FREEDOM TOWNSHIP, MI - Police believe a family of swans killed Wednesday, Aug. 10, on a road near Ann Arbor were deliberately run over and they are investigating the incident.

The Washtenaw County Sheriff's Office responded to Parker and Scio Church Road for a report of five swans dead on the side of the road.

"With the evidence left at the scene, it appears they were deliberately ran over. There were good tire tracks left at the scene," said Sgt. Keith Flores.

Police believe the swans were struck by the vehicle between 7:15 a.m. and 8 a.m. Wednesday. Investigators believe the vehicle ran off the right side of the road, close to the edge of the water, and hit the swans.

Tire tread marks indicate the vehicle is a truck or Jeep with 18- to 20-inch wheels. The tires are 13.5 inches wide, police say.

The Washtenaw County Sheriff's Office, Michigan Department of Natural Resources and Humane Society of Huron Valley are investigating the incident.

The family of swans from a pond near Parker and Scio Church roads in Freedom Township in July 2016.

Scio Township resident Emily Bauerle reported the dead swans to police.

She had driven by the area daily, and enjoy watching the swans and their cygnets in recent months.

Wednesday morning, she drove by and saw the swans were dead and it appeared a vehicle had run them over.

"It saddens me that people can't leave nature alone," she said.

The birds were trumpeter swans, which are a threatened species in Michigan. The more common yellow-billed mute swans are an invasive species from Europe, according to the DNR.

Trumpeter swans, identifiable by their solid black beaks, disappeared from Michigan for 100 years after settlers destroyed their marsh habitats and killed the birds for their down. The species has reappeared because of Michigan's Trumpeter Swan Restoration Program.

If anyone has information about the incident, they can call the Washtenaw County Sheriff's Office tip line at 734-973-7711.