Chester Zoo

Vets perform sight-saving surgery on penguin at Chester Zoo

Posted: 25th April, 2021

A team of eye specialists have carried out sight-saving surgery on a penguin at Chester Zoo.

Four-year-old Munch, a Humboldt penguin at Chester Zoo, was discovered to be experiencing blindness in both of his eyes from cataracts, a disorder which creates cloudy patches on the lens which get bigger overtime.


Bird conservationists noticed the issue when Munch was having difficulty catching fish during feeding times and started bumping into other members of the zoo’s colony of Humboldt penguins - a species listed by the International Union for the Conservation of Nature (IUCN) as vulnerable to extinction.

Following an assessment by the zoo’s team of on-site vets, it was decided that only specialist treatment could save Munch’s sight, and so animal optical care experts at Eye Vet were called in to help perform the zoo’s first ever penguin cataracts operation.

Now, just a few weeks after his surgery, experts at the zoo have reported that Munch is back with the rest of the colony and nearing a full recovery.

Sophie Bissaker, Parrots and Penguin Keeper at Chester Zoo, said:

“We spotted that Munch was swimming slower than normal and was struggling to dive for the fish at feeding times – and if a penguin can’t catch a fish then you know something is amiss. That’s when we called in the zoo’s vets.

“After a thorough examination, the team discovered that Munch had cloudy patches on the lenses in each of his eyes – leaving him with very little sight in his left eye and none at all in his right. This meant that only specialist treatment could save his vision.”

Munch was quickly transported by the zoo’s dedicated bird keepers to specialist veterinary ophthalmologists at Eye Vet in Sutton Weaver, Cheshire, where he underwent a 2-hour procedure to carefully remove cataracts in his eyes.

Iona Mathieson, Veterinary Ophthalmologist at Eye Vet and expert in animal optical care, carried out the delicate surgery.

She said:

“I’ve been in the veterinary field for almost 24 years and Munch is the very first penguin I’ve operated on – they’re not regular clients that’s for sure. Unfortunately, because his quality of life was impacted by the diminished sight, surgery was the only option we had available to us.

“We had seen the news about how the Covid-19 pandemic had massively impacted Chester Zoo, and this sort of surgery can certainly be costly. Eye Vet was therefore more than happy to donate both equipment and time to help out. We also approached several companies that manufacture specific items that we needed for the surgery to see if they’d kindly donate it to us and, wonderfully, they all agreed. We’re really happy to report that the surgery was successful and Munch is now well on the way to making a full recovery.

“Like many of the staff at the zoo, our team has worked throughout the national lockdowns, so we’re all feeling mentally and physically exhausted, but taking care of Munch was just the morale boost that we all needed. It’s an amazing feeling knowing that we’ve helped save him, he’s the first thing that made me smile in a long time and caring for him was definitely the best part of my year. We can’t wait to visit him and the penguin colony now that the zoo has reopened.”

Following his procedure, Munch spent time recovering in a shallower nursery pool while keepers monitored his post-surgery progress. During this time, he was joined by his life partner and best friend, Wurly, who kept him company throughout his recovery.

Sophie added:

“It was important for Munch to have time away from the rest of the group for a couple of weeks following his surgery while we regularly checked up on him. But, penguins live in tight-knit colonies and like to be with other birds, and so we decided to provide Munch with some company with his life partner Wurly. Munch really dotes on Wurly and wherever she goes, he follows, so I’m sure she provided some great comfort to him. The pair have always been inseparable and even had their first chick, Leek, in 2019 and are even incubating eggs once again!

“It’s been an emotional rollercoaster for everyone involved, and although Munch is still receiving daily eye drops to help him heal, he’s already swimming through the water faster, feeding with the group again and waddling around with ease. He’s a confident, happy little guy again!

“We are incredibly lucky to have our onsite vet team who dedicate their time and expertise solely to the 20,000 animals in our care. That, alongside the wonderful generosity from the team at Eye Vet, is the reason Munch’s recovery has been so successful.”

Of the world’s 18 penguin species, the Humboldt penguin is becoming increasingly rare and is considered by experts to be among the most at risk.

Found on the rocky coastal shores of Peru and Chile, the penguins face a number of threats such as climate change, over-fishing of their natural food sources and rising acidity and temperature levels in the oceans – all causing the penguins to search further from their nests for fish and increasing their vulnerability.

Humboldt penguin facts

  • Scientific name: Spheniscus humboldti
  • This South American penguin is named after the chilly Humboldt current, along which the penguins commonly swim
  • Of the world’s 18 penguin species, Humboldts are among the most at risk, with the species classed as vulnerable to extinction by the International Union for the Conservation of Nature (IUCN)
  • In the wild, Humboldt penguins are vulnerable to disturbances in their food chain caused by strong El Nino currents
  • Humboldt penguins are social animals, living in relatively large colonies of closely spaced burrows
  • Humboldt penguins ‘fly’ through the water at speeds of up to 25mph
  • They enjoy a diet of small fish (anchovies, herring, smelt) and crustaceans



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