Animals

Atheris

Atheris — African bush vipers (arboreal venomous snakes)

Athous

Athous — a genus of click beetles

Atlantic cod

Atlantic cod (Gadus morhua): biology, fisheries and conservation

Atlantic herring

Atlantic mackerel

Atlantic mackerel (Scomber scombrus)

Atlantic sailfish

Atlantic sailfish (Istiophorus albicans)

Atlantic salmon

Atlantic salmon (Salmo salar): biology, distribution, life cycle and conservation

Atlantic sturgeon

Atlantic sturgeon — large anadromous fish of the Atlantic coast

Atrax

Atropoides

Atropoides — the jumping pitvipers: overview, traits and distribution

Attacus atlas

Aucasaurus

Aularches

Aurochs

Aurornis

Aurornis xui: basal bird-like theropod from Late Jurassic–Early Cretaceous China

Australian Kelpie

Australian megafauna

Australian Mist

Australian Mist (cat breed)

Australidelphia

Australosphenida

Australovenator

Automeris io

Automeris io (Io moth): appearance, life cycle, range and defenses

Avemetatarsalia

Avemetatarsalia — bird-line archosaurs (Panaves)

Aviatyrannis

Avimimus

Avimimus — a small bird‑like maniraptoran dinosaur

Axolotl

Axolotl (Ambystoma mexicanum): aquatic salamander, neoteny, and regeneration

Aye-aye

Azemiopinae

Azemiopinae — Fea's vipers, a distinctive viper subfamily

Azure kingfisher

Azure kingfisher (Alcedo azurea)

Babirusa

Baboon

Baboon (genus Papio): biology, behavior and human interactions

Bactrosaurus

Badger

Badger — natural history, behavior, and relationships with people

Badjcinus

Bagaceratops

Bagaceratops — small horned-face ceratopsian

Bagualosaurus

Baird's tapir

Baird's tapir (Tapirus bairdii)

Bait

Bait (attractants used in fishing, hunting and trapping)

Balaenoptera

Balaenoptera: rorqual whales of the Balaenopteridae genus

Balaenoptera omurai

Omura's whale (Balaenoptera omurai)

Balaur

Bald eagle

Bald eagle (Haliaeetus leucocephalus): North America's sea eagle

Balochistan forest dormouse

Balochistan forest dormouse (Dryomys niethammeri)

Baltimore oriole

Baltimore oriole (Icterus galbula): appearance, behavior, and cultural role

Balto

Bambi (character)

Bambi (fictional deer character)

Banded stilt

Banded stilt (Cladorhynchus leucocephalus)

Bandicoot

Bandicoot: small omnivorous marsupials of Australasia