Animals

Cigar (American Thoroughbred racehorse) Cigar (horse) Cigar was an American Thoroughbred racehorse famed for a 16-race winning streak in 1995–1996, record earnings at retirement, induction into the Racing Hall of Fame, and his death a…

Cinereous vulture (Aegypius monachus) Cinereous vulture Large Old World vulture found across Eurasia; a chiefly scavenging bird with dark plumage, important ecological role, distinct taxonomy, and conservation concerns in parts of its r…

Cinnabar moth (Tyria jacobaeae) Cinnabar moth A brightly colored day-flying moth native to Europe and Asia, used in many regions as a biocontrol agent against ragwort; notable for its red-and-black wings and toxic, striped cat…

Cirrina — finned deep-sea octopuses Cirrina Cirrina are a suborder of octopuses characterized by paired fins, cirri on their arms, and a small internal shell; they are adapted to deep-sea life and include the so-called dumbo…

Citipati — Late Cretaceous oviraptorid dinosaur Citipati Citipati is a genus of birdlike oviraptorid theropod from the Late Cretaceous of Mongolia, known for well-preserved brooding specimens and the type species Citipati osmolskae (desc…

Cladocera (water fleas): overview, form, life cycle and ecological role Cladocera Cladocera, or water fleas, are small freshwater branchiopod crustaceans known for jerky swimming, cyclical parthenogenesis, ephippial resting eggs, and central roles in lake and po…

Clam: biology, habitat, culinary uses, and ecological role Clam Clams are bivalve molluscs found in marine and freshwater environments. This article summarizes their anatomy, life cycle, habitats, ecological importance, human uses and differenc…

Classification Overview of classification: principles, history, major methods, common distinctions and practical applications across science, information systems and machine learning.

Claw A claw is a curved, often sharp appendage at the tip of a digit in many vertebrates and some invertebrates, used for grasping, digging, defense and other functions; made chiefly of…

Cleaner fish: mutualistic cleaners of reefs and freshwater habitats Cleaner fish Cleaner fish are species that remove parasites and dead tissue from other animals, forming mutualistic relationships important for fish health and ecosystem balance in marine and f…

Cleaner shrimp: reef symbionts that remove parasites from fish Cleaner shrimp General overview of cleaner shrimp: their behavior, ecology, common species, role at reef cleaning stations, use in aquaria, and distinctions from cleaner fish and other symbionts.

Clever Hans — the horse that revealed the observer-expectancy effect Clever Hans Clever Hans was a horse in early 20th-century Germany that seemed to solve arithmetic but actually responded to subtle human cues, a finding that reshaped experimental controls and…

Click beetle (Elateridae): appearance, behavior and human relevance Click beetle Click beetles (family Elateridae) are elongated beetles known for an audible snapping jump. This article covers their form, the clicking mechanism, life cycle, ecology, agricultura…

Climacoceratidae — extinct giraffoid artiodactyls of the Miocene Climacoceratidae Climacoceratidae is an extinct family of Miocene African artiodactyls related to giraffes, known for distinct cranial appendages (ossicones) and debated placement near Giraffidae w…

Clouded leopard (Neofelis nebulosa): description, behavior, and conservation Clouded leopard Medium-sized Asian forest cat with distinctive 'cloud' markings. Arboreal hunter found from the Himalayas through Southeast Asia to China; vulnerable due to habitat loss and poachi…

Clownfish: biology, habitat, symbiosis, and human interactions Clownfish Overview of clownfish: appearance, taxonomy, Indo‑Pacific reef distribution, mutualism with sea anemones, social and reproductive biology, aquarium use, and conservation considerat…

Clupeidae: herrings, shads, sardines and related fishes Clupeidae Clupeidae is a family of small to medium pelagic teleost fishes — herrings, shads, sardines, hilsa and menhadens — that form large schools and support major commercial and ecologic…

Cnidaria: overview of jellyfish, corals, sea anemones and related animals Cnidaria Cnidaria is a phylum of mostly marine, simple animals that includes jellyfish, corals and sea anemones, notable for stinging cnidocytes and two basic body forms: polyps and medusae…

Coastal Range newt (Taricha torosa torosa) Coastal Range newt A subspecies of the California newt found in California's coastal ranges and southern coastal counties; notable for its terrestrial habits, toxic skin, and seasonal breeding in pon…

Dog coat Coat (dog) The dog coat is the hair covering a dog's body. This article explains types, structure, functions, seasonal changes, grooming needs, breed differences and how coat condition reflec…

Cobra: hooded venomous snakes, biology, behaviour and human interactions Cobra Cobras are a group of hooded, venomous snakes mainly in the family Elapidae. This article summarizes their appearance, taxonomy, behaviour, venom effects, cultural roles and conser…

Coccinella septempunctata — the seven-spot ladybird Coccinella septempunctata A widespread European ladybird with red elytra and seven black spots; a common aphid predator used in biological control and established beyond its native range.

