Animals

Falkland Islands wolf (warrah) — the extinct canid of the Falklands Falkland Islands wolf Dusicyon australis, the warrah, was the only native land mammal of the Falklands. Observed by Darwin and driven to extinction by human activities; likely reached the islands via a…

Fallow deer (Dama dama): description, behaviour, distribution and human significance Fallow deer Fallow deer (Dama dama) are medium-sized deer native to Eurasia and widely introduced worldwide. Males bear palmated antlers; they occupy mixed woodland and grassland and show seve…

False gharial (Tomistoma schlegelii) — the Malayan gharial False gharial A long‑snouted Southeast Asian crocodilian, Tomistoma schlegelii is a freshwater species with distinctive ecology, uncertain taxonomy and growing conservation concern across its ra…

False killer whale (Pseudorca crassidens) False killer whale Large oceanic dolphin (Pseudorca crassidens) found in tropical and temperate seas worldwide; highly social, cooperative hunters that sometimes interact negatively with fisheries an…

False vampire bat (Megaderma) False vampire bat A small genus of Asian bats called false vampire bats (Megaderma). Two species, large ears and advanced hearing, insectivorous and carnivorous but not blood-feeding; use echolocati…

Fancy rat (domesticated brown rat) Fancy rat A fancy rat is a domesticated brown rat kept as a companion animal. Bred for temperament and appearance, these social, intelligent rodents are kept as pets, show animals, and educa…

Fang: structure, function and diversity of sharp predatory teeth Fang A fang is a long, pointed tooth or appendage used by many animals for grasping, injecting venom, or defense. This article explains types, anatomy, evolution, and ecological roles.

Fat-tailed gerbil (Pachyuromys duprasi) Fat-tailed gerbil A small North African desert rodent with a distinctive fat tail used to store fat. Nocturnal and burrowing, well adapted to arid climates and commonly kept as a pet; lives about 5–…

Fathead minnow (Pimephales promelas): natural history, uses, and distribution Fathead minnow The fathead minnow is a small North American freshwater fish (Pimephales promelas) common in ponds and streams. Widely used as a feeder fish and test organism, it has also been int…

Feathered dinosaur: evolution, evidence, and biological significance Feathered dinosaur An overview of feathered dinosaurs: what they were, how feathers varied, fossil evidence (including Archaeopteryx and Chinese finds), and why feathers changed our view of dinosaur…

Feathertail glider (Acrobates pygmaeus) Feathertail glider A tiny Australian marsupial and the world’s smallest gliding mammal, the feathertail glider uses a feather-like tail and a small patagium to glide between trees while foraging for…

Felidae: The Cat Family — traits, evolution, and role in nature Felidae Felidae is the biological family of cats, a group of obligate carnivorous mammals including wild species and the domestic cat; they share distinctive anatomy, a fossil history sinc…

Feliformia: the cat-like carnivores Feliformia Feliformia is the clade of carnivoran mammals that are more cat-like in anatomy and behavior, including cats, hyenas, civets and related families; it contrasts with the dog-like Ca…

Felinae: the small-cat subfamily — traits, evolution, and notable species Felinae Felinae is the subfamily of Felidae that comprises most small to medium-sized cats, including domestic cats, lynxes, cougars and the cheetah; this article covers their traits, evol…

Felis — the genus of small cats including the domestic cat Felis Felis is a genus of small felids that includes the domestic cat and several wild relatives. This article covers their traits, species, distribution, evolution, behavior and conserv…

Fennec fox (Vulpes zerda) Fennec fox A small, nocturnal desert fox native to North Africa and parts of the Arabian Peninsula, noted for its oversized ears, burrowing habits, and adaptations to hot, arid environments.

Ferret: domestic mustelid (Mustela putorius furo) — traits, history and care Ferret Comprehensive primer on the domestic ferret: biology, appearance, behaviour, origins, care essentials, common health issues, and how they differ from wild polecats.

Filter feeder: organisms that capture suspended food from water Filter feeder Filter feeders are animals that obtain food by straining suspended particles from water. Found across many groups, they shape ecosystems, aid water clarity, and evolved multiple ti…

Fin whale (Balaenoptera physalus) — the fast rorqual Fin whale A large baleen whale species, the fin whale is the second-largest animal, a fast rorqual with distinctive coloration, global distribution, and important ecological roles. Threats i…

Finch: overview, characteristics, taxonomy, and relationship with humans Finch Finches are small passerine songbirds noted for stout, seed‑crushing bills, diverse plumage and songs, and a complex taxonomy; important in ecological roles, aviculture and studies…

Finless porpoise A small, dorsal-finless toothed whale of Asian coastal and river waters. Related to dolphins, it uses echolocation, faces habitat loss and bycatch, and includes critically endanger…

Fiordland penguin (Eudyptes pachyrhynchus) — tawaki Fiordland penguin A crested penguin native to southwestern New Zealand, the Fiordland penguin (tawaki) nests in coastal forest, feeds on fish, squid and krill, and faces threats from introduced pred…

Fire ant (stinging ants of genus Solenopsis) Fire ant Fire ants are aggressive, stinging ants native to South America that have become invasive pests in many regions. They build large colonies, deliver painful alkaloid stings, and aff…

Fire salamander (Salamandra salamandra) Fire salamander A widespread European salamander noted for black-and-yellow coloration, toxic skin secretions, varied reproductive modes, long lifespan, and local conservation concerns from habita…

Firefly (Lampyridae): the bioluminescent 'lightning bugs' Firefly Fireflies (family Lampyridae) are bioluminescent beetles known for nocturnal flashes used in mating and defense. This article explains their biology, life cycle, behavior, and cons…

Fish: diversity, anatomy, evolution, and human importance Fish Fish are aquatic vertebrates with gills and fins; this article covers their anatomy, major groups, habitats, evolution, uses, and conservation concerns.

