Animals

Greyfriars Bobby — the loyal Skye terrier of Edinburgh Greyfriars Bobby An encyclopedic overview of Greyfriars Bobby, the 19th‑century Skye terrier famed for guarding his master's grave in Edinburgh, and the memorials, cultural legacy and historical di…

Greyhound — sighthound breed known for speed and slender build Greyhound Greyhounds are an ancient sighthound breed noted for speed, a lean athletic body, and a calm temperament. They have been used for coursing and racing and are the focus of modern we…

Greylag goose (Anser anser): appearance, behaviour, and human connections Greylag goose A large grey goose native to Europe and Asia. Covers identification, habitat, migration, breeding, domestication, and conservation of Anser anser.

Ground beetle (Carabidae): overview, traits, ecology and importance Ground beetle Ground beetles (Carabidae) are a large, cosmopolitan family of mostly predatory beetles with over 40,000 described species; they occupy terrestrial habitats and play key roles in e…

Ground sloth — extinct large sloths of the Americas Ground sloth Extinct group of large, often heavy-built sloths (Xenarthra) that evolved in South America, spread into North America and the Caribbean, and mostly disappeared in the late Quaterna…

Ground squirrel Ground squirrels are terrestrial members of the squirrel family, including marmots; they build burrows, form social colonies, hibernate in cold climates, and play notable ecologica…

Groundhog (Marmota monax): North American burrowing marmot Groundhog A compact encyclopedia entry on the groundhog (Marmota monax): its appearance, burrowing behavior, diet, reproduction, predators, hibernation, and cultural role such as Groundhog D…

Grouper (Epinephelinae): reef predators, fisheries, and biology Grouper Large, stout-bodied reef and coastal fishes of the subfamily Epinephelinae valued by fisheries. Overview of taxonomy, anatomy, behavior, human uses and conservation issues.

Grouse: terrestrial game birds of the Galliformes Grouse Grouse are ground-dwelling game birds in the order Galliformes, with cryptic plumage, feathered legs and seasonal behaviours; important ecologically and as game species across temp…

Gruiformes — crane-like birds: overview, evolution and ecology Gruiformes Order of primarily wetland-associated birds that includes cranes and rails; historically diverse with a deep fossil record, complex classification, varied ecology, and notable cons…

Grus — genus of cranes Grus Grus is a genus of large, long-legged birds in the crane family. This article summarizes their appearance, behaviour, taxonomy, distribution, cultural importance and conservation.

Grylloblattidae — ice crawlers, cold-adapted wingless insects Grylloblattidae Grylloblattidae are small, wingless insects adapted to cold alpine and subarctic habitats. Nocturnal detritivores with long antennae and cerci, placed in Grylloblattodea and closel…

Guadalupe bass (Micropterus treculii) Guadalupe bass A freshwater black bass native to central Texas rivers, prized by anglers and subject to habitat and genetic conservation concerns. Overview, identification, habitat, life history,…

Guam kingfisher (Todiramphus cinnamominus) Guam kingfisher A small, brightly colored kingfisher native to Guam, now surviving only in captivity; notable for its rufous body, blue wings and long-term conservation efforts.

Guam rail The Guam rail (Hypotaenidia owstoni), known locally as ko'ko', is a flightless bird endemic to Guam and extinct in the wild, with ongoing conservation breeding efforts.

Guanaco (Lama guanicoe) Guanaco Wild camelid native to South America; ancestor of the domestic llama. Lives in Andes and Patagonian steppes, forms small herds, valued for its wool; conservation status varies regi…

Guard dog: roles, types, training, and legal considerations Guard dog Comprehensive overview of guard dogs: definition, how they differ from watchdogs, common roles and breeds, training and welfare, livestock guardians, equipment, and legal and safet…

Guide dog (seeing-eye dog) Guide dog A guide dog is a specially trained dog that helps people with visual impairment travel safely and independently. This article explains training, roles, history, limitations, and le…

Guinea Pig (Cavia porcellus): Biology, Origins, and Role as Pets and Research Animals Guinea pig A concise overview of the domestic guinea pig (Cavia porcellus): classification, physical traits, origins in the Andes, care, and scientific and cultural importance.

Guineafowl: African ground birds of the family Numididae Guineafowl Guineafowl are ground-dwelling African birds (family Numididae) with spotted plumage and helmet-like casques. They have an ancient galliform lineage and include wild species and th…

Gun dog (gundog): roles, types, and training Gun dog Overview of gun dogs (gundogs): roles, principal types, history, common breeds, training basics, modern working roles, selection, care, and ethical considerations for hunters and h…

Guppy (Poecilia reticulata): overview, biology, care and significance Guppy Small colorful livebearing freshwater fish widely kept in aquariums and studied in biology; notable for sexual dimorphism, rapid breeding, and many domesticated color strains.

Gymnopis syntrema: Central American caecilian Gymnopis syntrema Gymnopis syntrema is a limbless, subterranean amphibian of the family Caeciliidae found in Belize, Guatemala and Honduras; secretive forest-dweller threatened mainly by habitat los…

Gymnotiformes — Neotropical electric fishes Gymnotiformes Gymnotiformes are a group of freshwater, primarily South American fishes that generate electric fields for sensing, communication and, in some species, powerful predation or defens…

Gyposaurus (early Jurassic prosauropod) Gyposaurus Gyposaurus is a historically named genus of small prosauropod dinosaurs from the Early Jurassic of South Africa and China. Most specimens are fragmentary and often considered juven…

Haast's eagle — the giant apex raptor of New Zealand Haast's eagle Haast's eagle (Harpagornis/Hieraaetus moorei) was a very large, forest-adapted raptor endemic to New Zealand’s South Island that preyed on moa and became extinct after human arriva…

Haddock (Melanogrammus aeglefinus) Haddock North Atlantic cod-family fish prized for its white, flaky flesh and commercial importance; identifiable by a dark lateral blotch and commonly used fresh, smoked or fried.

