World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/sawfish): Sawfish — wildlife guide.

## Are sawfish sharks?
No, they are rays. Despite the elongated shark-like body, sawfish belong to the family Pristidae within the rays, with gill slits on the underside of the body as rays have rather than on the sides as sharks do.

## What is a sawfish's saw for?
Both sensing and striking. The rostrum is covered in electroreceptors that detect prey buried in sediment or moving in murky water, and the sawfish then sweeps it sideways to stun or impale small fish.

## Why are sawfish so endangered?
The rostrum entangles in almost any net, so sawfish are caught even in fisheries that do not target them, and entangled animals often have the rostrum cut off to free the gear, which is fatal. Mangrove nursery loss and river modification compound it. All five species are threatened.

## Do sawfish live in rivers?
Yes, several species do. The largetooth sawfish has been recorded hundreds of kilometres up rivers in fresh water, which exposes it to damming, water extraction and inland fisheries as well as coastal pressures.

## What do sawfish eat?
Sawfish eat 5 — Sawfish species, all threatened. Sawfish are rays with a long tooth-lined rostrum used to sense and strike prey; all five species are threatened and most are Critically Endangered, largely because the rostrum entangles in fishing nets.

## Where do sawfish live?
Sawfish live in Coasts, estuaries and far up rivers. Sawfish are rays with a long tooth-lined rostrum used to sense and strike prey; all five species are threatened and most are Critically Endangered, largely because the rostrum entangles in fishing nets.

## Are sawfish dangerous?
Sawfish are not generally dangerous to people. Sawfish are rays with a long tooth-lined rostrum used to sense and strike prey; all five species are threatened and most are Critically Endangered, largely because the rostrum entangles in fishing nets. Give wild individuals space and do not corner or handle them.

## How long do sawfish live?
A precise wild lifespan for sawfish is not firmly established in the sources cited on this guide. Sawfish are rays with a long tooth-lined rostrum used to sense and strike prey; all five species are threatened and most are Critically Endangered, largely because the rostrum entangles in fishing nets. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

## How big is a sawfish?
A Sawfish is about ~7 m (largetooth sawfish). Sawfish are rays with a long tooth-lined rostrum used to sense and strike prey; all five species are threatened and most are Critically Endangered, largely because the rostrum entangles in fishing nets. Conservation status: CITES Appendix I.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/mantis-shrimp): Mantis Shrimp — wildlife guide.

## One-line answer
Mantis shrimp are stomatopod crustaceans whose raptorial strike is fast enough to vaporise water and produce a cavitation shockwave, and whose eyes carry up to sixteen photoreceptor types plus polarised-light vision.

## Introduction
Mantis shrimp are stomatopod crustaceans, not shrimp, with two of the most extraordinary systems in the animal world. Their raptorial appendages strike so fast that the water beside them briefly vaporises, producing a cavitation bubble whose collapse delivers a second shockwave — so the prey is hit twice, and a mantis shrimp can break aquarium glass.

Their eyes are equally unusual. Where humans have three colour receptor types, mantis shrimp have up to sixteen, along with the ability to detect polarised light. Counterintuitively, this does not make them better at discriminating colours than we are — the current evidence suggests they trade discrimination for speed, recognising colour directly rather than comparing signals.

## Takeaway
Mantis shrimp are stomatopods, not true shrimp.

## Takeaway
The strike is fast enough to vaporise water, producing a second shockwave on bubble collapse.

## Takeaway
Smashers club hard-shelled prey; spearers impale soft prey.

## Takeaway
They have up to sixteen photoreceptor types and see polarised light.

## Takeaway
More receptors does not mean finer colour discrimination — evidence points to faster recognition instead.

## The strike
Smasher mantis shrimp store energy in a saddle-shaped spring in the appendage and release it in a latch-mediated snap. The club accelerates at a rate comparable to a small-calibre bullet, reaching around 23 metres per second in water.

The speed drops local pressure enough to vaporise water, forming a cavitation bubble. When that bubble collapses it releases a second burst of energy, along with light and heat. Prey is therefore struck twice — once by the club, once by the implosion — which is how a mantis shrimp opens crab shells and, in aquariums, cracks glass.

## Two toolkits
Stomatopods split into two broad strategies. Smashers carry blunt clubs for battering hard-shelled prey: crabs, snails and molluscs. Spearers carry barbed, folding appendages for impaling soft prey such as fish and shrimp, striking with the same latch mechanism but a different tip.

The club is a material of considerable engineering interest. Its layered, helical structure resists the enormous repeated impacts without shattering, and it has been studied directly as a model for impact-resistant composites.

## The eyes, accurately described
Mantis shrimp eyes are mounted on stalks, move independently, and each eye has trinocular depth perception on its own. They carry up to sixteen photoreceptor types spanning ultraviolet into the visible range, and can detect both linear and circular polarised light — the only animals known to do the latter.

The popular claim that they therefore see unimaginably rich colour appears to be wrong. Behavioural tests showed they discriminate similar wavelengths less finely than humans do. The favoured explanation is that they recognise colour directly at each receptor rather than by comparing across receptors, trading precision for speed — useful for an ambush predator that must identify a target instantly.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/mantis-shrimp): Mantis Shrimp — wildlife guide.

## Behaviour and keeping
Many species are territorial and hold burrows, and some form long-term monogamous pairs. They are intelligent by invertebrate standards, learning to recognise individual neighbours by sight and smell.

In the aquarium trade they are prized and problematic in equal measure: a smasher can break tank glass, and they will kill tankmates. Responsible keeping means a species-appropriate solo tank with acrylic or thick glass, which is a specialist commitment rather than a casual one.

## WARN work
WARN publishes free, sourced species education including where popular claims and the underlying research diverge. The mantis shrimp's colour vision is one of the most confidently repeated wrong facts on the internet, and correcting it is more interesting than the myth.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/mantis-shrimp): Mantis Shrimp — wildlife guide.

## How powerful is a mantis shrimp punch?
The club of a smasher accelerates to around 23 metres per second in water, fast enough to drop local pressure and vaporise water into a cavitation bubble. When that bubble collapses it delivers a second shockwave, so prey is hit twice. A mantis shrimp can break aquarium glass.

## Can mantis shrimp see more colours than humans?
Not in the way usually claimed. They have up to sixteen photoreceptor types against our three, but behavioural tests showed they discriminate similar wavelengths less finely than we do. The evidence suggests they recognise colour directly at each receptor for speed rather than comparing across receptors for precision.

## Are mantis shrimp actually shrimp?
No. They are stomatopods, a separate order of crustaceans that diverged from true shrimp and prawns hundreds of millions of years ago.

## What is the difference between smashers and spearers?
Smashers have blunt clubs for battering hard-shelled prey such as crabs and snails. Spearers have barbed, folding appendages for impaling soft prey such as fish. Both use the same spring-and-latch mechanism with a different tip.

## What do mantis shrimp / stomatopods eat?
Mantis Shrimp / Stomatopods eat Cavitation — The strike creates a bubble whose collapse hits prey a second time. Mantis shrimp are stomatopod crustaceans whose raptorial strike is fast enough to vaporise water and produce a cavitation shockwave, and whose eyes carry up to sixteen photoreceptor types plus polarised-light vision.

## Where do mantis shrimp / stomatopods live?
Mantis Shrimp / Stomatopods live in Tropical and subtropical shallow seas worldwide, Reefs, rubble and burrows in soft sediment. Mantis shrimp are stomatopod crustaceans whose raptorial strike is fast enough to vaporise water and produce a cavitation shockwave, and whose eyes carry up to sixteen photoreceptor types plus polarised-light vision.

## Are mantis shrimp / stomatopods dangerous?
Mantis Shrimp / Stomatopods are not generally dangerous to people. Mantis shrimp are stomatopod crustaceans whose raptorial strike is fast enough to vaporise water and produce a cavitation shockwave, and whose eyes carry up to sixteen photoreceptor types plus polarised-light vision. Give wild individuals space and do not corner or handle them.

## How long do mantis shrimp / stomatopods live?
A precise wild lifespan for mantis shrimp / stomatopods is not firmly established in the sources cited on this guide. Mantis shrimp are stomatopod crustaceans whose raptorial strike is fast enough to vaporise water and produce a cavitation shockwave, and whose eyes carry up to sixteen photoreceptor types plus polarised-light vision. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

## How big is a mantis shrimp / stomatopod?
Mantis shrimp are stomatopod crustaceans whose raptorial strike is fast enough to vaporise water and produce a cavitation shockwave, and whose eyes carry up to sixteen photoreceptor types plus polarised-light vision.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/ocean-sunfish): Ocean Sunfish — wildlife guide.

## One-line answer
The ocean sunfish (Mola mola) is the heaviest bony fish alive at over two tonnes, has no true tail fin, feeds largely on gelatinous plankton, and grows to around 60 million times its larval weight.

## Introduction
The ocean sunfish is the heaviest bony fish alive, reaching over two tonnes, and one of the strangest-looking animals in the sea. It appears to be all head — the body ends abruptly in a rudder-like structure called a clavus, formed where a normal tail fin would be, giving it a truncated, disc-shaped profile.

It begins life as a larva a few millimetres long covered in spines, and can grow to roughly 60 million times that weight, one of the most extreme size changes of any vertebrate.

## Takeaway
Ocean sunfish are the heaviest bony fish alive, exceeding two tonnes.

## Takeaway
They have no true tail fin — a rudder-like clavus takes its place.

## Takeaway
Larvae are a few millimetres long and covered in spines.

## Takeaway
They dive to several hundred metres and bask at the surface to rewarm.

## Takeaway
Bycatch in drift and gill nets is the principal threat.

## A body built by subtraction
Sunfish lose the tail fin during development. What remains is the clavus, a stiff rudder formed from modified fin rays, which the fish uses for steering while the tall dorsal and anal fins provide propulsion, sculled from side to side.

