23/11/2015 Newsround

Novak Djokovic has become the first player to win four

He beat Roger Federer in the final in London.

Djokovic knew he had to play at his best against Federer,

who defeated him earlier in the week at the group stages.

The champion seems to be pretty proud of the win.

I'm just trying to enjoy every moment,

you know, on the court, and cherish every moment that I

You know, when you are a kid growing up, dreaming to play

tennis, it's your dream to be into a tournament like this and to fight

for the biggest trophies in the sport.

So thank you all very much for making this day special.

Some wildlife news now and a northern white rhino, one of only

four believed to be left in the world, has died at a zoo in

Nola, a 41-year-old female had been living at San Diego Zoo Safari Park

She had to be put down after becoming ill.

Just three remaining northern white rhinos live at a highly

Rhinos are under threat in the wild because people hunt them

Next to the dramatic rescue of Mufasa the lion believed to be the

last wild animal in a South American circus.

It's thought Mufasa had been captured from the wild as a cub and

the circus kept him chained to the back of a truck his whole life.

After being rescued and brought back to health the 22-year-old big

cat was taken on a three day journey, by road and boat, to a

special reserve in the Amazon rainforest where he can now live the

Thousands of starling birds flying together to create mesmerising

It's thought it could be a form of protection from predators, or a way

And now it's been discovered flocks continue swarming

A new study has found they can fly around for more than an hour, with

researchers also surprised at just how many mumurations there are.

It's murmaration season right now so head online to the Newsround website

and find out more about how you can spot them.

Now to a high-tech solar powered plant that

It's in Morroco in North Africa and uses melting salt to create energy.

Wasassat, an ancient city in East Morocco is

Row upon row of mirrors capturing the power of the desert sun.

Once complete, it will be able to provide energy to a million people.

During daylight hours, these mirrors track the sun through the sky.

It is known as concentrated solar power.

Each mirror directs the sun's rays that hit the tube

Outside the tube is oil which is boiled to 400 Celsius,

then transported and used here to make steam and produce electricity.

But in order to generate power after dark,

it uses the sun's energy to melt salt in this huge cylinder which has

This thing you see here is a tank where we store salt just like the

During the day, we heat this up, in order to keep the heat we will

use to produce electricity, and this is quite a big innovation.

We are able to store up to three hours of energy.

It's hoped that this sort of technology is the future of

renewable energy and poorer nations want help from rich countries to

develop technology like this to help fuel the future, day and night.

I'm pretty sure singing your national anthem in front

of thousands is something no one would forget.

Well, this 7-year-old boy from Australia stole the show

Ethan here stepped up to sing the national anthem before

And then still managed to finish the song after a -- his pick-ups

interrupted the song. Ethan still managed to finish the

song and got a massive round of