William And Kate At Big Cats Film Premiere

The Duke and Duchess of Cambridge have walked the red carpet at the UK premiere of African Cats, a film about Kenya's threatened wildlife.

Photographers shouted for the attention of the royal couple, who celebrate their first wedding anniversary on Sunday, as they arrived at BFI Southbank in London.

The documentary, which is raising funds for the Duke's UK-based charity Tusk Trust , is about a pride of lions and a family of cheetahs battling for survival on Kenya's plains.

Mark Knopfler, former member of the group Dire Straits, was among the guests, along with filmmaker Guy Ritchie and Dragons' Den judge Deborah Meaden, a patron of Tusk Trust.

Hollywood star Patrick Stewart narrates the true-life story of cheetah Sita bringing up her five cubs in the Masai Mara game reserve and of Mara, a six-month-old lion cub being raised by her mother Layla.

Charlie Mayhew, co-founder of Tusk Trust, said of the Duke: "He's passionate about Africa... he's very concerned about the current crisis.

"We are now seeing daily reports of elephants being poached across the continent and in South Africa the country has lost 170 rhinos already this year."

He added that the number of cheetahs on the continent stands at up to 12,000, while estimates suggest only 25,000 lions are left in Africa.

After the screening William gave an impassioned speech, calling for the world to try to halt the threat to lions and cheetahs.

He started by joking about the emotional rollercoaster the audience had been through watching the cubs grow up.

William said: "Wow - that was amazing. I'm emotionally exhausted.

"There's more drama in that than EastEnders. What that told me was - who needs men?"