A rare monkey at Chester Zoo has had a baby just months after surgeons saved her foot from amputation.
Masaya, a 15-year-old roloway monkey, underwent surgery last summer after developing a golf-ball-sized mass on her foot. Zoo veterinarians worked with surgeons from the University of Liverpool’s Small Animal Teaching Hospital to remove the mass and preserve as much of the foot as possible.
The medical team said it could find no previous examples of the same procedure being performed on a roloway monkey. The operation was successful, and Masaya kept all but one of her toes.
Masaya has now given birth to a daughter named Lagertha, an important addition to a species believed to number fewer than 2,000 in the wild.
Rachel Burrow, a veterinarian and lecturer at the University of Liverpool, helped with both Masaya’s CT scan and the operation.
“This was the last chance to save Masaya’s foot before amputation. Working with primates is completely different from my usual patients, who are typically cats and dogs, and it was a real privilege to care for such a rare animal. It’s great to see the surgery was a success – she’s comfortable, active, and using the limb well,” she said.
Chester Zoo primate keeper Zoe Edwards said Masaya was coping well as a mother.
“Masaya is a very experienced mum and she’s parenting magnificently. Lagertha is only a few weeks old and is very dinky, but already curious about the roloway monkey habitat and inquisitive about us,” she said.
“The fact Masaya’s foot has healed so well is a huge relief. If she’d had an amputation, we’d have been left with real questions about whether she could hold her offspring or continue with her normal behaviors.”
Lagertha is Masaya’s third daughter. Edwards said the birth mattered for the species because Chester Zoo is one of only two places in the UK with roloway monkeys, and there are only a few breeding females in zoos across Europe.
“Chester Zoo is one of only two places in the UK that roloway monkeys can be found, and Masaya is very important – not just to her family, but to her whole species. There are only a few breeding females in zoos in Europe,” she said.
According to the International Union for Conservation of Nature, fewer than 2,000 roloway monkeys remain in the wild. Their natural range includes Ghana and the Ivory Coast, where they are threatened by habitat destruction and poaching.
Masaya is part of the European Endangered Species Programme, a coordinated breeding effort designed to help safeguard the species from extinction.
Her foot problems began before the operation and had continued since she arrived at Chester Zoo in 2023. Veterinarians carried out X-rays, ultrasounds and biopsies, but the cause remained difficult to determine. They eventually suspected a persistent abscess, possibly caused by an old injury from a thorn.
By 2025, the swelling had worsened, and staff took Masaya to Liverpool for a CT scan.
Charlotte Bentley, veterinary officer at the zoo’s animal health center, said: “It’s not every day you take a monkey to vet school. We had to bring everything she might need, from anesthesia equipment to medications and blankets.
“Following the scan, we decided an operation was the way forward. She’s been an absolute trooper all the way through, and I’m just glad we were able to do something for her.”
Masaya has since recovered well, and Lagertha is now living with her and four other monkeys at Chester Zoo.
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