The skeleton is largely cartilage rather than heavy bone, and the body carries a thick layer of gelatinous tissue under the skin. That combination keeps a two-tonne animal buoyant without the swim bladder that most bony fish rely on.

## Basking, and why
Sunfish are often seen lying on their side at the surface, which produced the common name. This is thermoregulation: after diving into cold water at several hundred metres to feed, the fish returns to the surface to rewarm in sunlight.

The posture may serve a second purpose. Surface-basking sunfish are visited by seabirds that pick parasites off the skin, and the fish also visit cleaner-fish stations on reefs — a large animal with a heavy parasite load using two different cleaning services.

## Diet and the jellyfish problem
Sunfish were long described as feeding almost entirely on jellyfish. Better dietary studies show a broader diet including small fish, crustaceans, squid and salps, though gelatinous prey remains important.

That gelatinous preference creates a specific hazard: floating plastic bags closely resemble jellyfish, and sunfish ingest them. Plastic ingestion is a documented cause of death in the species.

## Why they are Vulnerable
Sunfish are rarely targeted commercially, but they are caught in enormous numbers as bycatch. In some drift-net and gill-net fisheries sunfish have made up a very large share of the total catch, and they are also taken in longlines.

They are listed as Vulnerable. Plastic ingestion, vessel strikes at the surface and the sheer scale of incidental capture are the pressures; targeted fishing is not.

## WARN work
WARN publishes free, sourced species education for animals that decline through incidental capture and marine litter rather than deliberate hunting. Sunfish illustrate both at once — a species almost nobody fishes for, dying in nets set for something else and eating plastic mistaken for jellyfish.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/ocean-sunfish): Ocean Sunfish — wildlife guide.

## What is the heaviest bony fish?
The ocean sunfish, at over two tonnes. Larger fish exist — whale sharks and basking sharks — but those are cartilaginous, so the sunfish holds the record among bony fish.

## Why do sunfish lie on their side at the surface?
To rewarm. Sunfish dive to several hundred metres into cold water to feed, then return to the surface and bask in sunlight to raise their body temperature. Seabirds also pick parasites from basking sunfish, so the behaviour serves twice.

## Do sunfish only eat jellyfish?
No — that was the traditional description, but better dietary studies show a broader diet including small fish, crustaceans, squid and salps. Gelatinous prey is still important, which is why floating plastic bags are dangerous to them.

## Why don't sunfish have a tail?
They lose the tail fin during development. A stiff rudder called the clavus, formed from modified fin rays, takes its place, while the tall dorsal and anal fins provide propulsion by sculling side to side.

## What do ocean sunfish / molas eat?
Ocean Sunfish / Molas eat 2,300 kg — Heaviest recorded — the heaviest bony fish. The ocean sunfish (Mola mola) is the heaviest bony fish alive at over two tonnes, has no true tail fin, feeds largely on gelatinous plankton, and grows to around 60 million times its larval weight.

## Where do ocean sunfish / molas live?
Ocean Sunfish / Molas live in Temperate and tropical oceans worldwide, Open ocean, often near the surface. The ocean sunfish (Mola mola) is the heaviest bony fish alive at over two tonnes, has no true tail fin, feeds largely on gelatinous plankton, and grows to around 60 million times its larval weight.

## Are ocean sunfish / molas dangerous?
Ocean Sunfish / Molas are not generally dangerous to people. The ocean sunfish (Mola mola) is the heaviest bony fish alive at over two tonnes, has no true tail fin, feeds largely on gelatinous plankton, and grows to around 60 million times its larval weight. Give wild individuals space and do not corner or handle them.

## How long do ocean sunfish / molas live?
A precise wild lifespan for ocean sunfish / molas is not firmly established in the sources cited on this guide. The ocean sunfish (Mola mola) is the heaviest bony fish alive at over two tonnes, has no true tail fin, feeds largely on gelatinous plankton, and grows to around 60 million times its larval weight. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

## How big is an ocean sunfish / mola?
An Ocean Sunfish / Mola is about ~2,300 kg. The ocean sunfish (Mola mola) is the heaviest bony fish alive at over two tonnes, has no true tail fin, feeds largely on gelatinous plankton, and grows to around 60 million times its larval weight. Conservation status: Bycatch in drift and gill nets.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/porpoise): Porpoise — wildlife guide.

## One-line answer
Porpoises are a separate family from dolphins, with blunt beakless heads, triangular dorsal fins and spade-shaped teeth; the family includes the vaquita, the most endangered marine mammal in the world.

## Introduction
Porpoises are frequently called dolphins, and they are not. They form their own family, Phocoenidae, distinguished by blunt heads with no beak, small triangular dorsal fins, and spade-shaped rather than conical teeth.

They are also, as a group, in trouble. Porpoises live in shallow coastal water — exactly where gillnets are set — and the family includes the vaquita, the most endangered marine mammal on Earth, reduced to a handful of individuals in the Gulf of California.

## Takeaway
Porpoises are their own family, not small dolphins.

## Takeaway
They have no beak, a triangular dorsal fin and spade-shaped teeth.

## Takeaway
They are less acrobatic and less vocal at audible frequencies than dolphins.

## Takeaway
Coastal habitat overlaps heavily with gillnet fisheries.

## Takeaway
The vaquita, a porpoise, is the most endangered marine mammal on Earth.

## How to tell a porpoise from a dolphin
Three reliable cues. Porpoises have blunt, rounded heads with no beak, while most dolphins have a distinct rostrum. Porpoise dorsal fins are small and triangular; dolphin fins are typically taller and curved back. And porpoise teeth are flattened and spade-shaped, where dolphin teeth are conical.

Behaviour differs too. Porpoises are generally less acrobatic, rarely bow-ride, and surface with a short quiet roll rather than the conspicuous leaping many dolphins show.

## Narrow-band high-frequency echolocation
Porpoises echolocate at very high frequencies in a narrow band, well above the hearing range of killer whales. The prevailing explanation is predator avoidance: by clicking above the frequencies orcas hear well, a porpoise can hunt without advertising itself.

That specialisation has a practical consequence for conservation. Because their clicks are so distinctive, acoustic monitoring can detect porpoise presence reliably, which is how populations in turbid coastal water are surveyed.

## Gillnets, and the vaquita
Porpoises live where people fish. Shallow coastal water and estuaries are prime gillnet grounds, and porpoises drown when entangled. Bycatch is the dominant cause of death across the family.

The vaquita is the extreme case. Confined to a small area of the northern Gulf of California, it has been driven to a handful of individuals by gillnets set illegally for totoaba, a fish whose swim bladder commands high prices in an illegal trade. The vaquita has never been targeted itself — it is dying entirely as bycatch of a different crime.

## What reduces bycatch
Acoustic deterrents fitted to nets reduce porpoise entanglement in some fisheries, and gear modification, seasonal closures and net-type restrictions all have evidence behind them. None work without enforcement.

The harbour porpoise, the most familiar species, remains relatively numerous but suffers heavy bycatch in some regions along with pollutant accumulation and underwater noise disturbance. The family as a whole illustrates that a species does not need to be hunted to be driven to the edge.

## WARN work
WARN publishes free, sourced species education for the animals lost as collateral. The vaquita is the starkest example in the ocean: a species that nobody has ever wanted to catch, being driven to extinction by nets set illegally for something else.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/porpoise): Porpoise — wildlife guide.

## What is the difference between a porpoise and a dolphin?
Porpoises are a separate family. They have blunt heads with no beak, small triangular dorsal fins and flattened spade-shaped teeth, where dolphins typically have a distinct beak, a taller curved fin and conical teeth. Porpoises are also less acrobatic and rarely bow-ride.

## How many porpoise species are there?
Seven, in the family Phocoenidae, including the harbour porpoise, Dall's porpoise, the finless porpoise and the vaquita.

## Why do porpoises echolocate at such high frequencies?
Most likely to avoid predators. Porpoise clicks are narrow-band and very high frequency, above the range killer whales hear well, so a porpoise can hunt without advertising its position to an orca.

## What is the most endangered marine mammal?
The vaquita, a porpoise found only in the northern Gulf of California, reduced to a handful of individuals. It is not hunted — it drowns in gillnets set illegally for totoaba, a fish whose swim bladder is trafficked at high value.

## Where do porpoises live?
Porpoises live in Coastal temperate and cold waters of the Northern Hemisphere and South America, Shallow seas, estuaries and some rivers. Porpoises are a separate family from dolphins, with blunt beakless heads, triangular dorsal fins and spade-shaped teeth; the family includes the vaquita, the most endangered marine mammal in the world.

## Are porpoises dangerous?
They form their own family, Phocoenidae, distinguished by blunt heads with no beak, small triangular dorsal fins, and spade-shaped rather than conical teeth. Give wild porpoises space; do not corner or handle them.

## How long do porpoises live?
A precise wild lifespan for porpoises is not firmly established in the sources cited on this guide. Porpoises are a separate family from dolphins, with blunt beakless heads, triangular dorsal fins and spade-shaped teeth; the family includes the vaquita, the most endangered marine mammal in the world. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/gray-whale): Gray Whale — wildlife guide.

## One-line answer
The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment.

## Introduction
The gray whale makes one of the longest migrations of any mammal, travelling up to roughly 20,000 km a year between Arctic feeding grounds and the lagoons of Baja California where it calves. It is also the only baleen whale that feeds primarily by rolling onto its side on the seafloor and sucking up sediment, straining amphipods from the mud.

The eastern North Pacific population recovered strongly after whaling ended, and is one of the clearest large-whale recovery stories. The western population did not, and remains Critically Endangered.

