- [Narrator] Inside a hollow tree, this pine marten mom has mouths to feed.

Two kits were born in mid-April and are now almost two weeks old.

Utterly dependent on their mother, they must stay inside their tree house for another month.

Until the young pine marten leave home, mom is their only contact with the outside world.

(birds chirping) (marten cooing) By day, she grooms and feeds them and gets some well-earned rest.

Come evening, she leaves for a night hunting in the woods.

(kits squeaking) The kits are left to mind themselves.

And like youngsters of all kinds, keeping quiet is a big challenge.

Little do they know, but these kits are critical to the future of their kind in Ireland.

(kits growling) For four weeks, the pine marten mom has been feeding milk to her kids, but soon they must make the move to solid food.

(birds chirping) For the first time, she brings home prey that they will haunt during their future lives in the wild.

At first, the kits don't quite know what to do.

Is it for eating or playing?

(kits growling) They soon figure it out and are hungry for more.

At four months, the marten kits make their first expeditions out into the real world.

(kits growling) These carefree weeks of their very first summer are precious, as most Martins survive for only five or six years.

Like youngsters of all kinds, the harsh realities of life seem very distant when there's games to be played.

(kits growling) As summer draws to a close, their mother will push them away to live on their own.

These few weeks of play and pleasure will never happen again.

(birds chirping)