TECHNIQUE

Release of Casualty Meles meles - European badger (Wildlife Casualty Management)

Summary Information
Type of technique Health & Management / UK Wildlife Casualty Management / Techniques:
Synonyms and Keywords N.B. This information should be read in association with Wildlife Casualty Release which contains background information together with links to the Electronic Library and Organisations (UK Contacts). The related Species pages contain similar linkages.
Description This page has been prepared for the "UK Wildlife: First Aid and Care" Wildpro module, and is designed for the needs of the following species: Meles meles - Eurasian badger
  • Badgers should be released as soon as possible for the maximum chance of survival: there is a reduced chance of survival following confinement for prolonged periods. (B152, B157.w10, D25)
  • It is important to release badgers in their original territory whenever possible: exactly where found if this is identifiable. Records should include e.g. grid references at the time of presentation. (B152, B157.w10, D24, D25)
  • Collaboration with the local badger group (may be contacted via the National Federation of Badger Groups (NFBG)) is recommended for all releases and may be essential to ensure sufficient support for care of badger groups undergoing soft release.(B152, D24)
  • If a badger is to be released to a new territory it should be TB tested prior to release. (see: Mammalian tuberculosis in badgers).(B157.w10)

Pre-release:

  • No pre-release preparation is required if these animals have been in care for a short period of time.

Soft release of a group of badgers:

  • A group of badgers must be formed in captivity prior to release.
  • Soft release is particularly important for hand reared badgers.(V.w26)
  • Requires accommodation appropriate for group housing of badgers. (P25.4.w4)
  • Choices must be made regarding the appropriate animals to integrate.(P25.4.w4)
  • The group must include animals of both sexes.(B152)
  • Integration should be performed at a site new to all the badgers so that none of the individual badgers can already consider the territory to be theirs to defend.(P25.4.w4)
  • Integration may be assisted by moving all animals into the new sett while anaesthetised, manually mixing their scents and mixing the scent in with the bedding. (P25.4.w4)
  • The enclosure containing the sett should be sufficiently large to hold the intended group. (see: Accommodation of Meles meles European badger)
  • The group should be fed at dusk and otherwise be left undisturbed. This is particularly important if dealing with tame or habituated badgers. (B152)

Release assessment/criteria:

  • Released mammals:

    • Must be able to recognise, catch, manipulate, consume and digest their natural diet.
    • Must be capable of normal locomotion (movement) and have sufficient fitness for sustained activity.
    • Must have adequate sensory ability (sight, smell, hearing).
    • Must be of an appropriate weight for the age, sex, and time of year. 
    • Must have a satisfactory hair coat.
    • Must show appropriate wariness of humans and domestic animals.
    • (P19.1.w10, P24.233.w11, J35.147.w1, D27)
  • Appropriate health checks should be carried out prior to release. A careful assessment (risk analysis) must be made as to the risks of released animals introducing novel pathogens (disease agents) into the wild population/environment.
    • These pathogens may have been acquired from domestic animals, other wildlife casualties or humans whilst the animal was in captivity.
    • The health checks should be designed to minimise the risk that pathogens posing a threat to wild populations of this or other species will be introduced into the environment when the animal is released.
    • (V.w5, V.w6, P28.2000.w1, J15.20.w3)
  • Prior to release an assessment must be carried out to determine that the badger is:

    • Physically able, particularly the ability to procure worms as a major part of the diet; this requires sufficient apposing (meeting one another) incisor teeth. (P25.3.w3)
    • Mentally sound – not obviously brain damaged e.g. walking in circles. (P25.3.w3)
  • TB Testing:

