The Duke of Cambridge has spoken movingly about how the birth of his son has increased the depth of his feelings towards endangered animals.
William was left close to tears after being shown footage of a rhino attacked by poachers and left bleeding to death during filming for a documentary.
The royal was interviewed in July soon after the birth of his son Prince George and in the programme, to be screened by ITV and CNN on Sunday and Monday respectively, talks about his passion for wildlife and how fatherhood has changed him.
The Duke spoke to the Radio Times about his connections to an animal charity
But it's not just nature's impressive big animals that have an effect on the royal, he also revealed how he is "not so good" with spiders and snakes.
Documentary film maker Jane Treays, writing in the latest edition of the Radio Times, described the build up to the interview for the ITV programme and the events on the day.
During the informal chat filmed at Kensington Palace William, who has a strong interest in animal conservation, told her: "The wildlife is incredibly vulnerable and I feel a real protective instinct, more so now that I am a father, which is why I get emotional about it... you want to stand up for what is very vulnerable and needs protecting.
"Elephants, rhinos and many other animals that are persecuted don't have a voice."
Ms Treays wrote that William became emotional when shown footage of the rhino "watching pictures of a butchered rhino bleeding to death. Tears well in his eyes and he confesses to everything being changed by the birth of his son."
The Duke says in the documentary: "It's just so powerful. You'd think something that big and that's been around so long, would have worked out a way to avoid being caught and persecuted, but they really don't. I do feel anger, but I also feel really great hope that we will overcome this as a human race."
William's family, from his grandfather the Duke of Edinburgh to his mother Diana, Princess of Wales, have inspired him to champion causes he believes in.
The Duke said: "The legacy is quite a daunting one, following on from my grandfather and father. It just sort of happened... My mother would come back with all these stories, full of excitement and passion for what she had been doing and I used to sit there, quite a surprised little boy, taking it all in - and the infectious enthusiasm and energy she had rubbed off on me."
William's interest in Africa's natural world is reflected in his royal patronage of the UK-based African wildlife conservation charity Tusk Trust.
The Cambridges will attend the organisation's inaugural awards ceremony in central London on Thursday night.
Two awards will be presented, a lifetime achievement honour named after the duke and another recognising an up-and-coming conservationist, with the ceremony filmed for the documentary.
In the programme William stressed his love of the continent: "Africa, emotionally and mentally, has affected me. It's magical. Every time I go back it brings out new things. This is a lifelong commitment and I'll always be involved ... no matter what."
Africa is also a place where he can be himself, he told Ms Treays: "I love the fact you can go into any village in Kenya or the east coast of Africa and just walk in and have a chat with someone and they have absolutely no idea who you are. Usually my Swahili stops after about two sentences but we muddle through in English."
He revealed that he uses the continent's wildlife to help stay relaxed: "I've got hundreds of animals on my iPhone, noises and sounds of the bush, so if I'm having a stressful day, I'll put a buffalo, a cricket or a newt on and it takes you back instantly to the bush. And it does completely settle me down."
Speaking about endangered animals the duke said: "It's horrifying. It's hard to put into words, the depth of sadness that I would feel if they became extinct."
He added: "I want the (Tusk Trust) awards to be credible in the conservation world and for those who receive them to realise how fantastic their work has been. They are leading the way. Now is the time to galvanise and energise all the people who want to help."
Tusk Trust establishes and promotes community-driven conservation programmes in Africa and William told Ms Treays he realised it had to work with local people whose livelihood could be threatened by wild animals.
He said: "We have to remember how desperately poor these guys are ... this is all they have known, living in these communities with their cattle and goats, and they will protect them to their last breath. Their water and grazing is in very short supply. Conservation has to have these communities' blessing."
But he stressed education was a major weapon in fighting illegal poaching: "The way they are doing things is getting more and more sophisticated. As soon as you find a way of dealing with it, they find another.
"Education is such a huge, important issue, to educate everyone involved in the illegal markets about the damage that can be done and the implications of what they are doing."
Asked by Ms Treays about the legacy for Prince George he laughed: "At the moment, the only legacy I want to pass on to him is to sleep more and maybe not to have to change his nappy quite so many times, but as he gets older I'm sure he'll pick up the bug of conservation."