Frequently asked questions

1. Are Beavers native to the UK and Sussex?

  • Eurasian Beavers are native to the UK, and were lost from the British countryside 400 years ago when they were hunted to extinction for their fur, meat and castoreum
  • Eurasian Beavers (Castor fiber) are naturally found across Europe and much of Asia
  • We recognise a native species to the UK as one that recolonised the British Isles after the ice retreated at the end of the last ice age
  • There is archaeological evidence of Beaver presence in Sussex

2. Where did the re-introduced Beavers come from?

  • All the Beavers for this project were sourced from UK born Beavers
  • The Knepp Beavers are from Scotland
  • The Black Down Beavers are from Devon

3. 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 , which in turn benefit a wide range of other 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 try and create pools using small dams
  • Trials in Devon show huge improvements to wildlife, water quality, flood reduction, sediment reduction and more where Beavers are re-introduced. In a 2.8 hectare plot in the Devon Beaver Trial over 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 it takes for floods to flow through the site from 15 mins to 1 hour
    > Enhanced the summer baseflow
    > 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.
    > 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 specific to Beavers that we no longer see in the UK, these include beaver meadows, where Beavers back water up into a pond which slowly silts up to create a wet meadow.
  • Beavers can play a key role in managing trees and other bankside vegetation
  • Estimates suggest that at least 80% of our wetland in Sussex have been destroyed, and that most 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 managing climate change and to the restoration of a healthy living landscape.  

4. 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 will determine the types and numbers of other species found in that environment. Without keystone species, the habitat (in this case wetland) would be dramatically different, usually far less healthy, and in many cases, would cease to exist. An analogy is the keystone in a brick arch. If you remove the keystone then the arch collapses. 

5. Where to Beavers live?

Beavers live in rivers and wetlands. They live and breed in burrows dug into riverbanks and sometimes in lodges (mounds) built out of sticks and mud.

6. Do Beavers eat fish? 

  • Beavers are entirely vegetarian (herbivorous) and do not eat fish
  • The natural wetland habitats that Beavers create often greatly help to increase natural fish populations, and to create habitat for lots of other species
  • 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

7. Don’t Beavers cause flooding? 

  • In most cases, Beaver damming does the opposite. Beavers in the right place can make rivers much less spatey, reducing flooding by holding water in areas where there is space for it, and then releasing it more slowly during drier periods
    > A project with the University of Exeter has studied the impacts of Beavers on water flow and flooding in detail. The results show a remarkable, positive effect on reducing flood peaks
    > Beavers coppice trees and will create dams along ditches, watercourses and culverts. This Beaver trial aims to assess the significance of these impacts in their release area, trialling techniques developed elsewhere to address conflicts
    > In order to store water and create their natural habitat, Beavers need to flood areas of land and create ponds – that is what they do. This can be managed so that they  create this habitat where flooding is wanted
  • Currently there are no free living Beavers in Sussex, so any flooding that takes place will be within a fenced enclosure, on land which has been expressly set aside to allow natural flood storage.
  • It is important to differentiate between the storage of water by Beavers in river headwaters, and the impact of Beavers on low lying land, where culverts and drainage systems may be critical to avoid flooding, and need to be kept clear of beaver debris
  • There will be low lying agricultural or developed areas in floodplains where Beavers might be discouraged. There are quick, easy and well tested ways of removing the risk of flooding by Beavers in unwanted areas, however this is unlikely to be an issue in Sussex for 10-20 years.
  • Beavers do not move far from rivers and streams so impacts are often very close to the riverbank, and very rarely more than about 30m away.

