A spokeswoman for the Philadelphia Zoo says one of four peacocks that escaped from the zoo has been found dead on a highway.
Dana Lombardo says the animal was found Thursday on Interstate 76 and likely had been hit by a car.
Zoo staffers are working with authorities to locate the remaining peacocks.
The zoo says the flock roams freely on its grounds, and it is cared for by veterinary staff. The zoo says the birds sometimes venture past its gates, but they normally return home on their own.
Lombardo says it's unusual for the animals to travel that far from the zoo, since they do have a homing sense.
The birds were spotted walking on Interstate 76 around 8:30 p.m. Wednesday. State police arrived and shut down two lanes of traffic on the highway, causing backups for miles.