## Takeaway
Gray whales migrate up to roughly 20,000 km a year.

## Takeaway
They feed by rolling on the seabed and filtering amphipods from sediment.

## Takeaway
The eastern North Pacific population recovered strongly after whaling protection.

## Takeaway
The western Pacific population remains Critically Endangered.

## Takeaway
Whalers called them devil fish for the ferocity with which mothers defended calves.

## Feeding on the bottom
Gray whales are unique among baleen whales in feeding mainly from the seafloor. A whale rolls onto its side, usually the right, and suctions up sediment, then strains small crustaceans — principally amphipods — through short coarse baleen.

The habit leaves visible feeding pits on the seabed and stirs nutrients into the water column, so gray whales physically rework the Arctic shelf where they feed. Most individuals show more wear on the right side of the baleen, in the same way people are right-handed.

## The migration
Each autumn gray whales leave Arctic and sub-Arctic feeding grounds and travel south along the North American coast to shallow, warm, hypersaline lagoons in Baja California, where calves are born. In spring they return north.

Because the route hugs the coast, the migration is visible from land and supports substantial whale-watching. It also concentrates the entire population into a narrow coastal corridor, which makes them exposed to vessel traffic, entanglement and coastal development along the whole route.

## Recovery, and the population that did not recover
Commercial whaling reduced gray whales severely. After protection, the eastern North Pacific population rebounded to tens of thousands and was removed from the US endangered species list in 1994 — one of the strongest large-whale recovery cases on record.

The western North Pacific population, which feeds off Sakhalin, did not recover in the same way and remains Critically Endangered, with tracking showing some individuals crossing to the eastern side. The North Atlantic population was hunted to extinction centuries ago, though occasional strays now appear as Arctic ice retreats.

## Modern pressures
Gray whales face entanglement in fishing gear, vessel strikes along a coastal migration route, noise and disturbance from shipping and industrial activity, and changes in the Arctic benthic communities they depend on.

Unusual mortality events have been recorded in recent years, with large numbers of emaciated whales stranding, and reduced prey availability in warming Arctic feeding grounds is a leading hypothesis. A recovered population is not a secure one when its food supply is shifting.

## WARN work
WARN publishes free, sourced species education including conservation's genuine successes and their limits. The eastern gray whale shows that a heavily hunted large whale can recover once killing stops — and recent mortality events show that protection from hunting does not protect a species from what is happening to its food.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/gray-whale): Gray Whale — wildlife guide.

## How far do gray whales migrate?
Up to roughly 20,000 km on a round trip each year, between Arctic feeding grounds and calving lagoons in Baja California — among the longest migrations of any mammal.

## How do gray whales feed?
By rolling onto their side on the seafloor and suctioning up sediment, then straining small crustaceans such as amphipods through short coarse baleen. They are the only baleen whale to feed mainly this way, and most show more baleen wear on the right side.

## Are gray whales endangered?
The species is listed as Least Concern because the eastern North Pacific population recovered strongly after whaling ended. The western North Pacific population is Critically Endangered, and the North Atlantic population was hunted to extinction centuries ago.

## Why were gray whales called devil fish?
Whalers gave them the name for the ferocity with which mothers defended their calves in the Baja calving lagoons, where hunting was concentrated and the whales fought back hard.

## What do gray whales eat?
The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment. The guide's ecology sections give the prey or forage detail behind that summary.

## Where do gray whales live?
Gray Whales live in North Pacific — eastern population from Mexico to the Arctic, Small, severely depleted western population off Russia. The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment.

## Are gray whales dangerous?
Gray Whales are not generally dangerous to people. The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment. Give wild individuals space and do not corner or handle them.

## How long do gray whales live?
A precise wild lifespan for gray whales is not firmly established in the sources cited on this guide. The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

## How big is a gray whale?
A Gray Whale is about ~15 m. The gray whale migrates up to around 20,000 km a year between Arctic feeding grounds and Mexican calving lagoons, and is the only baleen whale that feeds mainly by rolling on the seabed to filter sediment.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/blobfish): Blobfish — wildlife guide.

## One-line answer
The blobfish (Psychrolutes marcidus) is a deep-sea fish living 600–1,200 m down off Australia and New Zealand; it looks like a normal pinkish sculpin at that depth, and the famous droopy appearance is decompression damage that occurs only when a specimen is hauled to the surface.

## Introduction
The blobfish is best known as the internet's ugliest animal, and that reputation rests entirely on a photograph of a dead, decompressed specimen. In its own habitat — 600 to 1,200 metres down, under pressure roughly 60 to 120 times that at the surface — a blobfish is an ordinary-looking deep-sea sculpin: pinkish, tadpole-shaped, with large eyes and a firm body.

What happens in the photograph is physics. The blobfish has almost no skeleton and gelatinous, low-density flesh, which lets it hover just above the seabed without a swim bladder — and swim bladders are useless at that depth. Bring the animal to the surface and the pressure holding that soft tissue in shape disappears. The face collapses. The animal in the picture is not ugly; it is decompressed, and it is dead.

## Takeaway
A living blobfish does not look like the famous photograph. At depth it is a pinkish, tadpole-shaped sculpin with a firm body and large eyes.

## Takeaway
The droopy face is decompression damage. Removing the animal from 60–120 atmospheres of pressure causes its low-density tissue to lose shape.

## Takeaway
It has almost no skeleton and gelatinous flesh slightly less dense than seawater, which lets it hover above the seabed without expending energy.

## Takeaway
Deep-sea fish cannot use swim bladders — gas-filled organs fail under that pressure — so the blobfish solved buoyancy with body composition instead.

## Takeaway
The specimen in the photograph, nicknamed 'Mr Blobby', was caught during the 2003 NORFANZ research voyage off New Zealand and is held by the Australian Museum.

## Takeaway
It was voted the World's Ugliest Animal in 2013 by the Ugly Animal Preservation Society — a campaign specifically about conservation attention going to charismatic species.

## Takeaway
The blobfish has not been assessed by the IUCN. The main known pressure on it is bycatch in deep-sea bottom trawling, which it has no way of avoiding.

## What does a blobfish actually look like?
At its natural depth, a blobfish looks like what it is: a fathead sculpin. The body is pinkish to pale grey, tapering from a broad head to a narrow tail, with large dark eyes, a wide mouth and pectoral fins held out to the sides. It sits on or hovers just above the seabed. Nothing about it is remarkable, and nothing about it droops.

Almost every photograph in circulation shows something else. Deep-sea fish are usually documented by trawl, and a blobfish brought up from 1,000 metres has undergone a pressure change of roughly 100 atmospheres in minutes. Its tissue is adapted to hold shape under that load and has no structural strength without it — there is barely any skeleton, and the muscle is gelatinous. On deck, the animal slumps. Submersible and ROV footage of living blobfish and close relatives shows normal-looking fish, which is why the correction matters: the ugliness is an artefact of how the specimen was collected.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/blobfish): Blobfish — wildlife guide.

## How does a blobfish survive at 1,200 metres?
By giving up almost everything that makes a fish rigid. Most bony fish control buoyancy with a swim bladder, a gas-filled organ they inflate and deflate. That does not work in the deep sea: at 100 atmospheres the gas is compressed to a fraction of its volume and the energy cost of maintaining it becomes prohibitive. The blobfish has none.

Instead its flesh is a gelatinous mass with density slightly below that of seawater, so the animal is close to neutrally buoyant simply by being made of what it is made of. It can hold position above the seabed without swimming. Bone and muscle are reduced to the minimum, since neither is needed to fight gravity and both are metabolically expensive in an environment with very little food. The result is an animal that spends almost no energy existing — a reasonable strategy where meals are rare and unpredictable, and one that only works because the surrounding pressure does the structural work.

## What does a blobfish eat?
Whatever passes within reach. The blobfish is an ambush feeder that sits on the bottom with its mouth open and takes crustaceans, molluscs, sea urchins, sea pens and carrion drifting down from above. It does not chase prey — pursuit costs energy that a low-metabolism animal in a food-poor environment cannot spare.

This is the standard deep-sea strategy, and it explains the body plan. Large mouth, minimal musculature, no pursuit capability, near-neutral buoyancy: the blobfish is built to wait. The trade-off is that it also cannot avoid anything, which is why bottom trawling is such an effective way of removing it.

## Is the blobfish endangered?
Nobody knows, and that is the honest answer. The IUCN has not assessed Psychrolutes marcidus, and there is no population estimate for it. Deep-sea species are expensive to survey and rarely prioritised, so a great many of them sit in the same position: no data, no assessment, no status.

The pressure that is documented is bycatch. Blobfish live on continental slopes that are trawled for orange roughy, grenadier and other deep-water commercial species, and a bottom trawl takes everything on the seabed regardless of target. A slow-growing, low-fecundity, sedentary animal has no defence against that and no capacity to repopulate quickly afterwards. Deep-sea bottom trawling also destroys the seabed habitat itself — cold-water coral and sponge structures that take centuries to form. The blobfish's real conservation story is not about the blobfish; it is that an entire class of habitat is being removed before the species living in it have been described.

## Why the 'world's ugliest animal' vote actually mattered
In 2013 the Ugly Animal Preservation Society ran a public vote for a mascot, and the blobfish won with around 10,000 votes. The campaign was a joke with a serious argument underneath it: conservation funding and public attention flow overwhelmingly to large, appealing vertebrates, and species that are small, strange-looking or unglamorous get neither, regardless of how threatened they are.

The blobfish proved the point twice over. It became globally famous, and it became famous on the basis of a photograph that misrepresents it — attention without accuracy, which is close to worthless for the animal. The species most in need of protection are frequently the ones nobody has heard of: amphibians, freshwater molluscs, deep-sea fish and invertebrates, which between them account for the overwhelming majority of animal species and a small fraction of conservation spending.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/blobfish): Blobfish — wildlife guide.

