Rehabilitation of Wild Animals

For time unknown, man has cared for disadvantaged animals and taken them into his care. Although such animals have received and benefitted from the timely help given, there is now an increasing consciousness to release such animals and return them back to nature. Most of the rescued animals had previously either been kept as pets, ended up as exhibits or remained in lifetime care centers due to a lack rehabilitation efforts and the resulting lack of release potential.

Animals that have been in human care, particularly hand-raised animals, lose some of their survival instincts and are likely to have lower survivability. Rehabilitation has therefore emerged as a science to help equip disadvantaged animals with the ability to survive in the wild after completing their recovery periods in captivity.

The purpose of the rehabilitation is to encourage the expression of the animal’s innate instincts and give it an opportunity to learn behaviors that will be beneficial for its survival in the wild. In the case wild animals, since we cannot ‘teach’ them the necessary survival skills, rehabilitation is often achieved through a process of providing enrichment and the opportunity to express their natural behaviors.

Directly or indirectly, this process must also encourage independence and the need to shy away from human contact. In predatory animals, rehabilitation would also include the ability to recognize and hunt natural prey; while in prey species, it is the recognition of the approach of danger and timely escape from falling prey themselves. Rehabilitation must also take into consideration individual differences within the species and equip individuals at its best.

Owing to the consciousness of rehabilitation and release, various protocols are now in place to maximize an animal’s survival after release. Rehabilitation, however, is not a perfect science yet. Protocols are readily available for many species, yet, hard to come by for many others. Often, it is a combination of prior experiences, the species biology and the responses of the animal in concern that leads to the formulation of your own protocols – the aim being the animal’s self-reliance and survival in the wild.

The process of rehabilitation

 

Creating independence

Self-reliance is crucial for any wild animal’s survival. The first and foremost step towards making a wild animal independent is withdrawing its contact and dependence on human beings. Should any animal remain dependent on humans beyond the period of its placement in captivity, it will greatly hamper its ability to adjust to the conditions of the wild.

There is no doubt that animals in captivity are directly or indirectly dependent on us is many ways. Behavioral manifestations of such dependency such as begging, following people, or simply seeking our human company must never be encouraged in an animal that is to be released. Such behaviors may be acceptable for animals placed in lifetime care centers but is counterproductive for animals that are to be released. A human must never directly be associated with the provision of their basic needs. For example, food may be left in a corner of the enclosure without calling for the animal’s attention. Interaction must gradually be withdrawn after weaning and the animal must be encouraged to interact with other natural stimuli.

Dependency is most commonly seen in wildlife orphans that come in at an early age and are hand-raised. These babies have seen nothing else in their lives and it is natural for them to be closely bonded with their parents – in this case, their foster parents. Yet, it must be remembered that most animals in nature become independent at an early age. We must strive to wean off contact at the age the animal would naturally become independent. This is easily achieved as most animals leave their natal place and disperse once older.

Social species are an exception to this rule due to their complex social dynamics. Even though they may be physically old enough, like us humans, they are dependent on other members of their group. Independence in such species is best achieved by creating dependence on another – this may simply be done by housing individuals of the same or similar species together. Such methods may be used for nonsocial or solitary species too but they often seem indifferent to its benefits.

Expression of inherent behaviors

There is a huge difference in simply holding on to an animal until the appropriate time and age for release, and holding on to an animal while giving it the opportunity to express its natural behaviors. There is currently a growing consciousness to provide a better quality of life for the duration that any animal spends in human care which has resulted in better housing facilities and enriched lifestyles for all captive animals. While any enrichment or habitat modification will prompt a behavioral response, it may not always encourage the natural behavior of the species in the wild.

The behavioral adaptations of each species have evolved to best suit their environmental conditions and maximize the survival of each individual animal. While in captivity, such adaptations lose their significance as their expression is no longer of benefit to the animal. The animal in turn learns new behaviors that may be more advantageous for its new lifestyle. Such new behaviors become deeply ingrained over time. Consequently, the animal exhibits the ‘new’ behavioral traits even after release in its natural environment.