Cockapoo: origin, traits, care, and commonly seen varieties Cockapoo A Cockapoo is a popular designer dog created by crossing a Cocker Spaniel and a Poodle. This article covers its appearance, temperament, history, breeding types, care needs, health…

Cockatiel (Nymphicus hollandicus): Overview, Care, and Behavior Cockatiel Comprehensive guide to the cockatiel, a small crested parrot from Australia: identification, behaviour, diet, housing, training, health, lifespan and practical care tips for owners…

Cockatoo — overview, characteristics, taxonomy, and human interactions Cockatoo Cockatoos are a group of parrots (family Cacatuidae) native to Australasia, known for expressive crests, strong curved bills, social behaviour, and long associations with people as…

Cocker Spaniel — English and American breeds Cocker Spaniel Two related spaniel breeds developed to hunt woodcock. Covers origins, appearance, temperament, care, health issues, differences between English and American lines, and guidance fo…

Cockle (Cardiidae): small edible marine bivalves Cockle Cockles are small, mostly edible saltwater bivalves in the family Cardiidae. This article covers their anatomy, habitats, behaviour, uses, taxonomy and how they differ from similar…

Cockroach (Blattodea): biology, ecology, and relations with humans Cockroach Overview of cockroaches: classification, appearance, life cycle, ecological roles, common pest species, health impacts and basic control approaches.

Coconut crab (Birgus latro) — the largest land-dwelling crustacean Coconut crab Birgus latro, the coconut crab, is a large terrestrial crustacean of Indo‑Pacific islands. This article explains its biology, behavior, life cycle, human uses and conservation issu…

Atlantic cod (Gadus morhua): biology, fisheries, and uses Cod Overview of the Atlantic cod: its biology, ecological role, history in fisheries, culinary uses, and conservation concerns, with comparisons to related species and notes on process…

Coelacanth: the lobe‑finned 'living fossil' fish Coelacanth Coelacanths are ancient lobe‑finned fishes with a deep fossil record. Rediscovered alive in 1938, two living species persist in deep waters; they are important to studies of verteb…

Coelophysis — an early slender theropod dinosaur Coelophysis Coelophysis was a small, fast, bipedal carnivorous dinosaur from the Late Triassic, best known from large fossil assemblages at Ghost Ranch and important for studying early theropo…

Coelurosauria: the bird‑line theropods and their evolution Coelurosauria Coelurosauria is the clade of theropod dinosaurs more closely related to birds than to carnosaurs, including tyrannosauroids, ornithomimosaurs, maniraptorans and the ancestors of l…

Coelurus — small Late Jurassic hollow-boned theropod Coelurus Coelurus is a small, fragmentarily known genera of hollow-boned theropod from the Late Jurassic Morrison Formation of Wyoming, named by O.C. Marsh in 1879 and notable for its light…

Coenobitidae: family of land hermit crabs Coenobitidae Coenobitidae is the family of terrestrial hermit crabs, including Coenobita and Birgus (the coconut crab). Air-adapted scavengers tied to the sea for breeding; important in coastal…

Coleoidea — the modern shell‑less cephalopods Coleoidea Coleoidea is the cephalopod subgroup that includes octopuses, squids and cuttlefish, distinguished by reduced or internal shells, advanced nervous systems, and diverse marine ecolo…

Collective animal behaviour: principles, examples and significance Collective animal behaviour Study of how and why animals act together in groups, the rules individuals follow, emergent patterns, history of research, ecological importance and applications in science and tec…

Colo — the first gorilla born in captivity and a zoo icon Colo (gorilla) Colo (1956–2017) was the first gorilla born in captivity and the longest-lived known gorilla. Born at the Columbus Zoo, she became a focal point for zoo breeding, conservation, and…

Colobinae: the leaf‑eating Old World monkey subfamily Colobinae Colobinae are a subfamily of Old World monkeys notable for folivorous diets, complex stomachs and diverse African and Asian genera including colobus, langurs and odd‑nosed monkeys.

Coloborhynchus — a toothed, crested pterosaur of the Lower Cretaceous Coloborhynchus Coloborhynchus is a genus of toothed pterosaur known from fragmentary jaws in Lower Cretaceous rocks. It is notable for a distinctive tooth arrangement and a complicated taxonomic…

Colobus: African leaf-eating monkeys of the genus Colobus Colobus Colobus are African monkeys known for reduced thumbs, folivorous diets and complex stomachs. This article covers their traits, habitat, social life, interactions with predators and…

Colorado potato beetle (Leptinotarsa decemlineata) Colorado potato beetle A striped leaf beetle native to North America that is a major pest of potato and other nightshades, notable for its life cycle, wide geographic spread, and frequent evolution of in…

Colossal squid (Mesonychoteuthis hamiltoni) Colossal squid Mesonychoteuthis hamiltoni, the colossal squid, is a large, deep‑sea cephalopod of the Southern Ocean known for great mass, enormous eyes, distinctive tentacular hooks, and a role…

Colourpoint: point coloration in cats and other animals Colourpoint Colourpoint (colorpoint) describes a coat pattern with darker extremities caused by a temperature‑sensitive pigment; used as a breed group name and a descriptive term across specie…

Colubrid (Colubridae): overview, traits and significance Colubrid Colubrids (family Colubridae) form the largest, diverse group of snakes. Most are harmless rear‑fanged species, but a few produce clinically important venom; taxonomy is under acti…

Colugo — the gliding mammals of the order Dermoptera Colugo Colugos are nocturnal, arboreal gliders from Southeast Asia (order Dermoptera). Two living species use an extensive skin membrane to glide between trees and feed mainly on leaves,…

Columbian mammoth (Mammuthus columbi) Columbian mammoth A large Pleistocene proboscidean of North and Central America; adapted to temperate grasslands and woodlands and genetically linked to other mammoth lineages through ancient hybrid…

Columbiformes: pigeons, doves and their relatives Columbiformes Columbiformes are a cosmopolitan order of stout-bodied birds—commonly called pigeons and doves—characterized by a unique crop milk and broad ecological roles across about 300 speci…