## WARN work
WARN publishes free, sourced species education, including for animals that attract attention for the wrong reasons. The blobfish is the clearest example on this site: it is one of the most recognised fish in the world, almost every image of it is misleading, and it has never been formally assessed for extinction risk. Correcting a widely repeated error is worth as much as adding a new fact.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/blobfish): Blobfish — wildlife guide.

## What does a blobfish really look like?
In its natural habitat, 600 to 1,200 metres down, a blobfish looks like an ordinary deep-sea sculpin — pinkish, tadpole-shaped, with a broad head, large dark eyes and a firm body. The famous droopy pink blob is a dead specimen that has been decompressed by being hauled to the surface.

## Why does the blobfish look like that in photos?
Pressure. The blobfish lives under 60 to 120 atmospheres and has almost no skeleton, with gelatinous flesh that holds its shape only because the surrounding water pressure supports it. Bring it to the surface and that support vanishes, so the tissue slumps. The animal in the photograph is decompressed and dead.

## How deep do blobfish live?
Between roughly 600 and 1,200 metres, on the continental slopes off south-eastern Australia, Tasmania and New Zealand. At that depth the pressure is 60 to 120 times greater than at the surface.

## Is the blobfish endangered?
It has not been assessed by the IUCN, so it has no formal conservation status and no population estimate. The main documented pressure is bycatch in deep-sea bottom trawling, which the blobfish — a slow, sedentary bottom-dweller — has no way to avoid.

## What do blobfish eat?
Crustaceans, molluscs, sea urchins, sea pens and carrion. It is an ambush feeder that waits on the seabed with its mouth open rather than pursuing prey, because pursuit costs more energy than a deep-sea environment can reliably supply.

## Where do blobfish live?
Blobfish live on continental slopes off south-eastern Australia, Tasmania and New Zealand, at depths of roughly 600 to 1,200 metres where pressure is 60 to 120 times that at the surface. At that depth they look like ordinary pinkish deep-sea sculpins with firm bodies.

## How big is a blobfish?
Blobfish reach a maximum length of about 30 cm. They have almost no skeleton and gelatinous, low-density flesh that lets them hover just above the seabed without a swim bladder — an adaptation useless at the depths where they live.

## Are smooth-head blobfish dangerous?
Smooth-head blobfish are not generally dangerous to people. The blobfish (Psychrolutes marcidus) is a deep-sea fish living 600–1,200 m down off Australia and New Zealand; it looks like a normal pinkish sculpin at that depth, and the famous droopy appearance is decompression damage that occurs only when a specimen is hauled to the surface. Give wild individuals space and do not corner or handle them.

## How long do smooth-head blobfish live?
A precise wild lifespan for smooth-head blobfish is not firmly established in the sources cited on this guide. The blobfish (Psychrolutes marcidus) is a deep-sea fish living 600–1,200 m down off Australia and New Zealand; it looks like a normal pinkish sculpin at that depth, and the famous droopy appearance is decompression damage that occurs only when a specimen is hauled to the surface. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/poison-dart-frog): Poison Dart Frog — wildlife guide.

## One-line answer
Poison dart frogs are around 200 species of small brightly coloured frogs in the family Dendrobatidae, found in Central and South American rainforests; their toxins are absorbed from a diet of alkaloid-carrying invertebrates, so captive-bred individuals are entirely harmless.

## Introduction
Poison dart frogs are small, brilliantly coloured amphibians of Central and South American rainforests, and almost everything memorable about them is a defence system. The colours are aposematic: a public notice to predators that the frog is not worth eating. The toxin behind that warning is not manufactured by the frog at all — it is sequestered from a diet of mites, ants and other small invertebrates that carry the alkaloids.

That detail has a consequence people find hard to believe. A poison dart frog raised in captivity on fruit flies and crickets is completely non-toxic, and stays that way for life. The poison is a property of the forest, not of the animal.

## Takeaway
Poison dart frogs do not produce their own toxins. They sequester alkaloids from mites, ants and other invertebrates in their diet.

## Takeaway
Captive-bred poison dart frogs fed on fruit flies and crickets are non-toxic, which is why they are kept safely in zoos and private collections.

## Takeaway
Only three of roughly 200 species were ever used to poison blowgun darts, all in the genus Phyllobates.

## Takeaway
The golden poison frog (Phyllobates terribilis) carries around 1 mg of batrachotoxin — among the most potent natural toxins known, and enough to kill 10 to 20 adult humans.

## Takeaway
Their bright colouration is aposematic: a warning signal to predators rather than camouflage. Bold colour is a form of defence in itself.

## Takeaway
Many species show elaborate parental care. Males guard eggs and carry newly hatched tadpoles on their backs to individual pools of water in bromeliads.

## Takeaway
The main threats are habitat loss, the chytrid fungus pandemic and collection for the pet trade. The golden poison frog is Endangered with a very small range.

## Where the poison actually comes from
Poison dart frogs are chemical thieves. They eat mites, ants, beetles and other leaf-litter invertebrates that carry alkaloid compounds, extract those alkaloids, and concentrate them in glands in the skin. Over 800 distinct alkaloids have been identified from dendrobatid skin, and the mix varies with locality because the available prey varies.

The evidence for this is straightforward: frogs raised in captivity on a controlled diet never become toxic, and wild-caught frogs gradually lose their toxicity once removed from the source. It also means a species' danger depends on where it lives. The same species can be significantly toxic in one valley and much less so a short distance away, tracking the invertebrate community rather than the frog's genetics.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/poison-dart-frog): Poison Dart Frog — wildlife guide.

## The golden poison frog
Phyllobates terribilis is the most toxic of the family and one of the most toxic animals known. An adult carries roughly 1 mg of batrachotoxin, a compound that locks sodium channels open and causes cardiac and respiratory failure. That quantity is enough to kill 10 to 20 adult humans, and there is no antidote.

It is also one of only three species genuinely associated with the practice that gave the family its English name. Emberá people of western Colombia wiped dart tips across the frog's back — the frog was not killed — and the darts remained effective for up to two years. The great majority of the roughly 200 dendrobatid species were never used this way and are far less toxic. The golden poison frog itself is Endangered, restricted to a small area of Colombian rainforest under pressure from clearance.

## Fathers who carry their young
Dendrobatid parental care is unusually elaborate for amphibians. Females lay small clutches on the forest floor, and in most species the male guards them, returning to keep the eggs moist. When the tadpoles hatch, he lets them wriggle onto his back and carries them individually to water — usually the small pool held in the centre of a bromeliad, high in a tree.

In some species the mother then returns to each tadpole's pool at intervals and deposits an unfertilised egg for it to eat, since a bromeliad pool contains almost nothing else. That single behaviour turns a frog from an animal that abandons its eggs into one that provisions individual offspring for weeks, and it is why dendrobatids are studied so heavily by behavioural ecologists.

## What threatens them
Habitat loss is the dominant pressure. Dendrobatids are rainforest specialists, many with very small ranges, and clearance for agriculture, logging and mining removes both the forest and the invertebrate community their chemical defence depends on.

The chytrid fungus, Batrachochytrium dendrobatidis, has moved through Central and South American amphibian populations with severe effect, and dendrobatids have not been spared. Collection for the pet trade adds a third pressure on the most desirable species, though captive breeding now supplies much of that demand and has reduced — without eliminating — the incentive to take wild animals. Several species are Endangered or Critically Endangered; many more have never been assessed.

## WARN work
WARN publishes free, sourced species education covering the threats amphibians face — habitat loss, the chytrid pandemic and the exotic pet trade. Amphibians are the most threatened vertebrate class on Earth and receive a small fraction of conservation attention, so accurate free information about them is worth publishing on its own terms.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/poison-dart-frog): Poison Dart Frog — wildlife guide.

## Are poison dart frogs really poisonous?
Wild ones can be. Toxicity varies enormously by species and by locality, because the frogs absorb alkaloids from the invertebrates they eat. The golden poison frog carries enough batrachotoxin to kill 10 to 20 people; many other species are only mildly toxic.

## Why are captive poison dart frogs not poisonous?
Because the toxins come from their diet, not their own biochemistry. Frogs bred in captivity and fed fruit flies and crickets never acquire alkaloids and remain non-toxic for life, which is why they can be safely handled and kept.

## Why are poison dart frogs so brightly coloured?
It is aposematic colouration — a warning signal. Bright, high-contrast patterns advertise toxicity to predators, which learn to avoid them. Being conspicuous is the defence, the opposite of camouflage.

## Were poison dart frogs really used on darts?
Only three species, all in the genus Phyllobates, and only by a small number of Indigenous groups in western Colombia. Dart tips were wiped across a living frog's back and stayed effective for up to two years.

## What do poison dart frogs eat?
They eat mites, ants, beetles and other leaf-litter invertebrates that carry alkaloid compounds, extract those alkaloids, and concentrate them in glands in the skin. Poison dart frogs are around 200 species of small brightly coloured frogs in the family Dendrobatidae, found in Central and South American rainforests; their toxins are absorbed from a diet of alkaloid-carrying invertebrates, so captive-bred individuals are entirely harmless.

## Where do poison dart frogs live?
Poison Dart Frogs live in Central America, Northern South America. Poison dart frogs are around 200 species of small brightly coloured frogs in the family Dendrobatidae, found in Central and South American rainforests; their toxins are absorbed from a diet of alkaloid-carrying invertebrates, so captive-bred individuals are entirely harmless.

## Are poison dart frogs dangerous?
Poison dart frogs are around 200 species of small brightly coloured frogs in the family Dendrobatidae, found in Central and South American rainforests; their toxins are absorbed from a diet of alkaloid-carrying invertebrates, so captive-bred individuals are entirely harmless. Give wild poison dart frogs space; do not corner or handle them.

