There aren't a lot of them, and they don't breed quickly or successfully.

Scientists estimate that a chick hatches from only a third of all the kakapo eggs lead, but they're making a slow comeback.

Yeah, on a remote island off the south coast of New Zealand, live the world's heaviest and only flightless parrot.

The Kochs oppose wings are too short for the bird to get airborne, so instead they rely on their beak and claws to climb up trees they live to around 60 years.

But despite ones being one of New Zealand's most abundant birds today, they're one of the country's most rare and threatened species.

The cock up or used to be one of the most common words in New Zealand.

But when people arrive, things started to go wrong.

People hunted them for food.

People cleared the forests which they live in, and people brought mammals with them, which predated the Kharkiv.

Also, things like cats, dogs and Stokes kakapo almost became extinct.

Andrew Digby, as part of the Kakapo Recovery Program established in 1995 to bring this charismatic bird back from the brink of extinction only breeds about every three years or so.

And that's when a particular type of tree produces lots and lots of fruit, and they breed in response to them.

Today, Andrew's team are on the island to check on the kakapo they have electronically tagged.

Finding these supremely camouflaged birds is not an easy task.

Every character has a transmitter on it, for example, so we can track where it is and what his activity is.

We optimize the feeding, so each car couple gets his own individual diet, their light amount of food for that particular bird.

We have scales at the feeding station so we can weigh the car.

People know how much it is, and they have a lockable lid so we can make sure that only that car couple and not the other car couple get into that particular feeding station.

Since the recovery program began in the nineties, the population has quadrupled.

Today, over 200 birds roam the islands.