What is believed to be the world’s oldest Humboldt penguin has celebrated her 32nd birthday with a watermelon and fish cake.

Rosie the penguin was joined in the celebration by her children Twinnie, Webster and Flip Flop, and her first grandchild Pickle, at Sewerby Zoo in East Yorkshire.

Zoo staff believe that she is the oldest Humboldt in the world, and sang her Happy Birthday to mark the occasion.

Head zookeeper John Pickering told the PA news agency it is “remarkable” that Rosie has made it to the age of 32.

Humboldt penguins usually live to between 15 and 20 years old in the wild, but live longer in captivity because “they haven’t got things like leopard seals and other predators chasing them”, Mr Pickering told PA.

“(Rosie) spends a lot of time sleeping now because of her age…we hand feed her so she does not have to compete with the others in the pool.

“We’ve decorated the enclosure, we’ve put some bunting up, and we’ve also made her a cake,” Mr Pickering added.

Rosie has lived at the Sewerby Zoo in East Yorkshire since 1990 (East Riding of Yorkshire Council/PA)

Humboldt penguins are listed as a vulnerable species according to the International Union for Conservation of Nature, and their population is thought to be declining in number – with fewer than 24,000 adults remaining in the wild.

The species lives in northern Chile and Peru, and is capable of swimming underwater at up to 30 miles per hour.