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Zoo and wildlife terms, explained
What does “endangered” actually mean? What is AZA accreditation, or a Species Survival Plan? Plain-English answers to the words you see on zoo signs, animal pages and conservation news.
Conservation status
How scientists rate the risk that a species will go extinct, from Least Concern to Extinct in the Wild.
- Critically EndangeredCritically Endangered (CR) is the IUCN Red List category for species facing an extremely high risk of extinction in the wild. It is the most severe of the three 'threatened' categories, one step below Extinct in the Wild.
- Data DeficientData Deficient (DD) is the IUCN Red List label for species where there isn't enough information on population or distribution to judge their extinction risk. It is not a threat category, and a Data Deficient species could turn out to be anywhere from Least Concern to Critically Endangered.
- EndangeredEndangered (EN) is an IUCN Red List category for species facing a very high risk of extinction in the wild. It is the middle of the three 'threatened' categories, above Vulnerable and below Critically Endangered.
- Extinct in the WildExtinct in the Wild (EW) is the IUCN Red List category for species that survive only in human care, in cultivation, or as a naturalized population well outside their historic range. It is the last category before Extinct.
- IUCN Red ListThe IUCN Red List of Threatened Species is the world's most widely used inventory of extinction risk. Run by the International Union for Conservation of Nature, it sorts assessed species into categories from Least Concern to Extinct using measurable scientific criteria.
- Least ConcernLeast Concern (LC) is the IUCN Red List category for species that have been assessed and do not qualify as threatened or Near Threatened. These species are usually widespread and abundant, although some still have declining populations.
- Near ThreatenedNear Threatened (NT) is the IUCN Red List category for species that do not currently qualify as threatened but are close to qualifying, or are likely to qualify in the near future. It sits between Least Concern and Vulnerable.
- VulnerableVulnerable (VU) is an IUCN Red List category for species facing a high risk of extinction in the wild. It is the lowest of the three 'threatened' categories, above Near Threatened and below Endangered.
Accreditation and the law
Who inspects zoos and sanctuaries, and the U.S. and international laws that protect animals.
- Animal Welfare ActThe Animal Welfare Act is the main U.S. federal law setting minimum standards of care for animals that are exhibited to the public, sold as pets, used in research or transported commercially. It is enforced by the USDA, which licenses zoos and other animal exhibitors and inspects them.
- AZA accreditationAZA accreditation is a voluntary, independent review by the Association of Zoos and Aquariums that confirms a zoo or aquarium meets professional standards for animal welfare, veterinary care, conservation, education and safety. Accredited facilities are re-inspected every five years.
- CITESCITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, is an international treaty that controls cross-border trade in wild animals and plants so it doesn't threaten their survival. Listed species fall into three Appendices with different levels of protection.
- Endangered Species ActThe Endangered Species Act (ESA) is a U.S. law, signed in 1973, that protects plants and animals listed as endangered or threatened and aims to recover them. It is administered by the U.S. Fish and Wildlife Service and NOAA's National Marine Fisheries Service.
- GFAS accreditationGFAS accreditation is a certification from the Global Federation of Animal Sanctuaries, a nonprofit founded in 2007, showing that a sanctuary or rescue center meets its standards for humane care, with no breeding, no commercial trade and no public contact with wildlife.
- ZAA accreditationZAA accreditation is a voluntary certification from the Zoological Association of America, a nonprofit formed in 2005, showing that a zoo, aquarium or educational animal facility has passed ZAA's application, site inspection and committee review. Facilities repeat the full process every five years.
Conservation in zoos
How zoos breed endangered species, manage populations and return animals to the wild.
- AZA SAFEAZA SAFE: Saving Animals From Extinction is a program of the Association of Zoos and Aquariums that pools the work of many accredited zoos and aquariums on specific at-risk species, with a focus on conservation results in the wild.
- Ex situ conservationEx situ conservation means protecting a species outside its natural habitat, for example by breeding it in zoos, aquariums or botanical gardens, or by storing seeds and frozen cells. In situ conservation is the opposite: protecting species where they live in the wild.
- Insurance populationAn insurance population is a group of animals kept in human care as a backup for a species that is at risk in the wild. If the wild population crashes, the insurance population keeps the species alive and can supply animals for reintroduction.
- ReintroductionReintroduction is the deliberate release of animals into part of their native range where the species has disappeared, with the goal of establishing a healthy, self-sustaining wild population. Released animals can come from zoos, breeding centers or other wild populations.
- Species Survival Plan (SSP)A Species Survival Plan (SSP) is a cooperative breeding program run by the Association of Zoos and Aquariums (AZA). It manages one species across many zoos and aquariums as a single population, recommending which animals breed and which move so the population stays healthy and genetically diverse.
- StudbookA studbook is the official record of every animal in a managed zoo population, tracking each one's parents, birth, moves between institutions and death. Population managers use it to plan breeding that keeps the population healthy and genetically diverse.
Animal care
The day-to-day science of keeping animals healthy, active and well.
- Animal ambassadorAn animal ambassador, or ambassador animal, is a zoo or aquarium animal that takes part in education programs, such as keeper talks, classroom visits and up-close encounters. Many are rescued animals that cannot be released to the wild.
- Animal enrichmentAnimal enrichment is anything zookeepers add to an animal's surroundings or routine to encourage natural behaviors, such as foraging, exploring and problem-solving. It includes puzzle feeders, new scents, toys, habitat changes and social time, and it is a core part of good animal welfare.
- Animal husbandryIn zoos, animal husbandry is the day-to-day care and management of animals: feeding and nutrition, cleaning and habitat upkeep, health monitoring, record keeping and training. It covers everything keepers and veterinarians do to keep each animal healthy.
- Animal sanctuaryAn animal sanctuary is a facility that gives rescued, retired or surrendered animals humane care, usually for the rest of their lives, without breeding, selling or trading them or using them for entertainment. True sanctuaries don't allow public contact with wild animals.
- Mixed-species exhibitA mixed-species exhibit is a zoo habitat where two or more species live together, such as giraffes, zebras and antelope on an African savanna, or many bird species in one aviary. Done well, it creates a larger, more natural and more stimulating home for the animals.
- Wildlife rehabilitationWildlife rehabilitation is the care of injured, sick or orphaned wild animals by trained, permitted rehabilitators, with the goal of releasing them back into the wild. Animals that recover but can't survive on their own sometimes become educational animal ambassadors.
Animal behavior
When and how animals are active, and what that means for when to visit.
- CrepuscularA crepuscular animal is one that is most active during twilight, around dawn and dusk. Deer, rabbits, bobcats, chinchillas and red pandas are examples, and many animals casually called nocturnal are actually crepuscular.
- DiurnalA diurnal animal is one that is active mainly during the day and sleeps or rests at night. Most primates, including humans, are diurnal, as are most birds and many reptiles.
- NocturnalA nocturnal animal is one that is active mainly at night and sleeps or rests during the day. Owls, raccoons, opossums, most bats and many desert animals are nocturnal.