Environmental Enrichment

Environmental Enrichment

Environmental enrichment is the process of providing stimulating environments for captive animals in order for them to demonstrate their species-typical behavior, to allow them to exercise control or choice over their environment, and to enhance their well-being.

At Wildlife Reserves Singapore, we believe that environmental enrichment is just as critical to zoo animal welfare as nutrition and veterinary medicine. Enrichment is an integral part of the daily care of the species in our collection.

Enrichment includes the design of stimulating and naturalistic enclosures, the housing of appropriate social groups in zoos, and the introduction of objects, sounds, smells or other stimuli in the animal’s environment.

Goals and Objectives

  • Alleviate boredom and lethargy
  • Improve the physical and mental well-being
  • Reduce stereotypical behaviour (Eg: pacing, swaying)
  • Stimulate and simulate natural behavior
  • Improve animal display
  • Increase the educational value of the exhibits
  • Allow keepers to observe the animal for new and interesting behavioral responses
  • Establish a positive relationship between animal and keeper
  • To be as imaginative and creative towards the enrichments as possible

Types of Enrichment commonly used at WRS

Definition: Relating to the social behaviour of the animal
Types: Permanent or temporary pairings, social groups...

Social enrichment is any interaction; contact or non-contact that covers the following: - contraspecific or mixed species habitats; conspecific or same species habitats, varying group size and composition; and introductions. Keeper and public interactions during feeding sessions or animal encounters are also done regularly. By the process of desensitisation, animals are conditioned to gradually accept food or tactile contact voluntarily, thus allowing keepers to easily conduct more intensive husbandry and veterinary checks.

Top: Human and animal interactions take place during the public feeding and animal contact sessions at the Zoo.
Bottom: Eight harems of Hamadryas baboons constitute a complex social group in their naturalistic exhibit.

Definition: Relating to the dietary habits of the animal
Types: Novel, variety, browse, treats according to frequency, presentation or process...

This encourages foraging activity by varying the novelty and variety of food items as well as frequency and presentation. Food can be hidden, scattered, given as whole pieces or in puzzle feeders. Novel food items, not part of their daily diet, are also given as a surprise treat for the animals.

Top: A giant tortoise having a whole watermelon as novel food enrichment.
Bottom: Macaws extracting treats hidden in pine cones.

Definition: Relating to the physical environment that the animal has been placed
Types: Enclosure size, furniture, vegetation, shelter, substrate, lighting, heating and ventilation...

The physical environment of the habitat is extremely important in maintaining exploratory activity in animals. Features that we look into include the shape, size and complexity of an exhibit, yard or holding area. Enclosure “furniture” includes climbing structures, rest or hide areas, various substrates, pools and other water bodies. Other naturalistic items such as logs and stumps for manipulation or artificial objects such as toys, also form an integral part of the animal’s habitat.

Top: Elephants enjoying their sand bath at Elephants of Asia.
Bottom: Rocks and caves allow reptiles such as the Komodo dragon to bask or retreat into should it need privacy.

Definition: Relating to the five sense of the body
Types: Tactile, taste, olfactory, auditory, sight ...

Animals are stimulated by providing items that evoke all of their senses. Food or water is sometimes mixed with approved flavouring to vary tastes; scents from different herbs, oils, spices or perfume are sprayed onto exhibit furniture to stimulate olfactory exploration. Other sensory enrichment includes tactile or textural sensation, sound and sight.

Top: White rhinos manipulating a log sprayed with vanilla essence.
Bottom: Tigers investigating and exploring aromatic oil and perfume scent trails left by their keepers.

Definition: Relating to how they would react and think in a particular activity
Types: Physical and psychological...

Situations and opportunities that encourage animals to challenge and exercise their cognitive capabilities and take control over their environment. . Examples would be training, puzzle boxes and mechanical devices.

Top: Capuchin monkeys working on getting treats like grapes, sunflower seeds and mealworms hidden inside a PVC pipe in the rattan baskets.
Bottom: Exploration and investigative behaviours are observed in Komodo dragons given a feeder tube filled with prey items.

Tools for Training the Animals at WRS

Our keepers use a wide variety of tools for training the animals. Here are some examples:

Operant Conditioning

A type of learning in which the probability of a behaviour being repeated is increased or decreased by the consequences that follow.

Operant conditioning techniques allow keepers to train and obtain desired behaviours from animals under their care. This is done by gradually shaping the target behaviour and rewarding the animals accordingly. Veterinary and animal management procedures are thus less stressful for the animals, keepers and vets!!

Top left: Separated by metal bars, keepers are able to train white rhinos for voluntary blood draw.
Top right: A training chamber with a built-in weighing scale enables safe training for voluntary blood draw. Keepers can monitor any weight variation in our tigers.
Bottom left: Training for voluntary behaviours allows vets and keepers to conduct routine checks on our chimpanzees without sedation.
Bottom right: Target-training Komodo dragons to enter raceways allow keepers to inspect them at close range.

Left: A Malayan sun bear is trained to “open mouth” to facilitate dental checks.
Center: A female Malayan tapir cooperates during an ultrasound procedure to monitor foetal development.
Right: Target-training a giant tortoise facilitates an easy and stress-free transfer to a new exhibit.

Primary Reinforcer

Something that satisfies the animal’s biological drives and does not require any learning. Examples are food, water and social contact for some animals.

Fruits & Vegetables

Conditioned Reinforcer (Bridge)

A sound or an action that the animal has been conditioned to associate with the primary reinforcer. Overtime, it becomes a reinforcer itself. Keepers in our parks usually use clickers. Other forms of conditioned reinforcer such as the dog whistle, verbal “good” can also be used.



This is a form of reference/guidance which is used for control and/or holds a location or position. A target can be a brightly coloured ball or float at the end of a stick, a coloured marker, or a trainer’s extended finger or fist.

Left: A red ball is used to target a white tiger to a ‘down’ position.
Center: A sun bear learns to target a rope ‘ball’ as a keeper gradually shapes ‘side’ presentation behaviour.
Right: A keeper extends his fist to target a giant tortoise for voluntary weighing in.