A critically endangered piglet the size of a grapefruit has been born at Chester Zoo.

Babirusas, one of the oldest wild pig species still alive today, are being wiped out in the wild by African swine fever.

Chester Zoo's newest addition, Little Rana, is a babirusa - sometimes called the "pig-deer" - a species found on just four Indonesian islands.

Babirusas were until recently classified as vulnerable to extinction by the International Union for Conservation of Nature (IUCN), but are shortly due to be uplisted to critically endangered.

Wild populations have declined rapidly since African swine fever reached the islands around five years ago, with conservationists warning the disease could push the species towards extinction.

Rana was the size of a "grapefruit with legs" when she was born. She's the fifth piglet born to mother Matano, who was herself born at Chester Zoo 11 years ago and now has descendants living in zoos across Europe.

Hannah Owens, assistant team manager at Chester Zoo, said the birth was the zoo's first babirusa birth for several years.

"Rana is a very special little lady," she said. "When she was born, she was tiny - about the size of a grapefruit, with legs. She's grown a lot and is doing really well.

"While babirusas are doing well in our care, I'm worried because they are really struggling in the wild. The numbers are radically reducing, and it would be horrendous if they disappeared, because they are amazing, charismatic animals. Piglets like Rana are a lifeline for the species."

Babirusa pregnancies are unusually predictable, with almost every birth at Chester Zoo occurring after exactly 161 days of gestation.

Keepers began counting down after Matano was seen with male Bamm Bamm earlier this year. She was later given a quiet, private space and extra bedding ahead of the birth.

Unlike most pigs, babirusas typically have only one or two piglets at a time rather than large litters, meaning populations can take longer to recover following a decline.

New mothers can also be particularly sensitive to disturbance. Keepers therefore monitored Matano and Rana remotely using a baby monitor until they were ready to be seen by visitors.

Chester Zoo conservationists are working with partners to protect wild babirusa populations through the Action Indonesia Global Species Management Plans.

The programme supports camera-trapping projects on Sulawesi to monitor babirusas, helps partners locate and protect surviving populations and shares conservation breeding expertise. This work has helped Indonesian colleagues breed at least 17 babirusas towards national cooperative breeding targets.

Amy Humphreys, a conservationist at Chester Zoo and member of the Action Indonesia programme, is helping to develop a new Indonesian government plan to protect babirusas in the wild.

She also witnessed the decline in babirusa numbers reflected in a recent camera-trap study carried out in Sulawesi with support from Chester Zoo.

The study recorded just two instances of babirusas being photographed across 2023 and 2024.

Amy said: "We are in a race against time to understand what's happening to the population.

"Babirusas are important to island ecosystems as they drop seeds as they forage, helping forest regeneration, and they are a key indicator species for overall ecosystem health, but their situation is bleak.

"We risk losing a truly unique species, one that's an important part of Indonesia's cultural and natural heritage and one of the oldest pig species still living.

"Because of all this, Rana's arrival is worth celebrating. Her birth is a chance to shine a light on babirusas and show people why they deserve protection."