Behavioral enrichment also called environmental enrichment, is an 'animal husbandry principle that seeks to enhance the quality of captive animal care by identifying and providing the environmental stimuli necessary for optimal psychological and physiological wellbeing'. The goal of environmental enrichment is to improve or maintain an animal's physical and psychological health by increasing range or number of species-specific behaviors, increasing positive utilization of the captive environment, preventing or reducing the frequency of abnormal behaviors such as stereotypical behaviors, and increasing the individual's ability to cope with captive challenges. In principle, enrichment can be beneficial to any relatively intelligent animal, including mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s, bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s, and even octopus

Octopus

The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...

es.

Environmental enrichment may be offered to any animal in captivity, including:

• Captive
  Captivity (animal)
  Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either domesticated animals or wild animals. This may include for example farms, private homes and zoos...
  
   animals in zoos and related institutions.
• Animals in sanctuaries
  Animal sanctuary
  An animal sanctuary is a facility where animals are brought to live and be protected for the rest of their lives. Unlike animal shelters, sanctuaries do not seek to place animals with individuals or groups, instead maintaining each animal until his or her natural death...
  
  .
• Animals used for research
  Animal testing
  Animal testing, also known as animal experimentation, animal research, and in vivo testing, is the use of non-human animals in experiments. Worldwide it is estimated that the number of vertebrate animals—from zebrafish to non-human primates—ranges from the tens of millions to more than 100 million...
  
  
• Animals used for companionship
  Pet
  A pet is a household animal kept for companionship and a person's enjoyment, as opposed to wild animals or to livestock, laboratory animals, working animals or sport animals, which are kept for economic or productive reasons. The most popular pets are noted for their loyal or playful...
  
  , e.g. dogs, cats, rabbits, etc.

Types of enrichment

Any novel stimulus which evokes an animal's interest can be considered enriching, including natural and artificial objects, scents, novel foods, and different methods of preparing foods (for example, frozen in ice). Most enrichment stimulus can be divided into six groups:

• Sensory
  Sensory system
  A sensory system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory receptors, neural pathways, and parts of the brain involved in sensory perception. Commonly recognized sensory systems are those for vision, hearing, somatic...
  
  , this category stimulates animals' senses: visual, olfactory, auditory, tactile, and taste.
• Feeding, this is how keepers make feeding time fun and challenging. Different methods of food presentation encourage animals to think and work for their food as they would in the wild.
• Manipulative Toys, these are items that can be manipulated in some way via hands, feet, tail, horns, head, mouth etc. simply for investigation and exploratory play.
• Environmental
  Natural environment
  The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....
  
  , this category enables the keeper to enhance the animals' zoo habitat with opportunities that change or add complexity to the environment.
• Social, the opportunities to interact with other animals.
• Training
  Animal training
  Animal training refers to teaching animals specific responses to specific conditions or stimuli. Training may be for the purpose of companionship, detection, protection, entertainment or all of the above....
  
  , training animals with positive reinforcement.

Puzzle

Puzzle

A puzzle is a problem or enigma that tests the ingenuity of the solver. In a basic puzzle, one is intended to put together pieces in a logical way in order to come up with the desired solution...

s that require an animal to solve simple problems in order to access food or other rewards are considered enrichment.
Additionally food collecting and/or gathering contributes to behavioral enrichment and provides occupation. Quite elaborate systems of food presentation (dead rats) have been developed (e.g. in Switzerland for wild cats), where computer programmed various mechanic devices allow the animals in the enclosure to search for prey as in their natural environment.
An animal's environment may also be enriched by the presence of other animals of the same or different species. A stimulus can be considered enriching even if the animal's reaction to it is negative, such as with unpleasant scents, although stimuli that evoke extreme stress or fear should be avoided, as well as stimuli that can be harmful to the animal. Enrichment can also be auditory which may include animal sounds and music.

Many people also believe that a behavior modification program (animal training

Animal training

Animal training refers to teaching animals specific responses to specific conditions or stimuli. Training may be for the purpose of companionship, detection, protection, entertainment or all of the above....

) can also be enriching to a captive animal.
Also the use of behavioral training, as another method of behavioral enrichment, has often contributed to the animals well-being as well as allowed zoos to improve dramatically their ability to care for animals, while reducing animal stress and increasing safety for both keeper and animal during care procedures.

Enclosures in modern zoos are often designed with enrichment in mind. For example, the Denver Zoo

Denver Zoo

The Denver Zoo is an facility located in City Park of Denver, Colorado, USA. Founded in 1896, it is owned by the City and County of Denver and funded in part by the Scientific and Cultural Facilities District . It was the most popular paid attraction in the Denver metropolitan area in 2005.The...

's exhibit Predator Ridge allows different African carnivore

Carnivora

The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...

 species to rotate among several enclosures, providing the animals with a larger environment and exposing them to each others' scents.

United States

The 1985 amendments to the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 Animal Welfare Act amendments directed the Secretary of Agriculture

United States Secretary of Agriculture

The United States Secretary of Agriculture is the head of the United States Department of Agriculture. The current secretary is Tom Vilsack, who was confirmed by the U.S. Senate on 20 January 2009. The position carries similar responsibilities to those of agriculture ministers in other...

 to establish regulations to provide an adequate physical environment to promote the psychological well-being of primate

Primate

A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...

s and exercise for dog

Dog

The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...

s. Subsequent standards for nonhuman primate environmental enhancement (including provisions for social grouping and environmental enrichment) are included under Section 3.81 in the Animal Welfare Regulations (9 CFR

Code of Federal Regulations

The Code of Federal Regulations is the codification of the general and permanent rules and regulations published in the Federal Register by the executive departments and agencies of the Federal Government of the United States.The CFR is published by the Office of the Federal Register, an agency...

). Concepts relating to behavioral needs and environmental enrichment are also incorporated into the standards for marine, flying, and aquatic mammals.

External links

• Laboratory Animal Refinement Database
• Animals in Laboratories (awionline.org)
• 3R Research Foundation Switzerland (forschung3R.ch)
• Animal Welfare Information Center (nal.usda.gov)
• The Shape of Enrichment selected articles on enrichment for zoo animals.
• Environmental Enrichment for Pet Cats (ASPCA)
• Environmental Enrichment for Pet Dogs(ASPCA)
• Environmental Enrichment for Horses(ASPCA)