The moorhen died after it was hit by a stone thrown by a group of young men in Newmillerdam.
In a post shared to Facebook, PSCO Colin Starford, a member of the Wakefield city team, appealed for information on the incident.
He said: "Wildlife Crime Team Officers are interested in any information which may assist in identifying a group of young males at Newmillerdam on Sunday 20th January 2019, who were witnessed throwing stones at the wild birds.
"One of the stones hit a Moorhen which later died of it’s injuries.
"If you saw the males and can help, please contact West Yorkshire Police on 101 and ask for a member of the Wildlife Crime Team from Wakefield."