Animals in captivity may not shy away from human contact; instead, they may actually follow and beg for treats. While such behaviors may give them added benefits while in captivity, they will be unfavorable after release. Again, an arboreal animal that is used to coming down for its daily meals will tend to do so even after release, even if it can meet all its needs without descending from the tree – thus, exposing itself to terrestrial predators.

It is therefore essential to encourage the animal’s innate behavioral responses which will be beneficial of its survival after release by providing natural stimuli and minimizing unnatural, especially anthropogenic, stimuli. The points below will all help to encourage the expression of an animal’s inherent behavior traits.

Enclosure designs to assist rehabilitation

Devna Arora - Habitat enrichment

The way an animal is housed plays a big role in the development of an animal’s behavior and they must hence be housed in conditions that are most natural for them. Although all baby animals are always housed indoors, each baby must be housed accordingly to the nesting habits of the species. Cavity nesters must be kept in closed baskets and boxes as they feel more secure when they are completely covered, while those that nest in open spaces may be housed in open baskets or boxes. Outdoor enclosures must provide a gradient of habitats which for example include trees, small ponds, rocks, etc. This not only helps the animals to familiarize themselves with various habitat conditions but also them to develop its physical agility and maneuverability. Birds must have ample perches (all made of natural wood) at various heights that allow hopping and landing, yet, they must be spaced to permit adequate space to fly.

Another point of consideration is hygiene and handling of animals in enclosures. All enclosures must allow periodic cleaning of the enclosures and it may be necessary to temporarily trap or shift animals into another space while doing so. Rather than chasing an animal or entering the enclosure with inadequate safety equipment, the animals may simply be channeled into another space. Most enclosures have trap cages and secondary smaller enclosures attached – this facilitates handling the animal when required. As a routine, the animals must be encouraged to move through these traps and secondary enclosures – this is particularly helpful for large animals and carnivores. Sliding gates may also be used to achieve the same and the animal may simply be blocked in its resting space while maintenance work is completed. It is also helpful to have sliding doors on nest boxes and dens as they too can be used to trap the animal and transport it with minimum fuss.

Devna Arora - Open nest box

Behavioral strategies

The simplest way to encourage desired behavioral responses is by allowing access to natural stimuli. This is often best achieved through a soft release process which may not be feasible for every species or every individual. In all cases, enrichment must be provided in the form of habitat or feeding enrichment whereby the animal gets the opportunity to express its natural movements and behaviors and do what it would do in nature.

Devna Arora - Feeding enrichment

Some common ways of providing enrichment include hiding food around the enclosure to encourage a search, offering live prey (where legalities permit and done in a humane manner), giving whole instead of shelled nuts, placing food puzzles, offering other natural toys, etc. Arboreal animals must have lots of climbing branches while semi-aquatic species must have access to ponds. Such strategies are extremely useful for both permanently and temporarily captive animals as it keeps the mind occupied and prevents stereotypic behaviors that results from boredom.

Wherever possible, for group–living species in particular, animals must be housed together and encouraged to interact with each other. They are more likely express their natural behaviors in the others presence – this not only enhances their communications and interactions within the groups but also helps in the establishment of a hierarchy and the expression of other social behaviors within the group. It has an added benefit of increasing inter-dependence and attachment with members of the same species and discourages excessive bonding with their human caretakers.

For more information, please refer to our pages onCareNutritional Basics for feeding enrichment, and Housing for enrichment in enclosures.

Avoidance of predators

Although all wild animals have an innate recognition of danger and will instinctively respond to predators, some responses are only learned through experience. Many young animals will simply copy the responses of their parents to certain animals and situations, and learn to associate a certain stimuli with a negative response. Often, they will also emulate your response. If you react negatively to a certain situation or animal in the young one’s presence, don’t be surprised to hear an alarm call the next time the little animal finds itself in the same situation.

