Blood test shows rodenticide likely killed young great horned owl in Hyde Park

Andrew Joslin reports test results show a fatal dose of a commonly used rodenticide in the blood of a young great horned owl found on the ground under its nest near the DCR swimming pool and rink on Turtle Pond Parkway in Hyde Park earlier this month.

He reports that rescuers who found the owlet rushed it to an wildlife treatment facility in Gloucester, but it was too late - the bird died ten minutes after arrival.

The owlet was lethargic and had an extremely pale mouth and tongue. On handling it bled freely from a wing. It had been on the ground for approximately 6 hours before capture.

He says one of the chemicals found in the bird's blood was bromadiolone, a "second-generation anticoagulant rodenticide" now commonly found in bait traps, which works by making them bleed out, basically. Rats ingest the stuff, but don't die immediately, so leave the traps in a weakened state, making them more vulnerable to raptors, which eat them, increasing their own odds of dying from the chemical.

In February, a bald eagle found in Arlington died from ingesting one of the chemicals.