  • Sample: 1-2 ml of blood, collected from the jugular or (second choice) cephalic vein, into a plain tube. Allow to clot then spin and separate serum. Serum is then sent for testing.
  • Send to: Veterinary Laboratories Agency Langford, Langford House, Langford, Bristol BS40 5DX. Tel: 01934 852421, Fax: 01934 852981.(See: Veterinary Laboratories Agency)
  • Test should be carried out on three occasions, preferably at least four weeks apart.
  • The first test should be carried out early, with the cub identichipped when the sample is taken to allow a unique identity number to be sent with the sample. The cub should be kept isolated until the results of this test are known.
  • The second test should be carried out at least 4 weeks later. Tattooing (which requires general anaesthesia) may be carried out under licence at this time. The unique identifying number sent with the first sample should also be sent with this sample.
  • The third test should be carried out as close to release as is practical. The animal should be anaesthetised so that a full health check can be carried out and tattooing undertaken if this has not been done previously. The unique identifying number sent with the first sample should also be sent with this sample.
  • (D50)

Selecting a release site:

  • Hard release: Release at the site of origin or the nearest safe point (e.g. not in the middle of a main road); this will be facilitated if the site was marked at the time of capture.(B152, D25, P25.4.w4, D27)
  • Soft release of a group of badgers: Choose a suitable site vacant of badgers. N.B. This requires extensive research together with knowledge of badger natural history and a detailed habitat survey.
  • The site should not be too close to existing setts. (P25.4.w4)
  • There must be no or very little badger activity in a radius of about 2km from the intended releases site.(B152)
  • It is important to know why the site is vacant and whether any factors which made it unsuitable badger territory have been resolved/removed. (B152, P25.4.w4)
  • The site should not be close to hazards such as a main road or where a main road or development is planned. (P25.4.w4)
  • Permission of the landowner must be sought and agreed; it is important to ensure that local landowners in the area are supportive and welcome badgers on their land. (B152, P25.4.w4)
  • Choose a site away from the public but where monitoring is possible and someone is nearby to make sure that the release pen is left alone and not tampered with.(B152)
  • An artificial sett must be built unless an abandoned sett is present at the release site. (P25.4.w4)
  • An abandoned main sett should be used if available; however it is important to be sure that it is abandoned, to know why it was abandoned and that the reasons for the abandonment (e.g. persecution) no longer apply.(B152)
  • An artificial sett may also be appropriate if the land around the chosen natural sett is unsuitable for fencing off. (B152)
  • Soft release of badger cubs: may be released from their rearing site, if the area is appropriate (rearing from inappropriate sites should be avoided if this method of release is to be used). (B152)

Timing of release:

  • Hard release: Release as soon as possible, well after dark; in the middle of the night if the capture/release point is in a busy traffic area.
  • Soft release of a group of badgers: Move to the release site in late summer and release in autumn if possible, as badgers are generally less active at this time, therefore reducing the chance of individuals wandering from the release site and wild badgers wandering in and disrupting the group.(B152)
  • Soft release of cubs from the site of rearing: Begins in late summer; the process is likely to take until late winter or early spring.

Type of release:

Hard release:

  • Immediate release may be suitable for an uninjured badger which has been trapped overnight in e.g. an empty swimming pool or other hole, a shed or similar building.
  • Hard release is also suitable for badgers which have been in captivity for a short time (days to weeks).
  • Release at the site of origin; this will be facilitated if the site was marked at the time of capture.
  • Release well after dark; in the middle of the night if the capture/release point is in a busy traffic area.
  • Place the transport container on the ground and wait a few minutes to give the badger a chance to orientate itself with respect to its surroundings.
  • Open the container and allow the badger to emerge at its own pace.
  • (B152, D25, P25.4.w4)

Soft release of a group of badgers:

  • An appropriate fence must be built around the sett, enclosing an area sufficiently large to accommodate the release group for a period of at least 2-3 months.(P25.4.w4) The group should be released into the enclosure quietly at night.(P25.4.w4)
  • Release the badgers from their carrying cages directly into the sett and plug the openings loosely with straw until dusk.(B152)
  • The group must be fed while the fence is in place.
  • The boundary must be checked daily in the period before release to ensure that it remains badger-proof. (P25.4.w4, V.w26)
  • Close monitoring of the badgers’ behaviour should be carried out; this may allow valuable lessons to be learned for future releases.(P25.4.w4)
  • Removal of the fence should take place at night and quietly with minimal disturbance. (P25.4.w4)
  • The group should be kept confined for four to six weeks;(B152); one to two weeks. (B151)
  • Daily feeding and watering is required during the period of confinement.(B152)
  • The number of people involved with feeding should be minimised.(B152)
  • Casual visitors to the release site should be discouraged.(B152)
  • Once the fence is removed, feeding must continue for some time; reduction in food provision should be gradual.(B152)

