The poisoning happened on Saturday, July 8, in Warminster Community Park, Township police said in a release.
Officers and animal control were called to the scene when a "number of birds" were found dead near feeders around the old Naval Air Development Center (NADC) tower on Bristol Road, the department said.
Investigators determined that feeders "contained poison" that was likely placed sometime Saturday morning. Authorities did not name the poison used but said it is "dangerous to both humans and animals."
Police have released images of the poisoned bird feeders, and say residents should avoid any similar-looking devices and call police if encountered.
Warminster police, Warminster animal control, and the Pennsylvania SPCA are investigating, the release adds.
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