[David] Incredible ingenuity, dedication, and extraordinary teamwork.

This is what it takes to be a parent on our planet.

(cub mewing) (music) Meet the hardworking parents raising their families, doing all they can to protect, (sheep bleating) and provide for the next generation.

The future is everything.

This is "Parenthood."

- [Narrator] Every city has its share of savvy hustlers.

(music) And it turns out pigeons are the epitome of street smart, social, intelligent, agile, and tough.

How did the humble pigeon master the urban hustle?

(music) Over 50 years, five tigers let one filmmaker into their lives.

- [Narrator 1] I wasn't a scientist or a naturalist, or a conservationist.

I was simply a filmmaker who fell in love with the beauty of this place, and its wild tigers.

(tiger growling) - [Narrator] But there's nothing simple about this story.

- [Narrator 1] For the first time, I'm able to piece together the story of five tigresses' matriarchal clan.

- [Narrator] What comes next is the tale of a resilient animal dynasty, and the advent of a new dawn for the tigers of India.

- [Narrator 1] I can only hope that this story will help others fight for their future.

(jungle noises) - Just think I knew her when she was three years old.

(jungle noises) And look at the old lady now.

She's the only one now of the old days, that I really, really know.

She was a spunky little girl as she grew up.

Gremlin today has become the top ranking female.

- [Narrator 2] At 54 years old, Gremlin is the oldest chimp mother ever recorded in Gombe.

- I think what's amazing about the Gombe study, it's now in its 65th year.

We have been able to look back over the records of this unbroken study, one of the three longest studies of any animals in the world.

We can start asking questions that you can't ask from a short term study.

There's so much we don't know yet.

- [Narrator 2] Now, a multi-generational saga of female power and motherhood has come to light.

- So although it's a male-dominated society, the females play a very important role.

Well, if I could have a discussion with Gremlin, I would say, "I wonder if you understand how much you've taught us about courage, about motherhood, and about grief."

I'd say, "Thank you, because you have given us so much."