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Rivers & wetlands

Rivers, lakes, marshes and swamps store fresh water and pack in disproportionate biodiversity. Wetlands are also among the most rapidly disappearing habitats on Earth.

34 animals in this habitat

Amphibians LC American Bullfrog Lithobates catesbeianus The American bullfrog is the largest frog in North America, a sit-and-wait predator that eats anything it can swallow — and one of the world's most damaging invasive amphibians. Read the guide →
Fish LC Archerfish Toxotes jaculatrix The archerfish hunts by spitting a precise jet of water to knock insects off overhanging leaves — correcting for the way light bends at the surface, and learning the skill by watching other fish. Read the guide →
Fish LC Atlantic Mudskipper Periophthalmus barbarus The Atlantic mudskipper is a fish that spends most of its life out of water, walking on its fins across mudflats, breathing through its skin and mouth, and defending a burrow it digs with its jaws. Read the guide →
Fish LC Atlantic Salmon Salmo salar The Atlantic salmon hatches in a river, migrates thousands of kilometres out to sea, then navigates back to its birth stream to spawn — guided by the Earth's magnetic field and by smell. Read the guide →
Fish VU Bull Shark Carcharhinus leucas The bull shark is the shark that swims up rivers — hundreds or thousands of kilometres into fresh water. Learn how it survives there, why it's rated among the most dangerous sharks, and its status. Read the guide →
Amphibians LC Cane Toad Rhinella marina The cane toad was released in Australia in 1935 to eat beetles and became one of the worst invasive species in the world. Learn why it is toxic, how far it has spread, and what is being done. Read the guide →
Mammals LC Capybara Hydrochoerus hydrochaeris The capybara is the world's largest rodent — a 50-kilogram, semi-aquatic grazer famous for its calm tolerance of almost every other animal. Learn how it lives in the wetlands of South America. Read the guide →
Amphibians LC Eastern Newt Notophthalmus viridescens The eastern newt of North America has a three-stage life — aquatic larva, land-dwelling orange "red eft," then aquatic adult — and its skin carries a nerve toxin that keeps predators away. Read the guide →
Fish LC Electric Eel Electrophorus electricus The electric eel is not an eel but a knifefish that generates up to 860 volts — the strongest electric discharge of any animal. Learn how it stuns prey, breathes air, and leaps to shock threats. Read the guide →
Birds LC Flamingo Phoenicopterus roseus The flamingo is a filter-feeding wading bird that eats with its head upside down, gets its pink colour entirely from its food, and breeds in colonies tens of thousands strong on caustic salt lakes. Read the guide →
Reptiles CR Gharial Gavialis gangeticus The gharial is a Critically Endangered Indian river crocodilian with a long thin snout built only for catching fish. Fewer than 1,000 breeding adults remain in a handful of rivers. Read the guide →
Reptiles LC Green Iguana Iguana iguana The green iguana is a large tree-dwelling lizard of the American tropics — a leaf-eating reptile with a third eye on its head that has become a damaging invasive species in Florida. Read the guide →
Amphibians NT Hellbender Cryptobranchus alleganiensis The hellbender is North America's largest salamander, a flat, wrinkled river-dweller up to 70 cm long that breathes through its skin and needs some of the cleanest water on the continent. Read the guide →
Reptiles LC Indian Cobra Naja naja The Indian cobra is one of the "big four" snakes behind most of India's snakebite deaths. It spreads a spectacle-marked hood, and it is the snake of charmers' baskets and Hindu myth. Read the guide →
Mammals LC Moose Alces alces The moose is the largest deer on Earth, tall enough to wade chest-deep and dive for water plants. Learn about its two-metre antlers and why warming winters are killing it with ticks. Read the guide →
Mammals LC North American Beaver Castor canadensis The North American beaver is the continent's largest rodent and its most powerful ecosystem engineer, felling trees and damming streams to build the ponds it lives in. Learn how it works. Read the guide →
