One Zoo Three Family-owned centre can be 'beacon of hope'

Outside the enclosure, eager visitors jostle for a glimpse of rare Asiatic lions Sahee and Sonika, Hertfordshire zoo's newest residents. The beasts yawn imperiously in the sun, every twitch of their tails sparking an excited murmur.

- Alexandra Topping

But when Aaron, Tyler and Cam Whitnall are spotted, the animals are instantly forgotten. The stars of the BBC children's programme One Zoo Three are tenderly, but relentlessly, mobbed. "We got up at 5am to drive here," explains one delighted, if bleary-eyed dad. "My daughter just loves you."

She is not the only one. The three brothers have become stars of children's TV since the first series about their lives on their family zoo aired in 2000. But four decades after their grandparents bought "the worst zoo in the UK", they have their sights on becoming a world-leading conservation organisation.

"We want to be a beacon of hope here," says Tyler, the middle brother, recovering from the adoration with a cup of tea in Zoo HQ. "One day we want to be known as the best zoo in the UK, up there with Chester, and a leader in terms of education, wildlife conservation, sustainability. We literally want to be at the top."

It's a big ambition. Hertfordshire zoo is a small zoo, even by UK standards, with about 1,000 animals across 16 acres - by comparison, Chester has at least 37,000 animals over its 128-acre site. But as the home of One Zoo Three its footprint in the online world and children's imaginations is outsized - and its presence on the global stage is growing.