‘Predator avoidance’ may be crucial for the young and is certainly not an easy one to tackle. This is perhaps one of the main reasons a soft release process is used for young animals as it gives them adequate time to view dangers from a safe distance. Predator puppets, shadows, smells, etc. are also commonly used to stimulate behavioral responses.

A primary point of consideration here is preventing habituation to predators. Animals in captivity are often housed in unnatural proximity to other animals. Over time, they get habituated and stop responding to the smells, sounds, sights and movements around them. Once an animal is habituated to a predator or any other animal that would cause it harm, it is unlikely to flee. Survival of such animals is greatly lowered and they must never be allowed to get habituated to such stimuli.

Hunting

A predatory animal must not only have the ability to catch prey, but it must be able to do so repeatedly and consistently. Although a young predator will instinctively stalk and pounce on anything that moves, being able to hunt successfully requires a lot of learning and experience. For ease of differentiation, hunting behavior can be divided into two responses:
1. Stalking and Pouncing and
2. Hunting, or rather, successful striking and hunting.

Stalking and pouncing are instinctive behaviors – all baby animals, even small puppies and kittens, start stalking and pouncing on objects by the time they are 6-8 weeks old. They are yet incapable of successfully striking at an object or prey. Over time, through play behaviors and many unsuccessful hunting attempts, the animal learns to pursue its target meaningfully. As it grows and matures, it learns to strike purposefully (rather than playfully) and begins to hunt. Such practice and play behavior is vital for predators under rehabilitation.

Hunting isn’t an easy process – just as predators are designed to hunt, prey are designed to escape. It takes great skill, coordination and reflexes for a predator to catch an animal for food. All predatory animals must be given extensive practice with various stimuli before they are considered for release. Hunting practice must preferably be with live prey (where legalities permit) during the last stage of rehabilitation.

Depending upon the needs of the species, hunting here could signify the pursuit of:
1. Aerial insects
2. Terrestrial insects
3. Fish and other crustaceans
4. Small mammals, birds and invertebrates
5. Large mammals

Contrary to mammals or birds, reptiles rarely, if at all, provide parental care after birth. At most, the young may obtain security due to the parent’s presence, but there are no known instances where reptilian parents actually teach their offspring how to hunt. Any rescued individuals may thus, after ascertaining good health of each individual, be allowed to disperse naturally without much fuss. It is only in exceptional instances, where a reptile has been accustomed to feeding in captivity that it may need to go through a rigorous rehabilitation process to ensure its ability to hunt and sustain itself. Of prime concern here is therefore the habitat selected for release as it must provide the animal with the opportunity to thrive.

Avoid imprinting and habituation

Inappropriate imprinting and habituation are perhaps the two most detrimental factors to the process of rehabilitation and every care must be taken to avoid either.

Imprinting

Imprinting is a form of learning in which a young animal fixes its attention on the first living being that it meaningfully interacts with. It is a behavior by which young animals are imprinted on by their parents and it only occurs at a specific period of an animal’s life – at a young age during infancy. Imprinting is vital in baby animals as it is behavior by which young animals emulate their parents and follow them around.

Imprinting behavior has long been documented and extremely well studied in waterfowl. A classic example of the expression of imprinting behavior is that of baby ducks following the first moving object. Even cartoons like Tom ‘n Jerry and popular movies like Winged Migration, Fly Away Home, etc. show good examples of imprinting.

As beneficial as imprinting is when baby animals imprint on their own parents in nature, this tends to cause some setbacks when baby animals are raised by other species, i.e. us rehabilitators. Although this isn’t seen as often, babies that strongly imprint on us are likely to show humanized characteristics and other behaviors not normally seen in nature – this is obviously detrimental for their survival. If any animal is found to be significantly imprinted by an inappropriate species, the first step in rehabilitation would be to break the undesirable contact and begin to offset the effects of imprinting and where beneficial, offer another suitable object for imprinting instead. Under most instances, once given the opportunity the young animal will soon learn to follow individuals (and behaviors) of its own species. As the baby grows, it will also begin to exhibit species-specific behaviors – such behaviors must be encouraged and enhanced.

