in Britain
  • The Sussex Beaver Project agrees that it is likely to be in the interest of Government to NOT designate beavers as a protected species, but to liaise with local stakeholders to ensure that safeguards for beaver welfare are put into place

21. Are there any other beavers in Sussex?

At June 2020: There are one or two captive zoo populations of beavers in Sussex and the National Trust are considering beavers at other Sussex sites.

22. Can we see the Beavers?

  • Beavers live in burrows dug into river and pond banks. They sometimes live in lodges built out of sticks and mud. 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
  • You can arrange to go beaver watching with the landowners / Project leads of specific beaver projects in the evenings for a more intimate experience of the beavers
  • Knepp estate organises safaris to show people the Re-wilding project. See knepp.co.uk/glamping-camping-safaris for more details
  • For welfare reasons until the beavers become well established, we agree that all visits to the beavers will be supervised
  • Remote watching will also be implemented where possible
  • There are public footpaths through the re-introduction areas

23. Can we volunteer to help the beavers? 

  • There are a number of different ways that volunteers can help the beavers.
    This include :-
    • Helping to monitor the animals themselves (dawn and dusk)
    • Helping sort through trail cam footage
    • Helping with social media & you tube footage
    • Helping to monitor fence lines
    • Helping with other wildlife monitoring on beaver sites
    • Helping with fixed point and drone photography
    • Helping us to fundraise
    • GIS mapping of future beaver potential across Sussex
    • Be a beaver advocate & help people learn about beavers 

24. If you see any Beavers?

  • If you see a beaver outside the Knepp enclosure on the River Adur, contact 01403 741234
  • If you see a beaver outside the Valewood enclosure on the Wye catchment, contact 01428 652359
  • If you see a beaver anywhere else in Sussex, let Sussex Wildlife Trust know on 01273 494777
  • Please take careful note of any ear tags, and let us know the time, date and location of where you saw them, or their feeding evidence. If you can send a photo too, that helps

25. How long can the Beavers stay?

  • Valewood and Knepp estate have been granted a 5 year licence for the beavers. For Knepp, this licence became active in January 2020 when the licence was granted. Whether the beavers have been released or not (due to delays such as Covid 19), the licence will expire on Jan 2025
  • After this date, Natural England will make a decision about whether the beavers are allowed to remain
  • We have put clear exit strategies in place in the event that the impacts of the beavers are considered to be unacceptable to the majority of key stakeholders. This would involve the partnership rounding up the animals and bringing them back into captivity

26. Can we donate to the Beaver projects?

The Sussex Beaver Project area big financial and staff commitment for all those involved including Sussex Wildlife Trust, the National Trust and the Knepp estate.

  • Sussex Wildlife Trust is a small charity dependant on donations and membership. If you would like to support a Sussex beaver project financially, please see our donation pages or contact us on 01273 494777
  • Knepp Estate is a private estate who can be contacted through their main office
  • National Trust can be contacted below

27. Who do we contact for more information?

  • For the Knepp project, call the Knepp Safaris phone line - 01403 713230, or email - [email protected]
  • For Sussex-wide enquiries, call the Sussex Wildlife Trust WildCall number – 01273 494777, or email - [email protected] 
  • For enquiries about the National Trust Valewood beaver project, visit their Contact us page.

28. What monitoring is being carried out of the Knepp beaver trial?

  • Significant baseline monitoring is already in place in Sussex Beaver release sites
  • Other monitoring has already taken place to study the impacts of beavers on the ecology, hydrology and landscape of various British landscapes.
  • Each individual beaver release site has an agreed set of monitoring protocols set out in their licence agreement. Most sites are carrying out additional monitoring to their licence requirements. Completed surveys at Knepp include :-
    • Harvest mouse nest searches
    • Bird surveys
    • Aquatic plants surveys
    • Invert Kick sampling
    • EA electro fish survey
    • Bryophytes
    • Static bat detectors
    • eDNA aquatic invert sampling
    • GCN eDNA.
    • Flow gauge data collection including control site + weather station data collection
    • Drone photography
    • Fixed point photography
    • Adur wide feasibility study for beavers
    • Exeter university national beaver site monitoring
    • Scrub & tree cover digitization
    • Conchological studies.
    • We hope to also study beaver behaviour and ecology