ST. IGNACE, Mich. (WJMN) — The Straits Area Audubon Society’s annual count of birds near the Mackinac Bridge noted a record number of redhead ducks.

(SAAC)‘s annual Christmas Bird Count shows not only the quantity of birds but also helps track different avian species. This year’s CBC was held on Dec. 21, having been postponed a week due to high winds.

A group of eight birders set out at dawn to record the birds within a 15-mile diameter circle, the midpoint centered on the Mackinac Bridge. Forty-seven different species were counted, totaling 8,700 birds.

Among those were 7,000 redhead ducks.

A group of ducks floating together is called a raft.

With an escort from bridge personnel, the ducks could be photographed. According to the SAAC, a raft of ducks is often misreported by people on the bridge as a possible oil slick.

The SAAC also reports the most difficult problem was estimating numbers when the ducks are packed so tightly that individual birds cannot be discerned.