## How long do poison dart frogs live?
A precise wild lifespan for poison dart frogs is not firmly established in the sources cited on this guide. Poison dart frogs are around 200 species of small brightly coloured frogs in the family Dendrobatidae, found in Central and South American rainforests; their toxins are absorbed from a diet of alkaloid-carrying invertebrates, so captive-bred individuals are entirely harmless. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

## How big is a poison dart frog?
A Poison Dart Frog is about 1.5–6 cm depending on species. Poison dart frogs are around 200 species of small brightly coloured frogs in the family Dendrobatidae, found in Central and South American rainforests; their toxins are absorbed from a diet of alkaloid-carrying invertebrates, so captive-bred individuals are entirely harmless. Conservation status: Habitat loss, chytrid fungus, collection for the pet trade.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/tree-frog): Tree Frog — wildlife guide.

## One-line answer
Tree frogs are over 800 species of arboreal frogs, mainly in the family Hylidae, that climb using adhesive toe pads which work by wet adhesion — a thin layer of mucus creating surface tension against the surface rather than suction.

## Introduction
Tree frogs are not a single group but a life strategy that has evolved repeatedly. The largest family, Hylidae, holds over 700 species, and other families across Africa, Asia and Australia have arrived at the same solution independently. What they share is a set of adaptations for living off the ground: expanded adhesive toe pads, long limbs, light bodies and, in many species, the ability to change colour.

The most photographed of them, the red-eyed tree frog of Central America, is a good illustration of how tree frog defences work. It is green and almost invisible at rest. Disturbed, it flashes red eyes and blue-and-orange flanks — not to frighten a predator away, but to startle it for the fraction of a second the frog needs to jump.

## Takeaway
Tree frogs are not one taxonomic group. Arboreal life has evolved independently in several frog families across the Americas, Europe, Asia and Australia.

## Takeaway
Their toe pads work by wet adhesion, not suction. A thin layer of mucus creates surface tension between pad and surface, which is why a tree frog can climb wet glass but struggles on dry dust.

## Takeaway
The red-eyed tree frog's colours are a deimatic display — a startle response. At rest it is plain green; disturbed, it flashes red eyes and blue flanks to buy a moment to jump.

## Takeaway
Many species change colour, shifting between green and brown according to temperature, light and stress.

## Takeaway
Tree frog eggs are often laid on leaves overhanging water, so hatching tadpoles drop straight in. Some species' embryos can hatch early if they detect a predator attacking the clutch.

## Takeaway
Amphibians are the most threatened vertebrate class on Earth, with around 41% of assessed species at risk from habitat loss, chytrid fungus and climate change.

## How tree frogs stick to glass
The mechanism is not suction, which is the common assumption. A tree frog's toe pad is covered in hexagonal epithelial cells separated by channels, and mucus glands keep a very thin fluid layer across the surface. Adhesion comes from surface tension in that layer — the same force that makes two wet glass slides hard to pull apart — combined with friction from close contact between the pad and the surface.

The channels between cells matter: they drain excess fluid so the layer stays thin enough to grip rather than becoming a lubricant. This is why tree frogs perform well on wet surfaces, where a suction cup would fail, and poorly on dry dusty ones. The design has been studied extensively by materials engineers working on reusable adhesives, and synthetic pads modelled on frog toes now exist in the laboratory.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/tree-frog): Tree Frog — wildlife guide.

## Why the red-eyed tree frog has red eyes
Agalychnis callidryas spends the day asleep on the underside of a leaf, legs tucked in, eyes closed, showing only uniform green. In that posture it is extremely difficult to see. The colours are entirely hidden.

When a predator disturbs it, the frog opens its eyes and leaps, exposing large red irises, blue-and-cream barred flanks and orange feet all at once. This is a deimatic display — a sudden change designed to startle rather than to intimidate. A snake or bird that hesitates for a fraction of a second loses the frog, and a fraction of a second is all the display needs to buy. It works because it is a surprise, which is also why the frog stays plain green the rest of the time.

## Eggs that hatch early to escape
Red-eyed tree frogs and several relatives lay eggs in gelatinous clutches on leaves overhanging ponds. Tadpoles normally hatch after about six or seven days and drop into the water below.

If a snake begins eating the clutch, the remaining embryos can hatch immediately — as early as four days — and drop out of reach. The embryos detect the specific pattern of vibration produced by an attacking predator and distinguish it from wind or rain, and hatching is triggered within seconds. It is one of the clearest documented cases of an embryo making an escape decision before birth, and it comes at a cost: early-hatched tadpoles are smaller and more vulnerable to aquatic predators. The embryo is trading one risk for another.

## WARN work
WARN publishes free, sourced species education. Amphibians are the most threatened vertebrate class on Earth and among the least funded, so free accurate material on how they live and what is happening to them is a genuine gap worth filling.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/tree-frog): Tree Frog — wildlife guide.

## How do tree frogs stick to surfaces?
By wet adhesion. Their toe pads secrete a thin layer of mucus that creates surface tension against the surface, and channels between the pad cells drain excess fluid so the layer stays thin enough to grip. It is not suction, which is why they climb wet glass easily.

## Why does the red-eyed tree frog have red eyes?
As a startle display. At rest the frog is plain green and hidden; when disturbed it opens its eyes and leaps, flashing red irises, blue flanks and orange feet. The sudden change buys the fraction of a second it needs to escape.

## Are tree frogs poisonous?
Most are not dangerously so. Many secrete mild skin toxins or irritants as a defence, and some Australian and South American species produce compounds of pharmacological interest, but tree frogs are not in the same category as poison dart frogs.

## How many species of tree frog are there?
Over 800. The family Hylidae alone contains more than 700 species, and other arboreal frog families across Africa, Asia and Australia have evolved similar adaptations independently.

## What do tree frogs eat?
Tree Frogs eat ~41% — Of assessed amphibian species are threatened with extinction. Tree frogs are over 800 species of arboreal frogs, mainly in the family Hylidae, that climb using adhesive toe pads which work by wet adhesion — a thin layer of mucus creating surface tension against the surface rather than suction.

## Where do tree frogs live?
Tree Frogs live in The Americas, Europe, Asia. Tree frogs are over 800 species of arboreal frogs, mainly in the family Hylidae, that climb using adhesive toe pads which work by wet adhesion — a thin layer of mucus creating surface tension against the surface rather than suction.

## Are tree frogs dangerous?
Tree Frogs are not generally dangerous to people. Tree frogs are over 800 species of arboreal frogs, mainly in the family Hylidae, that climb using adhesive toe pads which work by wet adhesion — a thin layer of mucus creating surface tension against the surface rather than suction. Give wild individuals space and do not corner or handle them.

## How long do tree frogs live?
A precise wild lifespan for tree frogs is not firmly established in the sources cited on this guide. Tree frogs are over 800 species of arboreal frogs, mainly in the family Hylidae, that climb using adhesive toe pads which work by wet adhesion — a thin layer of mucus creating surface tension against the surface rather than suction. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.

## How big is a tree frog?
A Tree Frog is about 2–14 cm depending on species. Tree frogs are over 800 species of arboreal frogs, mainly in the family Hylidae, that climb using adhesive toe pads which work by wet adhesion — a thin layer of mucus creating surface tension against the surface rather than suction. Conservation status: Habitat loss, chytrid fungus, climate change.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/galapagos-tortoise): Galápagos Tortoise — wildlife guide.

## One-line answer
The Galápagos tortoise is the world's largest tortoise, reaching over 400 kg and living beyond 100 years; hunted from an estimated 200,000 animals down to about 3,000 by the 1970s, captive breeding and invasive-species removal have since recovered the population to around 60,000.

## Introduction
The Galápagos tortoise is the largest living tortoise, reaching over 400 kg and routinely living beyond 100 years. It is also one of the very few species on this site whose numbers are going the right way. Whalers and sealers took an estimated 200,000 tortoises through the eighteenth and nineteenth centuries, keeping them alive in ships' holds for months as fresh meat. Introduced goats, rats and pigs then ate the vegetation and the eggs.

By the 1970s roughly 3,000 remained. Captive breeding, invasive-species removal and repatriation have brought the total to around 60,000. Two species were lost along the way, and the rest are still classed as threatened — but this is what conservation looks like when it is funded before the population reaches double digits.

## Takeaway
The Galápagos tortoise is the largest living tortoise, with the heaviest recorded individual at 417 kg.

## Takeaway
It is one of the longest-lived vertebrates, routinely passing 100 years and with credible records beyond 150.

## Takeaway
Whalers and sealers took an estimated 200,000 tortoises, storing them alive in ships' holds because they survive months without food or water.

## Takeaway
Shell shape tracks island vegetation: domed shells on wet islands with ground plants, saddleback shells on dry islands where tortoises must reach up for cactus pads.

## Takeaway
Lonesome George, the last Pinta Island tortoise, died in 2012 — the extinction of an entire species, in public, in the twenty-first century.

## Takeaway
Diego, an Española tortoise repatriated from San Diego Zoo, fathered an estimated 800 offspring and was returned to the wild in 2020 after his species' recovery.

## Takeaway
The population has risen from around 3,000 in the 1970s to roughly 60,000 through captive breeding, goat and rat eradication, and repatriation of juveniles.

## How they were nearly wiped out
Galápagos tortoises can survive for many months without food or water, metabolising fat reserves and the water stored in their bodies. For eighteenth and nineteenth-century whaling and sealing crews, that made them a perfect provision: living meat that needed no feeding and stayed fresh indefinitely. Ships stacked them in their holds by the dozen.