Hadrosaur (Hadrosauridae) — the duck‑billed herbivorous dinosaurs Hadrosaur Hadrosaurs were diverse, common Late Cretaceous duck‑billed herbivores known for tooth batteries, toothless beaks, and, in some kinds, hollow crests; fossils found across North Ame…

Hadrosaurus (Hadrosaurus foulkii) Hadrosaurus Hadrosaurus foulkii is an early-discovered duck-billed dinosaur from the Upper Cretaceous of eastern North America, notable for its historical mounted skeleton and for taxonomic un…

Haflinger: small mountain horse known for chestnut coat and versatility Haflinger Haflinger, a compact mountain-bred horse from the Tyrol region, is known for its chestnut coat, flaxen mane, sure-footedness and versatile use in riding, driving, therapy and light…

Hagfish: jawless marine craniates and their biology Hagfish Hagfish are eel-like, jawless marine craniates notable for a cartilaginous skull, slime defense, scavenging habits, and a debated position in vertebrate evolution.

Halibut: Atlantic and Pacific flatfish — biology, fisheries, and uses Halibut Halibut are large flatfish of the genus Hippoglossus (Atlantic and Pacific). This article covers their biology, habitats, fisheries, culinary uses and conservation, plus distinguis…

Hallopus — a small prehistoric crocodylomorph once misidentified as a dinosaur Hallopus Hallopus is a small, lightly built prehistoric crocodylomorph. Named by O. C. Marsh in 1881 and once classified as a dinosaur, it is now interpreted as an early crocodylomorph with…

Hallucigenia — Cambrian lobopodian genus Hallucigenia Hallucigenia is an extinct genus of small, soft-bodied Cambrian animals known from Burgess Shale and Chengjiang fossils; once baffling, it is now seen as a lobopodian related to ea…

Halteres — the gyroscopic balancing organs of flies Halteres Halteres are small, knobbed organs in flies derived from hind wings; they oscillate during flight and act as gyroscopic sensors that detect body rotations and stabilize maneuvering…

Hamadryas baboon (Papio hamadryas): appearance, behavior, and significance Hamadryas baboon A northern African and Arabian baboon species, Papio hamadryas is known for sexual dimorphism, complex social systems and historic cultural importance in ancient Egypt.

Hamish McHamish — the St Andrews celebrity ginger cat Hamish McHamish Hamish McHamish (1999–2014) was a famous ginger cat from St Andrews, Scotland; a local icon, subject of a book, and an online celebrity owned by Marianne Baird.

Hammerhead shark A concise overview of hammerhead sharks: their distinctive cephalofoil, taxonomy, habitat, behavior, conservation issues, and notable biological adaptations.

Hamster: biology, behavior, and relationship with people Hamster Comprehensive overview of hamsters: classification, anatomy, behavior, natural history, common species, keeping as pets, husbandry basics, role in research, and conservation consid…

Harbor seal (Phoca vitulina): appearance, range, behavior and conservation Harbor seal Harbor seal (Phoca vitulina) is a widely distributed true seal of northern coastal waters. This article covers identification, habitat, feeding, reproduction, lifespan and conserva…

Hare (Lepus): biology, behavior, and relationship to humans Hare Hares (genus Lepus) are fast, long‑eared mammals in the family Leporidae. This article explains their anatomy, life cycle, habitat, diet, differences from rabbits, and interactions…

Harlequin duck (Histrionicus histrionicus) Harlequin duck A compact sea duck notable for the male's bold, contrasting plumage and the female's subdued colors; breeds on fast mountain streams and winters along rocky coasts across the North…

Harp seal (Pagophilus groenlandicus) Harp seal A northern Atlantic and Arctic earless seal known for its harp-shaped back marking, ice-dependent breeding on pack ice, and importance in marine ecosystems and human history.

Harpy eagle (Harpia harpyja) Harpy eagle Large Neotropical forest raptor known for its size, crest and massive talons. Lives in lowland rainforests of Central and South America; faces habitat loss, persecution and fragmen…

Harrier (bird): low-flying hawks of open country Harrier Harriers are slender, ground-hunting raptors (genus Circus) that forage by flying low over fields and marshes. Juveniles and some females are often called ring-tails.

Hawk (birds of prey) Hawk Hawks are medium to large birds of prey known for keen eyesight, hooked beaks and sharp talons. The term covers 'true' Accipitrinae hawks and, in broader use, several raptor groups…

Hazel dormouse (Muscardinus avellanarius) Hazel dormouse Small nocturnal arboreal rodent of Europe and Asia Minor, noted for long hibernation, dependence on hedgerows and woodland understorey, and conservation concern where habitats are…

Hearing dog: assistance animals for the deaf and hard of hearing Hearing dog A hearing dog is a trained assistance animal that alerts deaf or hard-of-hearing people to important sounds such as alarms, doorbells, phones and baby cries and leads them to the s…