Twycross Zoo is waiving the entrance fee to visitors with red hair on Friday, August 19, to celebrate World Orangutan Day.
The event will raise awareness of the dangers the ape faces in the wild, where they are viewed as pests by palm oil farmers and are on the verge of extinction.
The animals are either killed by farmers or left to die in forest fires that are used to make way for plantations.
Twycross has four Bornean orangutans, a male called Batu, along with three females, Kibriah, Maliku and Molly, who were all born at the zoo.
The zoo is a partner with the United Nations Great Ape Survival Partnership.
Entrance staff will check hair colour against a colour scale to check whether visitors with ‘borderline’ red hair can get in for free or not.
A spokesman said: "We will be letting anyone with red hair in for free – male, female, adult, child, strawberry blonde, auburn, fiery red, natural or dyed – it does not matter.
"However, if you come in wearing a wig you will have to pay the entrance fee."