Soft release of individual or littermate hand reared cubs:

  • An individual cub or littermates may be released from their rearing site, if the area is appropriate (rearing from inappropriate sites should be avoided if this method of release is to be used). (B152)
  • Move to outdoor enclosure or outbuilding by May/June (when large enough); minimise human contact from this time (one person only, no playing or handling).
  • The cub or cubs should be taken for walks around the local area from June onwards and given opportunities for foraging during such walks. (B152)
  • From late summer the cub(s) should be allowed to wander at night on its own; a badger gate set 60cm above ground level, reached by a plank on either side may be used to allow the cub(s) to enter and leave a fenced off area around the rearing shed/pen while discouraging wild badgers from following it into the pen. The cub(s) must be taught to use the gate safely. (B152)
  • The cub should be mainly self-feeding by the end of summer but supplementary food should be provided until the cub(s) no longer return to the release site. This is likely to be late winter or early spring, i.e. at about a year old. (B152)

Monitoring:

  • Activity should be monitored following release; this may include e.g. noting of new activity at a previously-deserted sett. (P25.4.w4)
  • Cubs should be tattooed as early as possible using the National Federation of Badger Groups procedure and also microchipped to ensure they are individually and permanently identifiable.(D50) The year and number for tattooing are issued by, Secret World Wildlife Rescue or the RSPCA West Hatch Wildlife Hospital. Tattooing of badgers may only be performed under licence.
Appropriate Use (?)
  • Soft release is particularly important for hand reared animals, particularly of species which need to learn about their surroundings (e.g. food sources) and/or learn survival skills such as hunting.
  • Soft release is also suitable for animals which have been in care for prolonged periods.
  • Soft release may compensate for difficulties of newly released animals finding food and shelter, particularly in a new environment and/or at a time of reduced physical fitness/stamina.
  • Hard release is most appropriate for animals which have been held in captivity for only a short time, for adult animals and for animals being released back into their own territory.
  • Opinions vary on the length of time after which a badger is unlikely to successfully re-integrate into its original group.(P25.4.w4)
  • The individual animal must, at the the time of release, be healthy, have a reasonable level of fitness and be able to fend for itself in the wild.

Suitable animals for relocation and soft release include:

  • Cubs which have been injured/orphaned and hand reared.
  • Adults which cannot be released at their original site due to:
    • Insufficient information regarding their original location.
    • Individuals which have undergone long term treatment (e.g. months).
    • Where the original site has persistent ongoing problems with e.g. snaring or persecution.
    • Where the site at which the badger was found is obviously unsuitable.
    • Animals which have been badly bitten and an assessment made that reintegration into the home sett is unlikely and following expert advice it is considered appropriate to perform release at an alternative site.
      • It is vital that the condition of each individual territorial wound badger be assessed carefully to determine whether euthanasia, treatment and release at the site of origin or, least commonly, translocation for soft release at a new area is appropriate.
  • (B151, P25.4.w4, V.w26)
Notes
  • Nocturnal species should be released at night.
  • Release should preferably take place during a period of fine weather.
  • Opinions vary on the length of time after which a badger is unlikely to successfully re-integrate into its original group.(P25.4.w4)
  • All-cub group: Integration is usually relatively easy. Transfer to the release site as soon as possible so that they grow up there and good site fidelity is likely. Cubs are unlikely to be able to defend their territory.
  • Mixed age group: integration may be more difficult. There is a risk of cubs being attacked by adult males. The advantage of a mixed age system is that cubs are in the company of mature adult badgers which can act as "mentors" to assist them in learning to get to know the release area and learning to forage.
  • Consult with landowners, relevant Statutory Nature Conservation Agency (English Nature, Scottish National Heritage, Countryside Council for Wales, Environment and Heritage Service) and Ministry of Agriculture Fisheries and Foods (now DEFRA) prior to release.(B152)
Complications/ Limitations / Risk
  • Hard release is least appropriate for juveniles which have been hand reared, particularly species for which learning about their environment and/or social skills are important.
  • Hard release may also be inappropriate for adults which have been maintained in captivity for prolonged periods and/or are being released at a site distant from their original location.
  • There are doubts as to whether individual adults released to a new location, particularly males, would ever rejoin a social group; survival rates of such animals may be low. (P25.4.w4)
  • If a badger is to be released to a new territory it should be TB tested prior to release (see: Mammalian tuberculosis in badgers).(B157.w10).
  • A badger with severe territorial bite wounds may not be reaccepted into its original sett even if returned promptly. (P25.4.w4)
  • There is a risk of animals dispersing from a soft release group after release; this can be reduced by keeping the group together for a relatively long period before release.(P25.4.w4)
  • Site desertion/group dispersal is more likely to be a problem with adults than with cubs.(P25.4.w4)
  • Disruption of release by badgers digging out of release pens; this is more likely to occur with adults than with cubs.(P25.4.w4)
  • Loss of territory following release: a group composed solely of cubs is unlikely to be able to defend the territory against neighbouring groups.(P25.4.w4)
  • Insufficient breeding potential: a group of cubs only may not have sufficient numbers of animals surviving long enough to breed: badgers breed only at 3-4 years old and mortality averages 60% in the first year and about 30% in subsequent years.(P25.4.w4)
  • Release may not be appropriate for elderly badgers with extremely worn teeth as they may be unable to feed themselves effectively. Euthanasia may be more humane for such animals.
  • There is a risk of disease transmission when translocating animals. (P25.4.w4)
  • There is a particular risk when relocating badgers of translocating bovine tuberculosis (TB). (see: Mammalian tuberculosis in badgers) (P25.4.w4)
  • It is important that badgers to be translocated are adequately tested for TB before they are formed into a group or released. (P25.3.w3, P25.4.w4)
  • Released animals may be at risk of contracting disease if there is an ongoing disease problem in the wild population at the time of release.
  • The wild population may be at risk from novel pathogens (disease agents) carried by a rehabilitated animal. These pathogens may pose the greatest threat to free-ranging populations if the animal is to be released at a site distant from its original location therefore increasing the likelihood of spread of disease. It is important to remember that the casualty wild animal may have acquired disease from domestic animals, other wildlife casualties or humans whilst in captivity. 
Equipment / Chemicals required and Suppliers
Expertise level / Ease of Use
  • Considerable expertise is required for planning and conducting soft release of badgers.
  • Expertise is required for the construction of holding accommodation and pre-release pens.
Cost/ Availability
  • Soft release may involve a considerable time investment.
  • The construction of holding facilities and release enclosures is expensive.
  • Costs of appropriate health screening.
Legal and Ethical Considerations
  • The potential risks to the individual being released and to the wild population into which it is being released (also to domestic animals) must be considered before release is undertaken.
  • The potential risk to humans and pets from habituated/tame individuals must be considered.
  • An offence may be committed under Section 1 of the Abandonment of Animals Act 1960 if a released rehabilitated animal does not have a reasonable chance of survival (i.e. a chance similar to its non-rehabilitated peers). 
    • This may include release at an unsuitable site, in the wrong territory, unfit, not having learned to hunt, at the wrong time of year etc.
  • Protection of Badgers Act 1992: "Section 5: It is an offence for any person not authorised by licence to mark or attach a ring/tag/other device to any badger. NOTE: Researchers can be granted licences to mark badgers for purposes of study." (W5.Jan01)

(J35.147.w1, B156.21.w21, B223, W5.Jan01)

Author Debra Bourne
Referee Becki Lawson and Suzanne Boardman
References

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