Where feasible, babies can be given to foster parents of the same or similar species. Although this can easily be achieved in domestic species, it is rather difficult to find a foster parent of the same species for a wild animal. A significant benefit of rearing young by foster parents of the same species is that the young get imprinted by desirable species and learn beneficial behavior behaviors faster. They also learn to recognize individuals of their own species as their primary caregivers and which keeps them from getting attached to humans.

Habituation

Habituation is a simple form for learning in which, after repeated exposure to a stimulus that doesn’t threaten them directly, the animal stops responding to it. Unlike imprinting, habituation can happen at any age or stage of an animal’s life. This practice is commonly used to the study the behavior of elusive animals in the wild. In the first phase of study, the animals are habituated to the researcher’s presence (often by means of positive reinforcement). By means of slowly and constantly exposing yourself to the study animals, you prove to them that your presence is of no harm to them. Once the animals accept the researcher’s presence and demonstrate natural behaviors (without any inhibition) in their presence, the reinforcement stops and all energy is concentrated on the study of the subjects.

The biggest threat posed by habituation is that the animals lose their instinctive fear of all human beings. Such a trait is undesirable in a wild animal as it may run into people that mean it harm. Poaching is currently one of the biggest threats to any wild animal and an animal that doesn’t naturally flee at the sight of humans is obviously under threat. Another disadvantage of habituation is that animals may also learn to recognize human beings as caregivers and may resort to begging when difficult situations arise. Often, animals learn to become independent and self-sufficient in time, yet, it is best for their survival that they be habituated to the minimum.

Minimal contact

As a rule, we follow a practice of minimal or no contact with any wild animal that is to be released. Although this may be difficult to achieve it is may not always be impossible. Handling, in such cases is done by remote means where a person doesn’t come in direct contact with the animal. Although it takes a lot more effort to achieve this, it is often most beneficial for the animal in concern.

Lifetime care

 

Despite our best efforts, there may always be some animals that cannot be released back into the wild. This is mostly likely due to obvious physical inabilities or behavioral maladaptations. Although the purpose of rehabilitation is to address such gaps, sometimes it may not be achieved to our expectations. Releasing such animals will only result in death, defeating the very purpose of rescue.

Often, many behaviors can be relearned and refined to benefit the individual. When all else fails, such individuals may be considered as candidates for permanent placement in care centers. They might just be better suited to a life in captivity and might make ideal candidates for breeding or educational programmes, or as zoo exhibits and species ambassadors. Although rare, some rescued animals are even known to have stayed on and become ‘foster parents’ in turn! Do not be dismayed by the animal’s lack of release potential as the possibilities are limitless.

Useful links

Dept. of Environment and Conservation (2008) Minimum standards for wildlife rehabilitation in Western Australia
http://www.dec.wa.gov.au/content/view/3576/341/
Download pdf

Miller, E. (2000) Minimum standards for wildlife rehabilitation
http://www.nwrawildlife.org/sites/default/files/MinimumStandards3rd
Edition.pdf
Download pdf

Plowman, A. (undated) A keeper’s guide to evaluating environmental enrichment
http://www.biaza.org.uk/uploads/Committees/RC/Research%20
Guidelines/EvaluatEnrichment.pdf
Download pdf

RSPCA (2010) Establishment standards for wildlife rehabilitation
http://www.rspca.org.uk/ImageLocator/LocateAsset?asset=document&assetId=1232725417924&mode=prd
Download pdf

Resende et al. (2009) The influence of feeding enrichment on the behavior of small felids (Carnivora: Felidae) in captivity
http://www.scielo.br/pdf/zool/v26n4/v26n4a03.pdf

Thompson, P. (undated) Wildlife rehabilitation manual
http://wdfw.wa.gov/conservation/health/rehabilitation/rehab_manual.pdf
Download pdf