There's double trouble afoot at Folly Farm in the latest baby boom for the zoo.

A pair of critically-endangered red-ruffed lemurs have been born at the park - twin boys for parents Pogel and Louis.

The delightful duo, born earlier this month, have been named Sirius and Remus and mark a significant step for the zoo in helping to expand the community of red-ruffed lemurs in captivity.

The species are natives of the island of Madagascar and there are currently only 591 of them captive in the world. They are considered to be type of primate at the highest level of extinction.

Said zoo manager Tim Morphew: "Due to their dwindling numbers in the wild, it is important that we play our part in helping to maintain a strong population of red-ruffed lemurs in captivity.

"Our red-ruffed lemurs have not produced any offspring for a few years now, so we are delighted to welcome Sirius and Remus to our growing lemur family at Folly Farm."