Britain's Prince Harry appealed on Monday in a national park in Malawi for increased global efforts to protect the environment against "greed, apathy and selfishness".
Harry, whose tour of southern Africa has taken him to four countries, observed a simulated anti-poaching operation by Malawian rangers and British soldiers aimed at protecting endangered species such as elephants and rhinos.
"Conservation used to be a specialist area, driven by science. But now it is fundamental to our survival and we must overcome greed, apathy and selfishness if we are to make real progress," Harry told Britain's Daily Telegraph newspaper.
"This may well sound hippy to some, but we cannot afford to have a 'them or us' mentality. Humans and animals and their habitats fundamentally need to co-exist or within the next 10 years our problems across the globe will become even more unmanageable."
Harry, the grandson of Queen Elizabeth, also guest-edited National Geographic magazine's Instagram account on Monday to encourage people worldwide to appreciate the value of trees, Buckingham Palace said.
In a campaign entitled 'Looking Up', the Duke of Sussex posted pictures taken by National Geographic's photographers - among them images from the Liwonde National Park that he was visiting - to raise awareness of trees' vital role in the Earth's eco-system.
Harry has launched a number of projects under the "Queen's Commonwealth Canopy" initiative, which has, among other things, involved planting of millions of trees in dozens of Commonwealth countries to help combat climate change.
In a speech to welcome Liwonde National Park and Mangochi Forest to the initiative, Harry praised cooperation between Malawi's rangers and British soldiers.
"From tackling poachers on the ground to sentencing in the courts, this work is successfully rooting out wildlife criminals at every stage, and removing the incentive by prioritising the punishment," he said.
Mike Polera, a Malawian park instructor, said he had learned about tracking poachers in dense forest.
"The British soldiers are experienced in jungle tracking while we are good at bushcraft, and we are also exchanging skills," Polera said.
Harry, sixth in line to the throne, paid tribute at a memorial site for a British soldier, Guardsman Mathew Talbot, who was killed in May by an elephant while taking part in counter-poaching operations.
Harry has been travelling to southern Africa for two decades for holidays and conservation work.
After visiting South Africa last week with his wife Meghan and their four-month-old son Archie, he left them there and travelled alone to Botswana, Angola and Malawi.
Meghan on Monday visited Johannesburg's Victoria Yards, a redeveloped complex of former industrial buildings that now houses markets and artists' studios.
A post on the coule's Instagram account showed her hugging three young girls, and said she had been struck by the work of a local denim designer. It also highlighted a number of local organisations that support marginalised youth and women.
On Tuesday, Harry will visit a health centre, pharmacy and youth reproductive health programme in Malawi. He will then rejoin Meghan and Archie in South Africa for a township visit on Wednesday near Johannesburg.
They will also meet Graca Machel, widow of South African anti-apartheid icon Nelson Mandela, and President Cyril Ramaphosa before returning to London.