An estimated 200,000 tortoises were taken. Crews preferentially took females, which are smaller and were found lower on the islands, which skewed the surviving populations badly. Settlers then introduced goats, which stripped the vegetation tortoises fed on, and rats and pigs, which ate eggs and hatchlings. Some islands lost their tortoises entirely. By the time serious conservation began in the 1960s, several populations were down to a few dozen animals.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/galapagos-tortoise): Galápagos Tortoise — wildlife guide.

## The recovery, and what made it work
Three things were done, and all three were necessary. Captive breeding centres, most importantly the Fausto Llerena centre on Santa Cruz, incubated eggs and reared juveniles past the age at which rats kill them. Invasive species were removed — the eradication of around 79,000 goats from Isabela and Santiago was one of the largest island restoration operations ever attempted. And juveniles were repatriated to their island of origin once big enough to survive.

The Española population is the clearest result. It was reduced to 14 animals — 12 females and two males, too widely scattered to find each other. A third male, Diego, was located at San Diego Zoo and repatriated. From those 15 animals, the captive programme produced over 2,000 tortoises, and Española now has a self-sustaining wild population. Diego, credited with an estimated 800 offspring, was returned to the island in 2020.

## Why the shells are different shapes
Galápagos tortoise shells come in two broad forms, and the difference is about food. On larger, wetter, higher islands where vegetation grows at ground level, tortoises have domed shells and short necks — there is no need to reach upward, and a domed shell offers more protection.

On drier, lower islands, the available food is largely prickly pear cactus growing well above the ground. Tortoises there have saddleback shells, raised sharply at the front, plus longer necks and legs, allowing them to stretch upward for cactus pads. Darwin noted during the Beagle voyage that the vice-governor claimed to identify a tortoise's island from its shell, and that observation fed into his thinking about how isolated populations diverge. The tortoises are one of the reasons the Galápagos matter to biology at all.

## Lonesome George and what he represented
George was found on Pinta Island in 1971, by which point the island's tortoises had been assumed extinct for decades — goats had stripped the vegetation, and no others were ever found. He was moved to the Santa Cruz breeding centre and became the most famous tortoise in the world, with an international search for a mate that ran for forty years. Females of closely related species were paired with him; no viable offspring resulted.

He died on 24 June 2012, and Chelonoidis abingdonii went extinct with him. What makes George significant is that this happened in full public view, with resources, expertise and global attention available, and it still could not be reversed. He had been the last of his species since before he was found. The lesson conservationists draw from him is the one that runs through every extinction: by the time a species is down to one individual, the outcome was decided decades earlier.

## WARN work
WARN publishes free, sourced species education, including the cases where conservation has demonstrably worked. The Galápagos tortoise recovery — from around 3,000 animals to 60,000 — is one of the strongest available arguments that funded intervention changes outcomes, and it deserves to be as widely known as the losses.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/galapagos-tortoise): Galápagos Tortoise — wildlife guide.

## How long do Galápagos tortoises live?
Routinely over 100 years, with credible records beyond 150. Harriet, a tortoise held in Australia, was around 175 when she died in 2006. They are among the longest-lived vertebrates known.

## How big do Galápagos tortoises get?
The largest recorded individual weighed 417 kg, and large males commonly exceed 250 kg with shells over 1.5 m long. They are the largest living tortoise species.

## Why were Galápagos tortoises hunted?
As ships' provisions. They survive many months without food or water, so whaling and sealing crews stacked them alive in holds as a supply of fresh meat. An estimated 200,000 were taken during the eighteenth and nineteenth centuries.

## Who was Lonesome George?
The last known Pinta Island tortoise, found in 1971 and cared for at the Santa Cruz breeding centre until his death on 24 June 2012. His species, Chelonoidis abingdonii, went extinct with him despite a forty-year international effort to find him a mate.

## Are Galápagos tortoises still endangered?
They remain threatened, but the trend is strongly positive. The total population has risen from around 3,000 in the 1970s to roughly 60,000 through captive breeding, invasive-species eradication and repatriation. Individual species range from Vulnerable to Critically Endangered.

## Why do some have saddle-shaped shells?
To reach food. On dry islands where the main food is prickly pear cactus growing above ground level, tortoises evolved shells raised at the front plus longer necks and legs. On wetter islands with ground vegetation, shells are domed and necks shorter.

## What do Galápagos tortoises eat?
Galápagos tortoises are herbivores eating grasses, leaves, cactus pads, fruits and other vegetation. On drier islands with saddleback shells, tortoises stretch long necks upward to reach prickly pear cactus growing above ground level; on wetter islands domed shells and shorter necks suffice for ground-level plants. Adults can survive many months without food or water — a trait that made them targets as living ship provisions. An estimated 200,000 were taken before conservation began.

## Where do Galápagos tortoises live?
Galápagos tortoises live only on the Galápagos Islands of Ecuador, in habitats from humid highlands to dry lowland scrub. Shell shape tracks island ecology: domed forms on wetter islands with ground vegetation, saddleback forms on drier islands where food grows higher. The population recovered from around 3,000 in the 1970s to roughly 60,000 through captive breeding, invasive-species removal and repatriation, though individual species remain threatened.

## Are Galápagos tortoises dangerous?
Galápagos tortoises are not dangerous to people. These slow-moving giants reach over 400 kg — the heaviest recorded individual weighed 417 kg — and routinely live beyond 100 years. They retreat into their shells when disturbed rather than attacking. Whalers once stacked them alive in ships' holds as provisions because they survive months without food or water. Today they remain threatened but the overall population trend is strongly positive.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/leatherback-turtle): Leatherback Turtle — wildlife guide.

## One-line answer
The leatherback is the world's largest turtle at up to 700 kg, the only sea turtle without a hard shell, and the deepest-diving reptile at over 1,200 m; it feeds almost entirely on jellyfish and is Vulnerable globally, with Pacific subpopulations Critically Endangered.

## Introduction
The leatherback is the largest turtle alive and the strangest. It has no hard shell — the carapace is a leathery, oil-saturated skin over a mosaic of small bone plates — and it is the only surviving member of its family, a lineage separated from all other sea turtles for over 100 million years.

It does things no other reptile does. It dives past 1,200 metres, deeper than most whales. It swims in water near freezing, maintaining a body temperature well above the sea around it. It migrates further than any other reptile, crossing entire ocean basins. And it lives almost entirely on jellyfish — a diet so low in energy that it must eat a huge daily volume, which is precisely why floating plastic is so dangerous to it.

## Takeaway
The leatherback is the largest turtle alive — typically up to about 700 kg, with a record individual at 916 kg.

## Takeaway
It has no hard shell. The carapace is leathery skin over thousands of small interlocking bone plates, ridged into seven longitudinal keels.

## Takeaway
It is the deepest-diving reptile, with a recorded dive of 1,280 m, and one of the deepest-diving air-breathing animals of any kind.

## Takeaway
Leatherbacks maintain a body temperature well above the surrounding water through size, insulating fat and counter-current heat exchange — a strategy called gigantothermy.

## Takeaway
The diet is almost entirely jellyfish. Backward-pointing spines called papillae line the throat and oesophagus so prey cannot slip back out.

## Takeaway
That diet is why plastic is lethal: a floating carrier bag closely resembles a jellyfish, and a swallowed one blocks the gut.

## Takeaway
The global listing is Vulnerable, but East and West Pacific subpopulations are Critically Endangered, having declined by more than 90%.

## The turtle with no shell
Every other sea turtle has a rigid carapace of fused bony plates covered in keratin scutes. The leatherback does not. Its carapace is a layer of tough, oil-saturated skin over a mosaic of thousands of small dermal bones, arranged into seven pronounced ridges running the length of the body.

This is not a deficiency but a specialisation. A rigid shell would be crushed by pressure at depth; a flexible one compresses and recovers. The structure is also lighter and more hydrodynamic, which matters for an animal that swims continuously across ocean basins. The trade-off is that adult leatherbacks have far less physical protection than other sea turtles, which they compensate for with sheer size — a full-grown leatherback has few predators beyond large sharks and killer whales.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/leatherback-turtle): Leatherback Turtle — wildlife guide.

## A warm-blooded reptile, more or less
Leatherbacks feed in water that would immobilise any other reptile, ranging as far north as Norway and Alaska and as far south as New Zealand and Chile. They manage this through gigantothermy: a very large body has a low surface-area-to-volume ratio and loses heat slowly, and the leatherback adds a thick insulating fat layer plus counter-current heat exchangers in the flippers, which recycle heat from outgoing blood into returning blood.

Continuous swimming generates the heat in the first place. A leatherback in cold water can hold a core temperature up to 18°C above the sea around it. It is not endothermy in the mammalian sense — there is no metabolic thermostat — but the practical result is a reptile with access to feeding grounds no other reptile can use.

## Why plastic kills leatherbacks
Jellyfish are around 95% water and provide very little energy, so a leatherback has to consume an enormous daily volume — estimates run to hundreds of kilograms — simply to sustain itself. It feeds by taking in anything gelatinous that drifts within reach, and its throat is lined with backward-pointing papillae specifically to stop soft prey escaping.

A floating plastic bag looks like a jellyfish, feels like a jellyfish, and once swallowed cannot be regurgitated because of those same papillae. It blocks the digestive tract, and the animal starves with a full stomach. Studies of stranded leatherbacks routinely find plastic in a substantial proportion of individuals examined. The feature that makes the leatherback an efficient jellyfish predator is the feature that makes marine plastic specifically, mechanically fatal to it.

## The Pacific collapse
The global Vulnerable listing conceals a much worse regional picture. Atlantic leatherback populations are relatively stable and in places increasing. Pacific populations have fallen by more than 90% and are assessed as Critically Endangered — the East Pacific population is estimated in the hundreds of nesting females.

