A nesting male Hen Harrier has disappeared from the North Pennines, leaving his five eggs.
The bird was last seen at the upland site of the RSPB’s Geltsdale reserve on Saturday 23 May.
He set off hunting at around 7.15am and was last observed by RSPB nest protection staff at around 1pm.
As the male didn't return to provide the female with food, she was forced to abandon her clutch of five eggs. This resulted in the failure of the nest, according to the RSPB.
Hen harriers are England’s most threatened breeding bird of prey with only four successful nests in the whole country last year.
Police are also calling for anyone with information to come forward.