There are animals we have already said goodbye to that were never quite ready to leave.
A tiger has returned to a landscape in Kazakhstan after more than 70 years without one.
A bird in New Zealand was declared extinct — twice — before being found alive.
A butterfly disappeared from Britain entirely, then came back.
And on islands in the Pacific, tiny snails that had vanished from the wild are being returned to their homes.
None of these is the same story.
That is precisely what makes them worth telling.
Because when we talk about animals being “lost”, we can mean several very different things.
Sometimes a species is genuinely extinct.
Sometimes it has disappeared from a country or habitat but survives elsewhere.
Sometimes scientists believe it is gone altogether — until someone finds one alive.
And sometimes conservationists manage to intervene before the last animals disappear.
The difference between those stories can be measured in millions of years, thousands of miles, or a creature small enough to sit on your fingertip.
The tiger coming home
On 31 July, an adult female Amur tiger named Umit was released into Kazakhstan's Ile-Balkhash State Nature Reserve.
It was the first time in more than 70 years that a tiger had been released into the wild in Kazakhstan after the species disappeared from the country.
Umit had arrived from Russia earlier in the year alongside three other Amur tigers and spent time in an adaptation enclosure before conservationists judged her ready for independent life.
She is not a Caspian tiger.
That species is extinct.
She is an Amur tiger, being used as part of a programme intended to restore tigers to part of their historic Central Asian range.
That distinction matters.
Umit does not mean that an extinct species has suddenly returned.
She represents something more cautious — and perhaps more interesting.
A species that disappeared from a landscape is being given the opportunity to occupy it again.
The programme is only beginning.
Whether a self-sustaining population can eventually be established remains to be seen.
For now, there is simply a tiger where there have been no wild tigers for generations.
Sometimes recovery starts with one animal.
The bird that refused to stay extinct
Few animals have a more extraordinary relationship with the word “extinct” than New Zealand's takahē.
The flightless bird was believed to have disappeared in the nineteenth century.
Then it was rediscovered in 1948.
It had survived in the remote Murchison Mountains, largely protected by the isolation of its habitat.
But surviving discovery did not mean the takahē was safe.
Introduced predators, competition and habitat pressures continued to threaten the population.
Today, there are just over 500 takahē.
That is still dangerously small.
But it is also a remarkable change from a species that the world had already written off.
And the recovery programme is still moving.
In May this year, eight takahē were moved from a trial site in Kahurangi National Park to a new sanctuary at Onetahua in Golden Bay after conservationists concluded that the original site was not supporting the birds as well as hoped.
That might sound like failure.
It isn't necessarily.
The conservation team learned that food availability, breeding success and adult survival were not what they had expected.
Those lessons are now being used to choose better places for future populations.
Recovery is not always a straight line.
Sometimes saving a species means discovering what doesn't work — and trying somewhere else.
A butterfly that came back to Britain
The large blue butterfly is much smaller than a tiger.
Its story is no less extraordinary.
The species became extinct in Britain in 1979.
But the story did not end there.
Scientists discovered that the butterfly's life cycle was far more complicated than it appeared. Its caterpillars spend much of their development inside the nests of red ants, where they feed on ant grubs.
Understanding that relationship helped conservationists understand why the butterfly had disappeared.
It wasn't enough to protect a patch of grassland.
The landscape had to work for the ants, the plants and the butterfly.
The large blue was subsequently reintroduced to Britain from continental Europe.
Butterfly Conservation now says it has been successfully reintroduced to more than 11 sites.
Recent monitoring has shown just how dramatic that recovery has been: the organisation reports that large blue numbers have increased by 1,866 per cent since 1983.
That number needs context.
The butterfly began from an extraordinarily low baseline after its extinction in Britain.
But the direction matters.
A species that once vanished from the country is flying here again.
The bumblebee Britain lost
The short-haired bumblebee offers another British version of the same story.
It was declared extinct in Britain in 1988.
Unlike the large blue, its disappearance was not caused by one strange ecological relationship that scientists eventually unravelled.
Habitat loss and changes to the countryside played a major part.
In 2012, conservationists began an ambitious attempt to bring the species back, using queens from Sweden and working to restore suitable habitat in the Dungeness and Romney Marsh area of Kent.
The project has now been running for more than a decade.
It is a useful reminder that reintroduction is not simply a matter of putting an animal somewhere and hoping for the best.
The landscape has to be ready.
Food has to be available.
The conditions that caused the original decline have to be addressed.
Otherwise, all that has been achieved is moving an animal into the same problem it left.
The snails that came back glowing
Then there are the Partula snails.
They are not the sort of animal most people picture when they hear the word conservation.
They are tiny.
They are easy to overlook.
And several species were wiped out in the wild after invasive predators were introduced to their island homes in French Polynesia.
But conservationists managed to rescue some of the last surviving animals and establish breeding programmes.
In 2025, the Zoological Society of London and its partners reintroduced just under 7,000 zoo-bred Partula snails to four islands.
Some were described as “glow-in-the-dark” snails because conservationists use harmless fluorescent marking techniques to help monitor them.
It is an almost absurdly small scale on which to conduct a conservation triumph.
A snail.
A leaf.
An island.
Thousands of animals that most people would struggle to identify.
And yet the principle is the same.
A species had disappeared from the wild.
People refused to accept that as the final chapter.
The animal that was found after we thought it was gone
Sometimes conservation doesn't bring an animal back.
Sometimes we discover that it was there all along.
The takahē is one example.
The Lord Howe Island stick insect is another.
For decades, the insect was considered extinct after rats devastated its native population on Lord Howe Island.
Then, in 2001, living insects were found on Ball's Pyramid, a steep volcanic sea stack off the Australian island.
It was an extraordinary discovery.
The animal people had written off was still alive.
But finding a few survivors was only the beginning.
Captive breeding programmes have since worked to increase the population and develop the possibility of returning the species to Lord Howe Island itself.
The lesson is almost painfully simple:
Sometimes we don't know something is gone until we look properly.
Not everything has been saved
It would be easy to turn these stories into a comforting claim that nature is recovering everywhere.
It isn't.
The threats that pushed these animals towards extinction have not magically disappeared.
Habitat is still being destroyed.
Invasive species still spread.
Climate change is altering ecosystems.
Pollution still kills wildlife.
Some species really are gone, and there is no conservation programme waiting to bring them back.
That makes these stories more meaningful, not less.
The point is not that everything will be all right.
The point is that decline is not always destiny.
The large blue butterfly is proof that a species can disappear from a country and return.
The takahē shows that a species can be declared extinct and still survive.
The Partula snails show that even tiny animals can receive decades of painstaking conservation effort.
The Lord Howe Island stick insect shows that “extinct” can occasionally be overturned by discovery.
And Umit, walking through Kazakhstan, represents something different again.
A species can disappear from a landscape without disappearing from the world.
Sometimes there is still a way home.
Perhaps that is the most hopeful thing about these animals.
Not that we have solved the biodiversity crisis.
We haven't.
Not that extinction can always be reversed.
It can't.
But that there are moments when the story changes direction.
A bird we thought was gone is still calling from the mountains.
A butterfly we once lost is flying over British grassland.
Tiny snails are being returned to Pacific islands.
An insect thought extinct is being bred for a return to its home.
And a tiger is walking through Kazakhstan again.
None of them guarantees what comes next.
But none of them is gone.
And sometimes, for a species standing at the edge of history, still here is a very good place to begin.