The causes are bycatch in longline and gillnet fisheries, egg harvesting at nesting beaches, coastal development that destroys nesting habitat, and plastic ingestion. Nesting beaches are the single most tractable point of intervention: protecting a beach and its clutches is cheap relative to fisheries reform and delivers measurable results within a nesting season. Sand temperature also determines hatchling sex, so warming beaches are producing increasingly female-skewed clutches — a slower problem, and a harder one.

## WARN work
WARN publishes free, sourced species education, including on marine plastic and bycatch — the two pressures doing most of the damage to leatherbacks. Understanding why a carrier bag is specifically lethal to this animal, rather than generally bad for the ocean, is the kind of detail that changes behaviour.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/leatherback-turtle): Leatherback Turtle — wildlife guide.

## How big do leatherback turtles get?
Adults typically reach 1.5 to 2 m and up to about 700 kg. The largest verified individual, stranded in Wales in 1988, measured nearly 3 m and weighed 916 kg — the largest turtle ever recorded.

## Why is it called a leatherback?
Because it has no hard shell. Its carapace is a layer of tough, oil-saturated leathery skin over thousands of small bone plates, ridged into seven keels, rather than the fused bony shell every other sea turtle has.

## How deep can leatherback turtles dive?
The deepest recorded dive is 1,280 m, making the leatherback the deepest-diving reptile and one of the deepest-diving air-breathing animals of any kind — deeper than most whales.

## What do leatherback turtles eat?
Almost entirely jellyfish and other gelatinous plankton. Because jellyfish are around 95% water, a leatherback must eat an enormous daily volume, and backward-pointing spines in its throat stop soft prey slipping back out.

## Why are plastic bags dangerous to leatherbacks?
A floating bag closely resembles a jellyfish, and the backward-pointing papillae that stop jellyfish escaping also make regurgitation impossible. Swallowed plastic blocks the gut, and the turtle starves.

## Are leatherback turtles endangered?
Globally they are listed as Vulnerable, but that masks severe regional decline. East and West Pacific subpopulations have fallen by more than 90% and are Critically Endangered, driven by fisheries bycatch, egg harvesting, coastal development and plastic.

## Where do leatherback sea turtles live?
Leatherback Sea Turtles live in All tropical and temperate oceans, Feeds as far north as Norway and Alaska. The leatherback is the world's largest turtle at up to 700 kg, the only sea turtle without a hard shell, and the deepest-diving reptile at over 1,200 m; it feeds almost entirely on jellyfish and is Vulnerable globally, with Pacific subpopulations Critically Endangered.

## How long do leatherback sea turtles live?
A precise wild lifespan for leatherback sea turtles is not firmly established in the sources cited on this guide. The leatherback is the world's largest turtle at up to 700 kg, the only sea turtle without a hard shell, and the deepest-diving reptile at over 1,200 m; it feeds almost entirely on jellyfish and is Vulnerable globally, with Pacific subpopulations Critically Endangered. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/tuatara): Tuatara — wildlife guide.

## One-line answer
The tuatara is a New Zealand reptile that is the only surviving member of the order Rhynchocephalia, a lineage separate from lizards and snakes for around 250 million years; it lives over 100 years, thrives at 16–21°C, and survives only on predator-free islands.

## Introduction
The tuatara looks like a lizard and is not one. It is the only surviving member of the order Rhynchocephalia, a lineage that separated from all other reptiles roughly 250 million years ago — before the first dinosaurs. Every lizard and snake alive today, from a gecko to a python, is more closely related to every other lizard and snake than any of them is to a tuatara.

It is also biologically odd in ways that follow from that isolation. It has a functioning light-sensitive third eye on top of its head in juveniles, two rows of upper teeth that a single lower row bites between, the lowest preferred body temperature of any reptile, and a lifespan that can pass a century. It survives on around 30 New Zealand offshore islands, and essentially nowhere that has rats.

## Takeaway
Tuatara are not lizards. They are the only living members of Rhynchocephalia, an order that diverged from the lizard and snake lineage around 250 million years ago.

## Takeaway
They have a parietal or third eye on top of the head — complete with lens, retina and nerve connection — visible in hatchlings and covered by scales as they mature.

## Takeaway
The teeth are fused to the jaw rather than set in sockets, arranged as two upper rows and one lower row that shears between them.

## Takeaway
They prefer body temperatures of 16 to 21°C, lower than any other reptile, and remain active at temperatures where most reptiles cannot function.

## Takeaway
Tuatara live over 100 years and mature very slowly, breeding for the first time at around 10 to 20 years and laying eggs only every two to five years.

## Takeaway
Sex is determined by incubation temperature, so warming nest sites skew clutches male — the opposite direction to most reptiles.

## Takeaway
Introduced Pacific rats eliminated them from the New Zealand mainland. They survive on around 30 offshore islands and in fenced sanctuaries.

## Why the tuatara is not a lizard
The resemblance is superficial. Tuatara belong to Rhynchocephalia, a reptile order that was widespread and diverse in the Mesozoic and is now reduced to a single genus on a handful of islands. The split from Squamata — lizards and snakes — dates to roughly 250 million years ago, in the Triassic, before dinosaurs became dominant.

The anatomical differences are substantial. Tuatara retain a complete diapsid skull with two temporal openings and a solid bony arch that lizards have lost, giving the skull a rigidity lizards do not have. Their teeth are acrodont, fused directly to the jawbone rather than sitting in sockets, and are not replaced when worn — an old tuatara has blunt teeth and switches to softer prey. They have no external ear opening and, uniquely among reptiles, no copulatory organ; mating is by cloacal contact, as in most birds.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/tuatara): Tuatara — wildlife guide.

## The third eye
A hatchling tuatara has a visible parietal eye on top of its head: a small structure with its own lens, retina and nerve connection to the brain, covered by a translucent scale. It is not used to form images. Over the first few months, scales and pigment grow over it and it becomes invisible from outside, though it remains connected internally.

Parietal eyes exist in some lizards and frogs too, but the tuatara's is the most fully developed in any living animal. Its function is thought to involve regulating circadian rhythm and seasonal cycles by measuring day length, and possibly thermoregulation — a tuatara that can sense sunlight on the top of its head has information about basking conditions without needing to look up. It is a genuine window onto a sensory arrangement most vertebrate lineages abandoned.

## Living slowly, and what that costs
Everything about tuatara biology runs at low speed. They have the lowest metabolic rate of any reptile studied, are active at temperatures where other reptiles are torpid, grow until around 35 years old, and breed for the first time somewhere between 10 and 20. Females lay a clutch only every two to five years, and eggs incubate in the ground for 12 to 15 months — one of the longest incubation periods of any reptile.

That pace is well suited to a cool, stable, predator-free island and catastrophically unsuited to anything else. A population that replaces itself this slowly cannot absorb losses. Introduced Pacific rats, brought by early Polynesian settlers, ate eggs and hatchlings faster than tuatara could produce them, and cleared them from mainland New Zealand entirely. It is the kākāpō problem in reptile form.

## Conservation and the temperature problem
Tuatara are listed as Least Concern, which reflects a stable total population rather than security. They persist on around 30 offshore islands, several of which have had rats eradicated specifically to allow reintroduction, plus fenced mainland sanctuaries such as Zealandia in Wellington, where tuatara bred in the wild on the mainland in 2009 for the first time in around 200 years.

The emerging threat is temperature. Tuatara have temperature-dependent sex determination running in the unusual direction: warmer nests produce males. Sustained warming at nesting sites would push populations toward a male bias and eventually toward reproductive failure. Because the islands are small and fixed, the animals cannot shift range in response. Management options — shading nest sites, translocation to cooler islands — exist, but they require the kind of continuous funded monitoring that a Least Concern listing tends not to attract.

## WARN work
WARN publishes free, sourced species education. The tuatara is one of the clearest cases of a species that looks secure on paper and is not: a single surviving lineage, on small islands, dependent on continuing invasive-predator control that has to be funded every year without a crisis to prompt it.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/tuatara): Tuatara — wildlife guide.

## Is a tuatara a lizard?
No. Tuatara are the only surviving members of the order Rhynchocephalia, which separated from lizards and snakes around 250 million years ago. Every lizard alive is more closely related to every snake than either is to a tuatara.

## Does the tuatara really have a third eye?
Yes. Hatchlings have a visible parietal eye on top of the head with its own lens, retina and nerve connection. It becomes covered by scales within months but stays connected internally, and is thought to help regulate circadian and seasonal rhythms.

## How long do tuatara live?
Over 100 years, and possibly considerably more. They grow until around 35 and breed for the first time between 10 and 20 years old. Henry, a tuatara at Southland Museum, fathered offspring at an estimated age of 111.

## Where do tuatara live?
Only in New Zealand, on around 30 offshore islands plus fenced mainland sanctuaries. Introduced Pacific rats eliminated them from the mainland; islands cleared of rats are the reason they still exist.

## Are tuatara endangered?
They are listed as Least Concern, but that reflects a stable managed population rather than a secure one. They depend entirely on continued predator control, and temperature-dependent sex determination makes them vulnerable to warming at nesting sites.

## Why do tuatara prefer cold temperatures?
They are adapted to New Zealand's cool climate and have the lowest optimal body temperature of any reptile, around 16 to 21°C. They remain active at temperatures at which most reptiles become torpid, and overheat at temperatures many reptiles prefer.

## Are tuataras dangerous?
It has a functioning light-sensitive third eye on top of its head in juveniles, two rows of upper teeth that a single lower row bites between, the lowest preferred body temperature of any reptile, and a lifespan that can pass a century. Give wild tuataras space; do not corner or handle them.

## What do tuatara eat?
Tuatara feed on invertebrates and other small prey, using acrodont teeth fused directly to the jawbone rather than sitting in sockets. Teeth are not replaced when worn — an old tuatara develops blunt teeth and switches to softer prey. They hunt at night on predator-free New Zealand islands, remaining active at body temperatures of 16–21°C where most reptiles are torpid.