8. Are the Sussex Beavers captive or wild?

  • A little of both. The Knepp Beavers will be free living in a 250 hectare enclosure, with all the main river exits and entrances fenced off so that they can’t escape into the rest of the catchment. The Valewood Beavers will live in an enclosure of 2-4 ha
  • The Knepp estate is an ideal location for the trial as it was previously a farmed landscape which is being re-wilded. There is plenty of suitable habitat for the Beavers, and the site is remote enough from other infrastructure that we can observe their impacts on the wider river system, before considering whether it is a good idea to release them into the wider catchment / wider Sussex
  • We don’t envisage that Beavers will be encouraged in the wider river catchment for at least 5-10 years, whilst our resident populations breed and fill up the existing enclosures

9. How will we ensure the health and wellbeing of the Beavers? 

  • Our partners include Beaver experts from Devon and Scotland who advise us on the correct procedures to ensure that the Beavers are all healthy
  • The Beavers will be free living in their fenced landscapes, in areas which are larger than they would naturally need for a territory. Each Beaver site has been assessed to ensure that is has sufficient, healthy habitat for the Beavers to be able to thrive
  • We have professional vets, and staff who are educated in Beaver health and care. They can be called in in case of concerns for Beaver welfare
  • If necessary we will limit human access to key Beaver sites to avoid any distress to the animals, particularly when breeding
  • Some of the Beavers that we are translocating are Beavers which would otherwise have been persecuted or shot by landowners in their region of origin
  • Each release site has a Beaver handling facility where Beavers can be penned, and treated if they are found to be sick or injured. They will be held in these penning facilities until such time as they recover, when they will be re-released into their original enclosure

10. Do Beavers carry disease? 

  • The Beavers which were introduced to Sussex were all health checked to make sure that they do not carry any parasites or diseases
  • The Sussex Beavers are all healthy and free of any significant diseases, including the tapeworm Echinococcus and bTB
  • European Beavers have never been found carrying TB, but it was important to test them to reassure landowners. There is no evidence that Beavers carry bovine tuberculosis (bTB) either in the UK or Europe. As most mammals can be infected by bTB it is theoretically possible for Beavers to become infected. However, the natural behaviour of Beavers is such that it is highly unlikely that Beavers could act as an effective reservoir for the transmission of bTB to livestock species
  • Beavers live in the river and in riparian woodlands, and do not really come up onto grazed pastures, so they are unlikely to come in contact with cattle

11. Can we see the Beavers?

  • Beavers are nocturnal, quiet and relatively elusive animals, so it is not easy to see them. The areas into which they are being reduced are large, and it is likely that they will be difficult to see for some time as they settle in
  • The Beavers are living on quiet sub-catchments of the Adur and Arun rivers. Please respect the landowners and avoid disturbance to the Beavers by sticking to the public footpaths and by following the Country Code
  • 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
  • Please keep dogs on leads in the Beaver areas. 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!
  • There are sanctuary areas where the Beavers can live undisturbed where there are no footpaths, so please avoid trespassing
  • You can arrange to go Beaver watching via Knepp estate or the National Trust. Beavers are generally nocturnal 

12. What do Beavers eat?

  • Beavers are herbivores – they only eat plants
  • In summer, Beavers graze mostly on riverside plants and grasses. In winter they feed on tree bark and shoots
  • The majority of the trees and vegetation that Beavers feed on, naturally re-sprout when cut – this is called coppicing

13. What tree species do they eat?

Beavers have a definite preference for certain trees. Preferred tree species include alder, aspen, apple, birch, cherry, cottonwood, poplar and willow. 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. Sometimes they will girdle (remove the bark around the entire base) of conifers for an unknown reason. One possibility is that they obtain some dietary nutrient that they need from the bark.
Beavers particularly like willow and aspen trees, but are less keen on alder. They might take fruit trees, particularly apple, and poplar trees if these are close to watercourses.

