Red kites are scavengers which eat already dead animals
The illegal poisoning of a rare red kite in the Yorkshire Dales is being investigated by police.
The bird of prey was found dead in the Greenhow area near Pateley Bridge in Nidderdale in January.
It had eaten bait laced with the pesticide alphachloralose, which is often used illegally as a pest control.
A national park spokesman said: "Given there are so few here, the loss of one bird will have a very significant impact on the local population."
He said the species was only just starting to breed in the Yorkshire Dales again after an absence of several hundred years.
'Cruel and unnecessary'
"We hope the police will be able to track down those responsible and we would ask those visiting the National Park to report any suspicious incidents they see to the police."
North Yorkshire Police are working with the RSPB, Natural England and the Yorkshire Dales National Park Authority, to highlight the importance of protecting rare species.
James Leonard, RSPB investigations officer, said: "As well as being cruel, unnecessary and illegal, it is also selfish because it denies people the sight of these magnificent birds.
"Red kites were lost from England once before because of this kind of persecution and only brought back after a major effort."
Police warned that the pesticide not only put red kites at risk, but was also a danger to people visiting the Dales and local residents' pets.