Release of Casualty Deer (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: Capreolus capreolus - Western roe deer, Cervus elaphus - Red deer, Cervus nippon - Sika deer, Dama dama - Fallow deer, Hydropotes inermis - Chinese water deer, Muntiacus reevesi - Chinese muntjac.

These species are from the family Cervidae.

  • Deer fit for release are strong and not easy to handle.
  • Very careful planning is required to ensure that release is achieved with the minimum of stress and trauma to both deer and handlers.
  • The release of both Cervus nippon - Sika deer and Muntjac (Muntiacus reevesi - Chinese muntjac) without a licence is prohibited under the Wildlife and Countryside Act 1981, Section 14, as both are listed in Schedule 9 of the Act.(J35.147.w1,  W5.Jan01)


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

  • Provide natural food to minimise the risk of gastro-intestinal upset following release. Locally available browse for browsers and access to grass for grazers ( See: Feeding of Casualty Deer).

  • Minimise habituation to humans and domestic animals particularly dogs.

  • (P19.3.w2)

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 for the species. 
    • 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)

Factors which may prevent release include:

  • Animals which are tame, particularly hand reared stags or bucks, as they may be a serious danger to the public.
  • Does or hinds which have suffered pelvic injuries restricting the birth canal, as natural parturition (birth) may not be possible.
  • In some species of deer, particularly roe deer (Capreolus capreolus - Western roe deer), which have been castrated, "perruque" antlers form which may restrict vision and lead to reduced fitness. This has been reported to result in the death of the deer. (B158) Castration interferes with the normal physiological control which may result in distorted antler growth known as "perruque". 
  • Blindness.
  • Loss of a limb (although individuals are known which have survived and bred in the wild while lacking a limb or following accidental amputation of e.g. both forefeet).
  • (P19.3.w2)

Selecting a release site:

  • Release should normally be back where the deer was found, or, e.g. if the individual was found in an urban area, in the nearest suitable/safe habitat.
  • Release of muntjac (Muntiacus reevesi - Chinese muntjac) under licence must occur within 1km of the site the individual was found.
  • Permission of the landowner should be granted before deer are released onto their land at a site distant from the original location.
  • (B151, B224, D27, P19.3.w2)

Timing of release:

  • Priority should be given to releasing deer as rapidly as possible (a few days rather than weeks) as they may be problematic long term patients and tend to be particularly stressed by a captive environment.
    • It may be prudent to release deer with minor wounds which are still healing (e.g. lacerations sutured with absorbable sutures), although consideration must be given to the possibility of wound infection and fly strike (Myiasis) following release.
  • Delay in release may result in the deer losing its territory or in the case of social animals its place in the social group.
  • (P19.3.w2, V.w26)

Type of release:

Hard release:

  • Deer are usually released by this method.
  • Deer, particularly of the larger species, which have been maintained in paddocks prior to release may require tranquillisation by dart for handling and transportation to the release site.
  • Muntiacus reevesi - Chinese muntjac, Hydropotes inermis - Chinese water deer and Capreolus capreolus - Western roe deer may be transported to the release site within appropriate carrying boxes. (see: Wildlife Casualty Handling and Transport)
  • Dama dama - Fallow deer and Cervus elaphus - Red deer will require an appropriate-sized box trailer or a horse box or similar vehicle for transportation tot he release site.
  • (B151, V.w5)

Soft release:

  • When a deer originated a long distance from the place where it has been treated/rehabilitated, it may be better to release into suitable habitat close to the rehabilitation centre in order to avoid a long journey back to the original site.
    • In this situation soft release may be possible, with release being made by leaving the paddock gate open and food made available until the animal stops returning.
    • (P19.3.w2)
  • Soft release is generally appropriate for hand reared deer.
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.
  • 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.
  • Diurnal species should be released in the morning, giving them a full day to explore and look for food and shelter before nightfall.
  • Nocturnal species should be released at night.
  • Release should preferably take place during a period of fine weather.
  • Marking of deer for post release monitoring may be done by:
    • Numbered coloured plastic ear tags (designed for sheep or cattle).(P19.3.w2)
    • Short-term: paint or coloured adhesive tape on antlers. (P19.3.w2)
    • Patch of clipped hair. (P19.3.w2)
    • A licence may be required for some forms of marking. (J35.147.w1)
    • See: Legislation relating to Wildlife Casualties
Complications/ Limitations / Risk
  • Deer fit for release are strong and not easy to handle.
  • 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.
  • 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
  • Knowledge of the natural history of the deer species is important for selecting an appropriate release site other than the animal's original location.
Cost/ Availability
  • Soft release may involve a considerable time investment.
  • Soft release may be expensive in terms of construction of appropriate temporary accommodation at the release site.
  • 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. 
  • (J35.147.w1, B156.21.w21, B223, W5.Jan01)
  • The release of both Cervus nippon - Sika deer and Muntjac (Muntiacus reevesi - Chinese muntjac) without a licence is prohibited under the Wildlife and Countryside Act 1981, Section 14, as both are listed in Schedule 9 of the Act.(J35.147.w1,  W5.w1.Jan01) Licences may be issued by DEFRA for the release of muntjac within the 12 "Core counties" defined by JNCC (Bedfordshire, Berkshire, Buckinghamshire, Cambridgeshire, Essex, Hertfordshire, Leicestershire, Norfolk, Northamptonshire, Oxfordshire, Suffolk and Warwickshire).(V.w29) See: Wildlife Casualty Legislation: Release of Animals  for further details including the address to write to regarding licences.
Author Debra Bourne
Referee Becki Lawson and Suzanne Boardman

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