14. Aren’t we trying to plant more trees for climate change – if so, shouldn’t we be protecting trees from Beavers? 

  • Most of the trees that Beavers eat, are trees such as willow and alder which naturally coppice. This means that when one stem is cut, it naturally puts out several new shoots as a replacement – thus increasing overall tree cover in the majority of cases
  • Beavers also place cut twigs and branches into their dams and lodges. Many of these twigs and branches will re-sprout, taking root and growing as new trees – so they also plant new trees!
  • Beavers are fantastic at creating a range of habitats from ponds to meadows, to woodlands. On balance, their effect on the natural environment is to create much more carbon storage, than is destroyed
  • Occasionally larger, or specimen trees will be cut by Beavers, but these can normally be spotted before they are fully cut down. Special trees can easily be protected from beaver activity using simple chicken wire netting or sand paint

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

Beavers cut down the most trees in late autumn to stockpile a food cache for the winter. Beavers do not hibernate, so they plan ahead and store edible sticks underwater near their lodge in order to be able to eat if their pond freezes. Once the 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.

16. How far from water do Beavers cut trees?

Beavers are well adapted to water and evolved over millennia to use water as a defense 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 100 feet of the water. If Beavers seasonally deplete the supply of food trees close to the pond’s edge they often raise the height of their beaver dams to bring the pond closer to more distant trees. 

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 more easily and more safely to their pond using their ‘canal’. 

17. How quickly will Beavers reach population capacity at their release sites? 

  • Beavers spread fairly slowly. The kits are vulnerable to predation, and their territorial behaviour regulates their populations
  • Beavers are very territorial, and their populations are limited by territorial battles, in which they will sometimes kill their rivals
  • This territoriality regulates the size of the Beaver population that a river can support
  • A Beaver territory is usually no more than a few hectares, so the Knepp release site will take a number of years to fill. It is likely that a few more Beavers will be released at Knepp, so that the genetic integrity of the population can be maintained, and so that in-breeding doesn’t occur. To do this, consent from Defra will need to be sought
  • Beaver young are vulnerable to predation by Foxes, birds of prey and even occasionally Otters
  • Beavers breed once a year, and have an average of 3 kits
  • Beavers only breed at 2-3 years old

18.  Is this part of the Knepp Re-Wilding project?

  • The Sussex Beaver releases are not a “rewilding” project per se, but they are an integral part of restoring more natural landscapes using nature led recovery to Sussex
  • Knepp is an independent, privately run rewilding project, and they are the legal holders of their beaver licence. There is a clear demarcation between the Knepp re-wilding project, the Valewood wilding project, and the re-introduction of Beavers to restore natural processes
  • The Beavers will be on Knepp estate / National Trust land, and as such, Knepp estate / National Trust take full responsibility for beaver welfare, and the maintenance of beaver fencing etc
  • 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
  • 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. The natural capital balance of Beavers, and their contribution to wider society will be studied as part of the trial

19. What is Sussex Wildlife Trusts role in the Sussex beaver re-introductions? 

  • Sussex Wildlife Trust is partnering with Knepp and other stakeholders to provide essential professional support and guidance to the Sussex beaver re-introductions
  • Sussex Wildlife Trust has provided expert advice, staff time, and professional support of the Sussex Beaver Trials, in recognition of the valuable role that Beavers can play in restoring wild nature to Sussex
  • Sussex Wildlife Trust is also supporting the appropriate restoration of Beavers to other locations in wider Sussex
  • UK beaver projects so far have been a huge success.  Sussex Wildlife Trust and the other project partners are proud to support this local project, and to provide a great way forward
  • The Wildlife Trusts nationally support the restoration of Beavers to the UK for the benefit of people and wildlife

20. Will the Sussex beaver trials be monitored?

A great deal of monitoring has been carried out of the two beaver release sites, in advance of their release. This is to ensure that baseline data is available that we can compare to information collected after the Beavers. We want to study the impacts of Beavers on the ecology, hydrology and landscape of Sussex. Further information will be gathered after the beaver releases.  
This includes some of the following :

  • Drone fly overs of habitat
  • Fixed point photography
  • Camera trapping
  • eDNA survey
  • Hydrological information (water levels and flows etc)
  • Surveys of bats, harvest mice, aquatic invertebrates, birds (including turtle doves), moths, bryophytes, plants, fish, snails, reptiles and amphibians and more
  • GIS mapping of beaver potential, and potential beaver conflicts at a catchment scale

Exeter University are studying the Sussex beaver trials as part of a UK-wide project to measure the impact of Beavers in a range of local landscape types.  
A great deal of further information and research is available from the Devon Beaver Trial, the Scottish Beaver Trial, and other beaver projects around Britain. 

