Concerns have been raised after the possible disturbance of a peregrine falcon's nest in the Forest of Dean.
Police have released an image of a man they want to speak to, who was seen climbing over a cliff near the nest on 24 May:
Disturbing the nest risks the birds failing to breed this year.
Peregrines are a protected species, and it's a criminal offence to kill or injure one.
It is also an offence to "intentionally or recklessly disturb the birds" close to their nest during the breeding season.
Officers are working with Gloucestershire Wildlife Trust and the Gloucestershire Raptor Monitoring Group to identify the man and establish his intentions.
There are only a small number of nest sites in the county.