Thai customs have confiscated 21 rhino horns with an estimated value of nearly $US5 million ($6.6 million) in the biggest such seizure in Thailand for years, officials said on Tuesday.

Tasmanian devils with tumours the size of golf balls have had their cancerous growths disappear, after scientists successfully trialled a new way to kick-start the animals' immune system.

Cheetahs are on the precipice of extinction, yet small homeless mutts - found on the street - may be one of the keys to their survival.

"It is altering the structure and function of natural ecosystems, and affecting heritage, economic activity and human wellbeing."

Wildlife prices are tumbling in South Africa as game breeders are squeezed by restrictions imposed on trophy hunting after Cecil the lion was killed, and the worst drought on record has forced farmers to sell animals.

There's an old saying that elephants never forget. You also can say they almost never sleep.

Violence in El Salvador has reached crisis levels in recent years.

Restricting the amount of greenery growing beside the state's waterways will have a detrimental effect on the environment while failing to meet its goal of reducing bushfire threats, top waterway ecosystem scientists have warned.

Scientists are criticising the Australian government for its plan to unleash herpes on carp.

Six ocean hot spots that teem with the biggest mix of species are also getting hit hardest by global warming and industrial fishing, a study has found.

Boston: Woolly mammoths - or, at least, animals with very similar DNA - could be brought back from extinction within two years, say scientists behind a ground-breaking resurrection project.

The amount of oxygen in oceans around the world has declined, a long-predicted result of climate change, scientists have revealed.

China has ordered an investigation after online images showed officials holding a lavish banquet of meat from the endangered pangolin, the most trafficked mammal on earth.

Meet Taronga Zoo's newest addition  - one of the world's tiniest and rarest primates, a mohawk-sporting baby cotton-top tamarin.

An adorable baby red panda who suffered horrific neck injuries has a second lease on life thanks to a cuddly toy and a Sydney zookeeper.

It was a tough call as to who had the more enviable job. The answer depended which end of a large and potentially dangerous predator you would rather be working on: the head (read canine teeth) or the tail (read anal gland).

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Growing up in Pakistan, my favourite show was Flipper. Living in a city a thousand kilometres from the nearest ocean, it was the most I knew about our beautiful dolphin friends.

If you want to save an elusive porpoise from being wiped out forever, why not try a team of dolphins, specially trained by the US Navy to detect undersea mines?

He was quite the catch: young, good looking and fit. Spotted lounging in a tree not far from the edge of a road, this koala was a welcome addition to a study which hopes to shed light on why the Somers koala population is in decline.

To the uninitiated they don't look like much to get excited about. Perhaps the only intriguing thing is that their bulbous bodies are a milky-white, rather than dark brown or black. But these tadpoles are special.

China has announced that it was banning all commerce in ivory by the end of 2017, a move that would shut down the world's largest ivory market and could deal a critical blow to the practice of elephant poaching in Africa.

Opportunistic whales have forced researchers to reconsider whether long-line fishing in Australia's southern waters is as eco-friendly as first thought.

Numbers of migrating birds travelling from the Arctic to Botany Bay are dwindling.

Taronga Zoo opens Squirrel Monkey Jungle Walk

The tallest species on the planet is much rarer than previously understood.

Venom from two iconic Australian species could be behind the development of new treatments for diabetes, which affects around 1.7 million Australians.

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The baby pygmy marmoset stolen from a Helensburgh wildlife park has been found, but Gomez and Sophia are still missing.

• UPDATED

The baby pygmy marmoset stolen from a Helensburgh wildlife park has been found, but Gomez and Sophia are still missing.

Pauline Hanson is copping flak for taking her senators to a healthy part of the Great Barrier Reef in an effort to disprove claims the icon is dying.