During the programme, he was shown images of rhinos with their horns removed by poachers and appeared close to tears.
"Seeing a badly injured animal such as a rhino, seeing its horn, it's come, for me, to symbolise human greed," said the Prince.
"I feel a real protective instinct, also now probably more so now that I am a father, which is why I'm getting quite emotional about it."
William said he hopes he will pass on his love for endangered animals on to his young son, by "whispering sweet nothings in his ear" about them, and filling his nursery with toy elephants and rhinos. He also hinted that he would one day take Prince George to Africa.
"The last few weeks, for me, have been a very different emotional experience, something I never thought I would feel myself.
"It's only been a short period, but a lot of things affect me differently now.
"It's a daunting task when you realise that you want to pass on things to your son, and suddenly you start to realise 'wow', there's stuff you want to safeguard for the future.
"I've always believed it, but to actually really feel it too, it's coming through quite powerfully now."
- PAA
