The BBC have been forced to add a clarification to the beginning of an episode of David Attenborough's most recent show Secret Garden after viewers complained about a glaring error in the narration. The five-part series, which is currently available to view on the BBC iPlayer, launched on Easter Sunday, April 5, and chronicles the drama occurring in the concealed wild realm of remarkable gardens. Throughout the series it featured intense scenes of otters, kingfishers, and foxes in gardens across the UK.

While many viewers praised the show online calling it "amazing" others went directly to the BBC with an issue. In the second episode it transpired Attenborough, who recently celebrated his 100th birthday, made an erroneous statement in his voice over. The BBC issued a statement on the Corrections and Clarifications page on their website writing: "During a sequence about blue tits in episode two of Secret Garden, our narration incorrectly claims that 'To successfully fledge, each chick will require 20,000 caterpillars,'" it began.

"This should have said '2,000' as each chick needs 100 caterpillars a day and they take approximately 20 days to fledge as per the latest guidance from the British Trust for Ornithology.

"It is therefore all ten chicks who require 20,000, not one. We have added a clarification strap at the start of the episode and apologise for the error in the narration," they concluded.

It is unknown how many people raised the issue but to merit an official mention on the website at least 100 people need to have contacted the broadcaster about an issue.

The offending episode was shot in Bristol in a tiny city garden measuring just 10 metres across which played host to a plethora of wildlife.

It showed the Blue Tit family struggling with city life as they had to compete with goldfinches and pigeons for a place at the bird feeder.

It also featured a fox in search of both food and a mate, hedgehog emerging from hibernation and frogs and dragonflies making the pond in the garden their home. The show also looked at the assortment of insects and spiders which colonised the sun-warmed walls.

Prior to the show launch the producer Bill Markham explained why they chose nation treasure Attenborough as narrator. "At a time when wildlife gardening is becoming increasingly important for supporting struggling species, his voice carries particular weight.

"If Secret Garden succeeds in encouraging people to rethink what their gardens can be, it will be in no small part due to his influence and enduring credibility. We are, after all, a nation that loves animals, gardens - and Sir David Attenborough. This series brings all three together. It's a powerful combination," he said.