Prince Harry’s rhino conservation charity is appealing for help with a new year challenge, naming a rhino.

Fans of the No 1 Ladies’ Detective Agency novels by Alexander McCall Smith are being asked to pick one of three animals which will be given the name of the author’s heroine Precious Ramotswe.

The books are set in Botswana, a country Harry calls his second home and where he invited fiancee Meghan Markle to camp out “under the stars” in the early days of their relationship.

A Precious Ramotswe candidate who could win the public vote to name a white rhino (Rhino Conservation Botswana)A Precious Ramotswe candidate which could win the public vote to name a white rhino (Rhino Conservation Botswana)

The prince is UK patron of Rhino Conservation Botswana (RCB) which has selected three female rhinos for the naming competition, that match McCall Smith’s description of his lead character, “traditionally built and beautiful”.

Sophie Stafford, a spokeswoman for RCB, said: “These ancient and precious animals are being poached to extinction in many parts of Africa, but are thriving in Botswana’s Okavango Delta thanks to robust wildlife protection laws and RCB’s work to keep them safe and healthy.”

She added: “The idea behind the vote is to celebrate the anniversary of Mma Precious Ramotswe’s fictional debut while also raising awareness of the invaluable work happening in her homeland to protect wild rhinos.”

The conservation organisation helps protect Africa’s two surviving native rhino species, the black and the white rhino, rescuing them from poaching hotspots across southern Africa and relocating them to northern Botswana.

Black rhino are classed as critically endangered with fewer than 5,000 left in the wild, while white rhino are near threatened with an estimated population of around 20,000.

Harry joined an RCB operation to help protect black rhinos in Botswana in September 2016, clearing thorn bushes from around sedated rhinos so tracking equipment could be fitted, he also monitored the animals’ breathing and heart rate and helped to keep them cool with water.

The 20th anniversary of the publication of McCall Smith’s first book in his detective series is celebrated this year.

A spokesman for the author said: “We are all thrilled that Precious Ramotswe might be able to help the Rhino Conservation Botswana charity in some small way. She would be delighted.”

Voting to choose one of three white rhinos to be named will remain open until June 30.