Steve Irwin's son joins Prince William in South Africa

Prince William has joined Australian wildlife conservationist Robert Irwin, the son of the late Steve Irwin, for a mountain ramble during the royal's tour of South Africa.

The pair walked up Signal Hill, famed for its sweeping views of Cape Town and Table Mountain, and spoke to rangers and volunteer conservationists there about the area's biodiversity.

The area is part of the Cape Flora Region, a Unesco world heritage site since 2004 due to its rich plant biodiversity.

The Prince of Wales is in Cape Town on a four-day climate-focused tour, culminating in his presentation of the Earthshot Prize on Wednesday night.

The prize, started by Prince William, supports sustainable, eco-friendly projects from around the world, with five winners each receiving £1m.

In blustery but sunny weather on Tuesday, the Prince, dressed in sustainable clothing, walked through the park and viewed the panoramic views down over Cape Town from one of the world’s most recognisable tourist attractions.

The Prince was guided through the National Park by park rangers, firefighters, mountain rescue volunteers, biodiversity experts and youth volunteers led by Robert Irwin, the son of Australian conservationist and TV presenter, Steve Irwin, who was killed by a stingray in the Great Barrier Reef in 2006.

In a video posted to his social media accounts, Irwin asked the Prince about his favourite African animal.

Prince William, who said he had been quizzed on the issue by his children a number of times previously, put his vote to the cheetah.

Irwin backed the "unsung hero" - the chameleon.

Irwin has long been a keen wildlife photographer and became an Earthshot ambassador in September.

"For the first time we have an environmental movement on a scale we’ve never seen before," Irwin said of the prize.

"It’s really putting money where it's needed most, putting support and awareness where it’s needed most but it's also leading with a sense of positivity - it's this beacon, this light we can all strive towards," he added.

The prince later met with South Africa's president Cyril Ramaphosa and the UK's Foreign Secretary David Lammy.

Lammy is visiting Nigeria and South Africa in a tour focused on economic growth.

The Prince thanked the President for his support of the Earthshot Prize and told the President how he had enjoyed visiting Ocean View Township on Monday, where he joined in with some rugby training.

He told President Ramaphosa it highlighted the power of sport to unite communities.

Prince William had dusted off his self-professed “rusty” rugby skills with some legends of the sport, including former Springboks Joel Stransky and Percy Montgomery.

The prince is later expected to deliver a speech on nature, the environment and his support for wildlife rangers at the start of a two-day summit for United for Wildlife, his umbrella organisation combating the illegal trafficking of animals.