"What (the committee) has not done is made any allowance for the amount of money that comes back to the public purse once the land on the park has been sold, " Robertson told the BBC.
When due allowance was made for habitat differences, they found that species which relied on a class of chemicals called carotenoids to tint their feathers fared worse when there was more radioactivity around.
He called for all MPs claims to be published on the internet once they are made and said the communications allowance for sitting MPs was a "gigantic waste of money" and should be abolished.