Fish lice (Argulidae): parasitic crustaceans of freshwater fish Fish lice Fish lice (family Argulidae) are external parasitic crustaceans that infect fish, causing tissue damage and disease risk. This article explains their biology, life cycle, impacts,…

Fishing cat (Prionailurus viverrinus): wetland specialist of South and Southeast Asia Fishing cat An overview of the fishing cat (Prionailurus viverrinus): appearance, behavior, habitat, diet, threats and conservation, with distinctions from similar small wild cats.

Flame-throated bulbul (Rubigula gularis) Flame-throated bulbul A bright yellow bulbul endemic to India’s Western Ghats, noted for its black head and vivid red throat patch. Found in forest edges and thick shrub, it feeds on fruit and insects a…

Flamingo: Ecology, Behavior, and Species of the Family Phoenicopteridae Flamingo Comprehensive guide to flamingos (Phoenicopteridae): ecology and wetland habitats, filter-feeding bills and diet, social and breeding behavior, plumage pigmentation, species distri…

Flanimals (fictional creatures created by Ricky Gervais) Flanimals Flanimals is a compendium of invented creatures by comedian Ricky Gervais with illustrations by Rob Steen. Humorous species profiles mix absurd biology, quirky names and whimsical…

Flatback turtle (Natator depressus): biology, range and conservation Flatback turtle An authoritative overview of the flatback sea turtle, Natator depressus — an Australian endemic. Covers appearance, habitat, behaviour, threats, conservation status and how it diff…

Flatfish: biology, adaptations, and human uses Flatfish Flatfish (order Pleuronectiformes) are laterally compressed benthic fishes with both eyes on one side; they include flounder, sole, turbot and halibut and are notable for camouflag…

Flatworm (Platyhelminthes): biology, classification, and impact Flatworm Flatworms (Platyhelminthes) are dorsoventrally flattened invertebrates. This article summarizes their anatomy, diversity, life cycles, ecological roles, and significance as parasit…

Flea (Siphonaptera): biology, lifecycle, health effects and control Flea Small, wingless blood-feeding insects (order Siphonaptera) that parasitize mammals and birds. Overview of appearance, lifecycle, role in disease transmission, historical impact and…

Flemish Giant rabbit Large, docile domestic rabbit breed developed in Flanders. Bred historically for meat and fur, now kept as pets, show animals and therapy companions; noted for size, calm temperame…

Flesh-footed Shearwater (Puffinus carneipes) Flesh-footed shearwater A medium-sized southern shearwater with distinctive pale pink feet; breeds on islands around Australia and New Zealand and faces threats from fisheries, plastics and introduced pre…

Flightless birds: characteristics, evolution, and human interactions Flightless birds Flightless birds are species that lost powered flight and adapted to running or swimming. This article covers their anatomy, examples, evolutionary causes, human uses, and conserva…

Flounder: flatfish of coastal seabeds — biology, life cycle, and human uses Flounder Flounder are bottom-dwelling flatfish in the suborder Pleuronectoidei known for eye migration, camouflage, and importance to fisheries and coastal ecosystems.

Fly (Diptera): anatomy, behavior, diversity and human significance Fly An overview of flies (order Diptera): defining features, flight anatomy, life cycle, ecological roles, diversity, and interactions with people, including disease transmission and s…

Flying fish: gliding marine fishes of the family Exocoetidae Flying fish Small, oceanic fishes able to glide above the sea surface using enlarged fins. Overview of their anatomy, behaviour, evolution, and interactions with humans and predators.

Flying frog (gliding treefrog) Flying frog Arboreal frogs that glide between trees using extensive webbing and skin flaps. Mostly tropical, best known in the Old World genus Rhacophorus; glide to escape predators and move i…

Flying possum (gliding marsupials) Flying possum Flying possums, or gliders, are small to medium marsupials from Australia and New Guinea that use a gliding membrane to travel between trees. This article explains their biology, d…

Flying squirrel: nocturnal gliding rodents of the Sciuridae family Flying squirrel Overview of flying squirrels: their anatomy, behavior, distribution, diet, predators, reproduction, differences from other gliding animals, and links to further resources.

Foot-and-mouth disease (FMD) Foot-and-mouth disease A highly contagious viral disease of cloven-hoofed animals caused by foot-and-mouth disease virus, with major impact on livestock health, trade and agricultural economies worldwide…

Forest dormice (genus Dryomys) Forest dormice Small nocturnal rodents of the genus Dryomys found across Eurasian forests and thickets; arboreal, hibernating, and ecologically important as seed eaters and prey species.

Forest dormouse (Dryomys nitedula) Forest dormouse Small nocturnal rodent of the Gliridae family found across much of Eurasia; arboreal, hibernating in cold months, and important for forest ecology and scientific study.

Formicariidae — ground antbirds of Central and South America Formicariidae Formicariidae are small, ground-dwelling passerine birds of tropical Central and South America. This entry summarizes their appearance, behavior, habitat, taxonomy, reproduction an…