City animal control officials say test results show that antifreeze may be the culprit in the recent rash of pigeon deaths in downtown Chattanooga.
They said they could not say whether the pigeons had gotten the lethal liquid by accident or by someone's intent to kill them.
Officials first speculated that corn laced with poison might have been killing the pigeons.
No further outbreak of mass pigeon deaths has occurred.
City Animal Control said,
"Preliminary lab reports received on Tuesday, Nov. 14, indicate that the dead pigeons and corn showed no detectable residues of pesticides or avitrol, the commercial product used in pest control of pigeons.
"Corn samples did show a residue of ethylene glycol at a very low level. While the level was not a toxic level, it is an indicator that the corn may have been soaked in a product containing ethylene glycol as a primary ingredient, such as anti-freeze.
"More tests are being conducted to confirm the level and existence of ethylene glycol."