After initialling saying it was investigating the allegations, Cadw has now admitted using contractors for the controversial bird control.
A Cadw spokesperson said: “We have a duty of care to visitors to ensure they are kept safe at our sites. Birds and their faeces may carry diseases which are harmful to humans.
“The control of certain birds, including feral pigeons is permitted under a Wildlife and Countryside Act general licence issued by Natural Resources Wales. A general licence is issued annually by NRW for the purpose of protecting public health and public safety.
“There are a number of ways to control feral pigeons, and when no satisfactory alternative is effective or practicable, as a last resort, shooting by trained individuals is the most humane. Any control activity is limited to within the castle walls.
“Cadw and its contractor act in accordance with the conditions listed on the Wildlife and Countryside Act General Licence 002/2019 to kill or take certain wild birds for the purpose of preserving public health and public safety.”
Carol Gravenor, who runs Caerphilly Bird Rescue alongside her husband Ray Gravenor, said that around 50 or 60 birds were shot all together, including seven of their own.
Mrs Gravenor said: “There’s no need for these things to happen. I’m absolutely furious. I feel ill.
“One of the birds that was killed was a pigeon which we had looked after for a month and only released two days ago.”
Caerphilly Assembly Member Hefin David said he was disappointed at the lack of information provided by Cadw initially and will continue to pursue them for answers.
Plaid Cymru councillor Lindsay Whittle, who represents Penyrheol, described the policy as “barbaric” and said any tourists witnessing a culling wouldn’t inspire them to return to the town.
Labour’s Morgan Jones ward councillor Jamie Pritchard added: “Why the massive long wait to finally come clean to admitting they were indeed responsible for the mass shooting of birds? Cadw say they’re complying with legislation, but if this is true, then many people will conclude it to be licensed murder.
“A large number of residents have said how horrified they are with Tuesday’s events and a full review on the goings on should take place.”
The type of general licence used by Cadw contractors is a general one issued by Natural Resources Wales.
In England, this type of licence is now no longer used after a legal challenge from campaign group Wild Justice, which was founded by TV presenter and conservationist Chris Packham.
An earlier version of this article incorrectly implied that Chris Packham was behind the legal challenge to end the general licence in England, rather than Wild Justice.