On 5 April 2009 in a Wal*Mart parking lot in McGregor, McLennan County, Texas an adult male great-tailed grackle (Quiscalus mexicanus) was observed chasing an adult deer mouse (Peromyscus maniculatus). A deer mouse was walking across the edge of the parking lot when a great-tailed grackle that had been sitting on a tree limb at the parking lot edge landed near the deer mouse. The deer mouse ran under a car with the grackle in pursuit. The mouse ran around the tire in a clockwise direction three or four times with the grackle following. The mouse stopped behind the wheel under the car and the grackle stopped on the opposite side of the tire and waited. After a short delay the deer mouse switched direction and ran counter clockwise around the tire and the grackle followed closely behind. This lasted for two or three times and with the grackle getting closer the deer mouse jumped up into the wheel well and after approximately two minutes the boat-tail grackle gave up and flew off. The deer mouse was not observed leaving the safety of the car. This attempted predation lasted approximately five minutes.
The great-tailed grackle is reported to eat grain, insects, small fish, lizards, snails, tadpoles, and plant materials. Some eggs and bird nestlings (Davis and Arnold, 1972; Johnson and Peer, 2001). This is the first known observation of an attempted predation by a great-tailed grackle on a living mammal.