Staff at RSPCA's Mallydams Wood Wildlife Centre have begun playing pieces of the dawn chorus twice a day to fledglings in their care.

The scheme was put into action after scientific research discovered birds reared in captivity may benefit from listening to bird song from the same species before being released back into the wild.

The CDs contain a variety of calls so the birds in care can fully understand the language of their species and help with their survival in the wild.

Richard Thompson, wildlife officer at Mallydams, said teaching birds to sing properly was important for communication, security and mating.

In particular, males without a proper singing voice are not able to attract a female, he explained.

"We felt this scheme was important to develop the mental abilities of the birds," he said.

"The birds are in large aviaries to develop their physical abilities.

"Together the result is hopefully to allow them to attract partners and be capable of living in the wild."

The project is underway in four RSPCA centres, including the Mallydams rehabilitation centre, and further research into benefits of the scheme will be carried out later this year.

The RSPCA receives about 4,500 fledglings a year across the four centres.