Two swans died after being shot in Leeds, police have said.
CCTV images of a man seen in the area with a rifle at the time of the incident have been released, and police are appealing for help to identify him.
The male and female swans were shot on marshland next to Knowsthorpe water treatment works, Pontefract Lane, at about 21:00 BST on Monday.
West Yorkshire Police said the man carrying the rifle was seen with another man and a dog.
Wildlife officer Sgt Dave Lund said: "This is an appallingly cruel and unnecessary act and we are carrying out inquiries to find the person responsible and working with our colleagues from the RSPCA.
"We would like to hear from anyone who recognises the men in the images or who has any information that could assist the investigation."