Atelopus longirostris — the long-snouted harlequin frog of Ecuador Atelopus longirostris A concise, neutral overview of Atelopus longirostris: appearance, range in northern Ecuador, history of decline and rediscovery, threats, and conservation considerations.
Atheris — African bush vipers (arboreal venomous snakes) Atheris Atheris is a genus of small to medium arboreal vipers native to African rainforests. Known as bush vipers, they have rough keeled scales, prehensile tails, live birth, potent venom…
Athous — a genus of click beetles Athous Athous is a large genus of click beetles (Elateridae) whose larvae, called wireworms, feed on roots and seeds and can damage crops. The genus was established by Eschscholtz in 1829…
Atlantic cod (Gadus morhua): biology, fisheries and conservation Atlantic cod Comprehensive overview of Atlantic cod—its biology, habitat, role in fisheries and cultural importance—plus history of exploitation and contemporary conservation measures.
Atlantic herring (Clupea harengus) Atlantic herring A widely distributed, schooling pelagic fish of the North Atlantic valued for food and fish oil; important ecologically and economically and subject to fisheries management and con…
Atlantic mackerel (Scomber scombrus) Atlantic mackerel A common North Atlantic pelagic fish, the Atlantic mackerel forms large schools, is important to commercial fisheries, and is valued as an oily food fish. Overview of biology, rang…
Atlantic sailfish (Istiophorus albicans) Atlantic sailfish A fast, pelagic predator of the Atlantic and Caribbean, notable for its sail-like dorsal fin, elongated bill, and role in sport fisheries and open-ocean ecosystems.
Atlantic salmon (Salmo salar): biology, distribution, life cycle and conservation Atlantic salmon Anadromous North Atlantic fish, Salmo salar is important for wild fisheries, angling and aquaculture. This summary covers its life stages, habitat, human impacts, management and co…
Atlantic sturgeon — large anadromous fish of the Atlantic coast Atlantic sturgeon Overview of the Atlantic sturgeon: appearance, life cycle, historical range, threats from fishing and pollution, and contemporary conservation efforts.
Atrax: the Sydney funnel-web spiders — overview, venom, and distinctions Atrax Atrax is a small genus of robust Australian funnel-web spiders noted for potent venom, burrow-based funnel webs, and medical significance. This article covers biology, behavior, di…
Atropoides — the jumping pitvipers: overview, traits and distribution Atropoides Atropoides is a small genus of venomous pit vipers native to Mexico and Central America. Known as jumping pitvipers, these stout snakes are notable for their strike behavior, habit…
Attacus atlas (atlas moth) Attacus atlas A very large tropical moth from Southeast Asia, famed for its huge wings, snake-head wing tips, short adult life without feeding, and its life cycle from leaf-eating caterpillar to…
Aucasaurus — a Cretaceous abelisaurid from Argentina Aucasaurus Aucasaurus is a medium-sized abelisaurid theropod from Late Cretaceous Argentina. Known from a relatively complete skeleton, it had very short forelimbs, a stout skull, and adds to…
Aularches (Aularches miliaris): foam‑squirting, brightly colored grasshopper Aularches Aularches miliaris is a conspicuously colored grasshopper from South and Southeast Asia noted for its rasping alarm and a bitter, foamy defensive secretion that deters predators.
Aurochs (Bos primigenius): wild ancestor of modern cattle Aurochs Aurochs were large wild cattle (Bos primigenius) once widespread across Eurasia and North Africa; they are the wild progenitor of domestic cattle and became extinct in the early 17…
Aurornis xui: basal bird-like theropod from Late Jurassic–Early Cretaceous China Aurornis Aurornis xui, a basal bird-like theropod from Late Jurassic–Early Cretaceous China, known from a near-complete fossil; its age and primitive features illuminate early avian evoluti…
Australian Kelpie A medium-sized Australian herding dog bred for endurance, intelligence and independent work. Used worldwide for mustering sheep, cattle and goats; noted for high energy, trainabili…
Australian megafauna: giant prehistoric animals of Pleistocene Australia Australian megafauna Large-bodied Australian animals of the Pleistocene — unique marsupials, giant birds and monotremes — known from fossils and Aboriginal traditions; extinct mainly by the late Pleist…
Australian Mist (cat breed) Australian Mist Australian Mist is a medium short-haired cat breed developed in Australia for a spotted or marbled coat and a calm, people-oriented temperament.
