The hen harrier has been tracked by the RSPB via a lightweight satellite tag since it hatched in the Peak District during the summer.
On the morning of Friday 26 October, the hen harrier flew into the North York Moors National Park. The bird's last registered position was recorded just north of Lowna Bridge, near Hutton-le-Hole.at 9.55am that same day.
The tracking tag has not been located and no body has been found, so the police are now investigating alongside the RSPB.
North Yorkshire Police are asking anyone with information that could assist their investigation to come forward. The Alliance recommends that anyone wishing to do so contacts the police directly by dialling 101 or, if you wish to remain anonymous, by calling Crimestoppers on 0800 555 111. Further information can be found on our How to Report a Wildlife Crime page.