## How big is a tuatara?
A Tuatara is about Up to about 80 cm including tail. The tuatara is a New Zealand reptile that is the only surviving member of the order Rhynchocephalia, a lineage separate from lizards and snakes for around 250 million years; it lives over 100 years, thrives at 16–21°C, and survives only on predator-free islands.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/skink): Skink — wildlife guide.

## One-line answer
Skinks are over 1,700 species of lizards in the family Scincidae, found on every continent except Antarctica; they are recognisable by smooth overlapping scales and reduced limbs, and limb loss has evolved independently many times within the family.

## Introduction
Skinks are the lizards most people have seen without registering what they were looking at: smooth, glossy, fast-moving animals with small legs and long tails, sliding through leaf litter. The family Scincidae holds over 1,700 species, making it the second largest lizard family after geckos, and it is distributed across every continent except Antarctica.

What makes skinks scientifically interesting is the range within the family. Some have four fully functional limbs. Some have tiny vestigial ones. Some have none at all and move exactly like snakes. Limb reduction has evolved independently many times within Scincidae, which makes the family a working demonstration of the transition that produced snakes — happening repeatedly, in front of us.

## Takeaway
Scincidae contains over 1,700 species, second only to geckos among lizard families, and occurs on every continent except Antarctica.

## Takeaway
Skinks have smooth, overlapping scales underlaid by bony plates called osteoderms, which is what gives them their characteristic polished look.

## Takeaway
Limb reduction has evolved independently many times within the family, producing everything from four-legged to entirely legless species.

## Takeaway
Most skinks can shed their tail — caudal autotomy — and the detached tail continues thrashing to hold a predator's attention while the lizard escapes.

## Takeaway
Around 45% of skink species give birth to live young instead of laying eggs, and some provide a genuine placenta-like connection to developing embryos.

## Takeaway
The blue-tongued skink of Australia flashes a bright blue tongue as a startle defence, and is one of the largest members of the family.

## Takeaway
Most skinks are Least Concern, but island endemics — particularly in New Zealand, Mauritius and the Caribbean — include some of the most threatened reptiles on Earth.

## How skinks became snake-shaped, repeatedly
Within Scincidae you can find the entire sequence from a normal four-limbed lizard to a functionally legless one. Some species have full limbs. Others have shortened limbs with reduced digit counts. Others have limbs reduced to small flaps. Several genera, including Australian Lerista, contain species at multiple points along that gradient — sometimes closely related species differing chiefly in how many toes they have.

The driver appears to be burrowing and moving through dense litter or loose sand, where limbs get in the way and lateral undulation is more efficient. Because this has happened independently in many skink lineages, the family gives evolutionary biologists something rare: repeated instances of the same major body-plan transition, at different stages, in living animals. Much of what is understood about how snakes lost their legs comes from studying skinks that are currently doing it.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/skink): Skink — wildlife guide.

## The tail that fights on without them
Most skinks can detach their tail deliberately at a fracture plane built into the vertebrae. Muscles contract to break the tail off and simultaneously seal the blood vessels, so blood loss is minimal. The severed tail then thrashes vigorously for minutes, driven by stored energy in the muscle tissue.

The purpose is to give a predator something to commit to. A cat or bird that grabs the moving tail is holding the wrong part of the animal. Many juvenile skinks have brightly coloured — often blue — tails specifically to draw attacks toward the expendable end. The cost is real: the tail stores fat, and a regrown one is shorter, supported by cartilage rather than bone, and cannot be shed again at the same place. Skinks that have dropped a tail have measurably reduced survival and breeding success until it regrows.

## Live birth, and something close to a placenta
Around 45% of skink species are viviparous — they give birth to live young rather than laying eggs. This has evolved independently many times within the family, generally in cooler climates and at higher altitudes, where retaining developing embryos inside the body allows a female to control their temperature by basking.

Some species have gone considerably further. In several skinks the eggshell is reduced to nothing and the female develops a placenta-like structure that transfers nutrients directly to embryos, an arrangement functionally similar to that of a mammal and evolved entirely separately. The Australian genus Pseudemoia includes some of the best-studied examples. For anyone interested in how reproductive strategies change, skinks offer the same advantage they offer for limb loss: the full range of intermediate stages, alive and available to study.

## The skinks in trouble
As a family, skinks are doing reasonably well — most species are Least Concern, and many thrive in gardens and disturbed habitats. The exceptions follow a familiar pattern: island endemics with small ranges and introduced predators.

New Zealand's skinks have been reduced by rats, stoats and cats, with several species now confined to predator-free islands or fenced sanctuaries. Mauritius has lost skink species outright to introduced predators and retains others in single-island populations. Caribbean skinks have been hit hard by mongooses introduced to control rats — an intervention that failed at its purpose and devastated the native reptiles instead. The threats are the standard ones for island reptiles, and so are the solutions: predator eradication, translocation to safe islands, and fenced sanctuaries.

## WARN work
WARN publishes free, sourced species education, including for the animal groups that receive least attention. Reptiles are consistently underfunded relative to their extinction risk, and island skinks — small, unglamorous and often confined to a single location — are among the least visible threatened animals anywhere.

## Donation hook
If this guide helps you understand wildlife and the pressures it faces, a gift to WARN supports habitat protection and free public education in our partner countries.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/skink): Skink — wildlife guide.

## What is a skink?
A lizard in the family Scincidae, which contains over 1,700 species — the second largest lizard family. Skinks are recognisable by smooth overlapping scales, often reduced limbs, and a long tail, and are found on every continent except Antarctica.

## Are skinks lizards or snakes?
Lizards. Some legless skink species look and move like snakes, but they are true lizards with eyelids and external ear openings, both of which snakes lack. Limb reduction has evolved independently many times within the family.

## Do skinks lose their tails?
Most can, by caudal autotomy. Muscles break the tail at a built-in fracture plane and seal the blood vessels, and the detached tail thrashes for minutes to distract the predator. A regrown tail is shorter and supported by cartilage rather than bone.

## Are skinks venomous or dangerous?
No. Skinks are not venomous and pose no danger to people. Larger species such as blue-tongued skinks can deliver a firm bite if handled roughly, but they are otherwise harmless and are commonly kept as pets.

## Do skinks lay eggs or give birth?
Both, depending on species. Around 45% of skinks give birth to live young, an adaptation that has evolved repeatedly in cooler climates. Some species have gone as far as developing placenta-like structures that feed embryos directly.

## Where do skinks live?
Skinks live in Every continent except Antarctica. Skinks are over 1,700 species of lizards in the family Scincidae, found on every continent except Antarctica; they are recognisable by smooth overlapping scales and reduced limbs, and limb loss has evolved independently many times within the family.

## How long do skinks live?
A precise wild lifespan for skinks is not firmly established in the sources cited on this guide. Skinks are over 1,700 species of lizards in the family Scincidae, found on every continent except Antarctica; they are recognisable by smooth overlapping scales and reduced limbs, and limb loss has evolved independently many times within the family. Where longevity figures appear in the literature they vary by region, sex and whether animals are wild or captive.


World Animal Rescue Network (https://worldanimalrescuenetwork.org/wildlife-guides/snapping-turtle): Snapping Turtle — wildlife guide.

## One-line answer
Snapping turtles are two North American freshwater species — the common snapping turtle and the larger alligator snapping turtle, which lures fish with a worm-shaped appendage on its tongue; both are far less dangerous than their reputation, with bite forces well below those of a large dog.

## Introduction
Two North American turtles share the name. The common snapping turtle is widespread across eastern and central North America, aggressive on land and largely inoffensive in water. The alligator snapping turtle is a much larger, heavily armoured animal of southern rivers, and one of the few reptiles anywhere that fishes with a lure — a pink, worm-shaped appendage on its tongue that it wriggles inside an open mouth.

Both are surrounded by exaggeration. The claim that a snapping turtle can bite through a broom handle or sever fingers has been tested and is false: measured bite forces are substantial for a turtle and unremarkable compared to a large dog. The bites that do happen almost always occur on land, where a turtle out of its element and unable to retreat into its shell has nothing else to defend itself with.

## Takeaway
Two species share the name: the common snapping turtle (Chelydra serpentina) and the much larger alligator snapping turtle (Macrochelys temminckii).

## Takeaway
The alligator snapping turtle is among the heaviest freshwater turtles in the world, with verified wild animals around 100 kg.

## Takeaway
It hunts using a lingual lure — a pink, worm-like appendage on the tongue that it wriggles while lying motionless with its mouth open.

## Takeaway
Measured bite force for a common snapping turtle is around 209 newtons. A large dog exceeds 1,000. The broom-handle claim is false.

## Takeaway
Snapping turtles are aggressive on land because they cannot withdraw fully into their small plastron; in water they almost always retreat.

## Takeaway
The common snapping turtle is Least Concern and widespread. The alligator snapping turtle is Vulnerable, hit by decades of commercial harvesting for meat.

## Takeaway
Road mortality is a major pressure. Females crossing roads to reach nest sites are killed disproportionately, which removes exactly the animals a slow-breeding population cannot spare.

## Fishing with a tongue
The alligator snapping turtle is one of very few reptiles that uses a lure to hunt. It rests motionless on the river bottom, algae-covered and effectively indistinguishable from a rock, and holds its mouth wide open. On the floor of the mouth sits a small pink appendage on the tongue that the turtle wriggles in a convincing imitation of a worm.

A fish that comes to investigate is taken by a strike fast enough that high-speed footage is needed to follow it. The behaviour lets an extremely heavy, slow animal catch fast prey without pursuing anything, and it is the same evolutionary solution reached independently by anglerfish and some snakes. Alligator snappers also actively forage at night, taking fish, molluscs, carrion and occasionally other turtles, so the lure is one tactic rather than the whole strategy.