Australidelphia — superorder of Australasian marsupials Australidelphia Australidelphia is a major marsupial superorder that includes most Australasian species plus the South American monito del monte, encompassing diverse orders such as kangaroos, pos…
Australosphenida Australosphenida: a proposed clade of mainly Mesozoic southern mammals that includes the living monotremes (platypus and echidnas) and several extinct Gondwanan genera; important f…
Australovenator — Australian Cretaceous theropod Australovenator Australovenator was a medium-sized predatory dinosaur from Early Cretaceous Australia, discovered near Winton, Queensland. Its relatively complete skeleton reshaped understanding o…
Automeris io (Io moth): appearance, life cycle, range and defenses Automeris io Automeris io, the Io moth, is a North American saturniid notable for its striking hindwing eyespots, stinging caterpillars, nocturnal adults and wide range from southern Canada to…
Avemetatarsalia — bird-line archosaurs (Panaves) Avemetatarsalia Avemetatarsalia, or Panaves, is the clade of archosaurs closer to birds than to crocodiles; it includes dinosaurs (and birds), pterosaurs, and several early relatives that shaped t…
Aviatyrannis — early tyrannosauroid from Portugal Aviatyrannis Aviatyrannis is an early, small-bodied tyrannosauroid dinosaur discovered in Portugal in 2000 and named in 2003. Known from fragmentary remains, it informs the early evolution and…
Avimimus — a small bird‑like maniraptoran dinosaur Avimimus Avimimus, a small Late Cretaceous maniraptoran from Mongolia, combined lightweight, cursorial anatomy with birdlike features. Known from two species, it illuminates the diversity o…
Axolotl (Ambystoma mexicanum): aquatic salamander, neoteny, and regeneration Axolotl Axolotl, Ambystoma mexicanum, is a neotenic Mexican salamander noted for external gills, remarkable regenerative ability, cultural importance, and conservation concern in its nativ…
Aye-aye (Daubentonia madagascariensis) Aye-aye A nocturnal lemur endemic to Madagascar, the aye-aye is notable for its rodent-like teeth and an elongated middle finger used to extract insect larvae from wood, filling a woodpeck…
Azemiopinae — Fea's vipers, a distinctive viper subfamily Azemiopinae A small, distinctive group of vipers centered on the genus Azemiops (Fea's vipers), native to mountainous forests of Southeast Asia and southern China; noted for unique anatomy, ma…
Azure kingfisher (Alcedo azurea) Azure kingfisher A small, brightly colored river kingfisher of Australia, Tasmania, New Guinea and nearby islands. Noted for its blue back, red feet, perch‑and‑dive hunting and burrow nests in cree…
Babirusa (Babyrousa): the deer-pigs of Wallacea Babirusa Babirusas are distinctive wild pigs of the genus Babyrousa from Wallacea (Sulawesi and nearby islands), notable for upward-curving tusks, unusual skull morphology and conservation…
Baboon (genus Papio): biology, behavior and human interactions Baboon Large, terrestrial Old World monkeys of the genus Papio. Baboons form complex social troops, occupy diverse African and Arabian habitats, and play notable ecological and cultural r…
Bactrosaurus: an early hadrosauroid from the Late Cretaceous Bactrosaurus Bactrosaurus was a plant-eating hadrosauroid from the Late Cretaceous Gobi Desert of China, about 6 m long. Notable for its primitive duckbill features and an unusually high incide…
Badger — natural history, behavior, and relationships with people Badger Badgers are short-legged, burrowing mustelids found across much of the world. This article summarizes their biology, common species, behavior, burrows (setts), cultural roles, and…
Badjcinus: an early Oligocene thylacinid Badjcinus Badjcinus was a small, primitive member of the extinct marsupial family Thylacinidae from early Oligocene Australia, known from Riversleigh fossils and interpreted as a generalized…
Bagaceratops — small horned-face ceratopsian Bagaceratops Bagaceratops, a small beaked ceratopsian from Late Cretaceous Mongolia, had a short frill and no large horns. Fossils reveal its anatomy, ecology, and importance for understanding…
Bagualosaurus — a small Late Triassic sauropodomorph from southern Brazil Bagualosaurus Bagualosaurus is an early sauropodomorph dinosaur from the Late Triassic of southern Brazil, described in 2018 from a partial skeleton and notable for its role in understanding sau…
Baird's tapir (Tapirus bairdii) Baird's tapir Baird's tapir is a large, forest-dwelling herbivore native to Central America and parts of northern South America. It is a key seed disperser and is threatened by habitat loss and…
Bait (attractants used in fishing, hunting and trapping) Bait Bait: substances or devices used to attract animals for capture, study, or deterrence. Covers natural and artificial types, presentation methods, history, examples, and legal/ethic…
Balaenoptera: rorqual whales of the Balaenopteridae genus Balaenoptera Balaenoptera is the largest genus of rorqual whales, including the blue, fin, sei, minke, Bryde’s and Omura’s whales. Overview of traits, species, feeding, history, and conservatio…
Omura's whale (Balaenoptera omurai) Balaenoptera omurai Omura's whale (Balaenoptera omurai) is a small rorqual from tropical and subtropical Indo-Pacific waters. It is little known, related to the Bryde's whale complex, and the subject…
Balaur — an unusual Late Cretaceous theropod from Hațeg Island Balaur Balaur was a stocky Late Cretaceous theropod from Hațeg Island, notable for two sickle claws per foot, reduced forelimb digits and debated placement among dromaeosaurids or avialan…
Bald eagle (Haliaeetus leucocephalus): North America's sea eagle Bald eagle A large bird of prey native to North America, the bald eagle is a sea eagle known for its white head, cultural importance in the United States, and recovery from serious decline.
Balochistan forest dormouse (Dryomys niethammeri) Balochistan forest dormouse A small, little-known dormouse species endemic to Pakistan’s Balochistan region. Overview of its identity, likely habits, habitat, conservation concerns, and how it differs from ot…
Baltimore oriole (Icterus galbula): appearance, behavior, and cultural role Baltimore oriole A migratory songbird of eastern North America noted for bright orange-and-black males, woven hanging nests, and ties to Maryland; common in gardens and woodlands, feeding on insect…
Balto: sled dog hero of the 1925 serum run Balto Balto, a Siberian Husky sled dog, led the final stage of the 1925 Nome serum relay and became a symbol of the dogs and mushers who saved lives during a diphtheria outbreak.
Bambi (fictional deer character) Bambi (character) Bambi is a fictional deer who originated in Felix Salten's novel and became widely known through Disney films. The character illustrates coming-of-age, nature, and human impact on…
Banded stilt (Cladorhynchus leucocephalus) Banded stilt An Australian wading bird known for its chest band, nomadic breeding on ephemeral salt lakes and dependence on brine shrimp; locally vulnerable though not globally rare.