21. What does this project mean for people?

Sussex Wildlife Trust hope that local people and future generations will once again be able to get to know these intriguing animals as a local Sussex species. Local people are unlikely to see, or experience any detriment from the Beavers being there. The organisations involved with introducing the Beavers are keen to engage with local communities to ensure that they have all the knowledge and support that they need to understand, and appreciate the value of the Beavers.  

There are a whole range of natural capital benefits that will be provided by the Sussex beaver trial. These are benefits to wider society as well as to wildlife. These include :-

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

22. Do you intend to release Beavers into the wild?

  • All beaver introductions are currently licenced by Natural England / Defra, and no beaver introductions are allowed without a full and complex licence application. Currently Defra are not licencing wild beaver releases, only fenced releases
  • There are a large number of both free living and captive Beavers already living in England, Wales and Scotland. Devon Wildlife Trust have Defra and local community support to study the effects of the free living Beavers on the River Otter in Devon
  • The partners of the Sussex Beaver Trial include Government organisations, Non Government Organisations, Business, Private landowners, Charities, Farming organisations and Research institutions. All the partner organisations of the Steering group, except the NFU, agree that on balance, the longer 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 Sussex Steering Group will review the options for a wider catchment re-introduction of Beavers on the River Adur, and potentially wider Sussex at an appropriate moment in time – probably towards the end of the current 5 year beaver trials (2025)
  • On the whole, the project partners agree that free living Beavers rather than beaver enclosures are the preferred option

23. Can the Beavers escape?

  • Both beaver release sites are heavily fenced with bespoke fencing to prohibit the escape of Beavers
  • The sites have been fully risk assessed to see if there is any likelihood that Beavers could escape, and preventative measures have been taken under licence to ensure that they do not
  • In the unlikely eventuality that Beavers escape (i.e. storm damage to a fence), then there are trained volunteers and professionals who can advise on how to spot, and re-capture an animal. Vets will be on hand with professional equipment if this should happen
  • Regular fence checks will be carried out by staff and volunteers on the Beaver release sites, particularly after storm events
  • At Knepp Estate, should Beavers escape, the most likely place that they will go is onto another part of the estate

24. What happens to the Beavers at the end of the 5 year licence? 

  • At the end of the 5 year beaver licence, Defra will review whether the Beavers at Knepp/Valewood can stay or not. If Beavers are not allowed to stay on the site, they will be relocated using veterinary assistance to an appropriate alternative, preferably wild, location in England
  • There is a clear exit strategy 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 or relocating them to another site in England
  • Although unlikely to happen for a long time, once the Beavers at Knepp / Valewood reach carrying capacity in their current enclosures, decisions will be made about what to do with excess animals which are born into a saturated set of beaver territories
  • For welfare reasons, because of their territoriality, it is not ok to leave new animals in existing enclosures once obvious evidence of overpopulation begins to show

25. Can you help with the Sussex Beaver Projects?

There may be opportunities to support the Sussex Beaver projects. These include :-

  • Giving grants and financial support to Sussex Wildlife Trust / the National Trust to enable us to provide education, community engagement and expert advice on Beavers
  • Volunteering to monitor the Beavers and their fenced enclosure for Knepp estate – please contact them through their website.
  • Volunteering to support the Beavers at the National Trust in Valewood. Please contact the National Trust
  • Providing land for potential further Beaver re-introductions – please contact Wildcall on 01273 494777

26. Who do we contact for more information?

To contact the project use the Sussex Wildlife Trust WildCall number – 01273 494777 , or email

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