Amphibians VU Olm Proteus anguinus The olm is a blind, cave-dwelling European salamander with pale pink skin, external gills kept for life, and the ability to survive a decade without food. It may live past 100. Read the guide →
Birds LC Pileated Woodpecker Dryocopus pileatus The pileated woodpecker is a crow-sized red-crested bird that hammers rectangular holes deep into dead trees to reach carpenter ants, and its abandoned cavities house dozens of other forest species. Read the guide →
Mammals NT Platypus Ornithorhynchus anatinus The platypus is a venomous, egg-laying mammal that hunts with its eyes shut, sensing prey by electric field. Learn how this Australian oddity works and why it is now Near Threatened. Read the guide →
Fish LC Red-Bellied Piranha Pygocentrus nattereri The red-bellied piranha is a South American river fish with interlocking razor teeth and a fearsome reputation that outruns the facts. It shoals for safety, scavenges widely, and rarely bites people. Read the guide →
Birds VU Shoebill Balaeniceps rex The shoebill is a towering grey swamp bird with a huge clog-shaped bill that it uses to catch lungfish and baby crocodiles. It stands motionless for hours, then strikes in a full-body lunge. Read the guide →
Amphibians LC Surinam Toad Pipa pipa The Surinam toad is a flat, leaf-shaped aquatic frog whose babies erupt from pits in the mother's back. It has no tongue or teeth and feels for prey with star-tipped fingers in murky water. Read the guide →
Mammals LC Wild Boar Sus scrofa The wild boar is the ancestor of the domestic pig, one of the most widespread mammals on Earth, and — as feral hogs — one of the most destructive invasive animals. Learn how it lives and spreads. Read the guide →
Amphibians LC Wood Frog Lithobates sylvaticus The wood frog survives being frozen solid every winter — heart stopped, most of its body water ice — then thaws back to life in spring. It ranges farther north than any other American frog. Read the guide →
Reptiles LC American Alligator Alligator mississippiensis The American alligator is a freshwater ambush predator and an ecosystem engineer whose "gator holes" keep wetlands alive. Learn how it survives freezing water and how it came back from the brink. Read the guide →
Amphibians CR Axolotl Ambystoma mexicanum The axolotl is a salamander that never grows up — it keeps its gills and stays underwater for life, and it can regrow lost limbs. Learn why it's beloved in labs and nearly extinct in the wild. Read the guide →
Birds LC Bald Eagle Haliaeetus leucocephalus The bald eagle is a fish-hunting sea eagle and a rare conservation success — back from near-extinction in the US. Learn about its huge nests, its eyesight, and why it isn't actually bald. Read the guide →
Reptiles LC Green Anaconda Eunectes murinus The green anaconda is the heaviest snake in the world, a non-venomous constrictor that ambushes prey from the water. Learn how it kills, why females dwarf males, and how it gives birth. Read the guide →
Mammals VU Hippopotamus Hippopotamus amphibius The hippopotamus spends its days in water and its nights grazing on land, sweats a red antibiotic sunscreen, and is one of Africa's most dangerous animals. Learn how this river giant lives. Read the guide →
Mammals NT Jaguar Panthera onca The jaguar is the biggest cat in the Americas and has the strongest bite of any big cat for its size — it kills by piercing the skull. Learn how it hunts in water and why it's Near Threatened. Read the guide →
Reptiles VU King Cobra Ophiophagus hannah The king cobra is the world's longest venomous snake and the only one that builds a nest for its eggs. Learn how it hunts other snakes, why it rears up, and what its venom does. Read the guide →
Reptiles LC Reticulated Python Malayopython reticulatus The reticulated python is the longest snake in the world, a non-venomous constrictor that swims between islands and lives alongside people across Southeast Asia. Learn how it hunts and breeds. Read the guide →
Reptiles LC Saltwater Crocodile Crocodylus porosus The saltwater crocodile is the largest living reptile and has the strongest bite ever measured. Learn how it ambushes prey, crosses open ocean, and how it recovered from near-extinction. Read the guide →
Mammals EN Tiger Panthera tigris The tiger is the largest cat on Earth and a solitary ambush hunter. Learn how it stalks prey, why every tiger's stripes are unique, and why fewer than 5,600 remain wild. Read the guide →