Slaty-backed Gull - 27 Dec 2022

A dark-mantled gull identified as a Slaty-backed Gull (Larus shistisagus) was reported yesterday at Grace Lake in the Visteon Complex off of I-275 and Ecorse Rd in Wayne County.  This morning Brian Beauchene refound the bird among hundreds of Ring-billed and Herring Gulls on the frozen ice of the lake.

I showed up shortly after noon and found a dozen birders with scopes on the sleeping Slaty-backed Gull. Though legs were concealed the large gull showed a smudgy head and dark mantle that differentiates it from the clean white head of a Great Black-backed Gull snoozing in the background. 

Nearby a Lesser Black-backed Gull was stretching and showing its yellow legs, smudgy head and smaller size relative to the Slaty-backed Gull. 

When the Slaty-backed Gull finally woke up we could see its pink legs and the large white window on the P10 primary. The string of pearls were also visible as it stretched its wings. 

A close look at the flesh-colored bill reveals a bright yellow tip above the red and black gonydeal spot.

BirdLife International labels the Slaty-backed Gull as a species of least concern. Its distribution is mainly found along the Korean Peninsula northward to Alaska, but birds routinely can be found along both coasts and the Great Lakes.

eBird distribution is shown below:

A nice life history writeup can be found at Birds of Korea. More information regarding life cycles of the bird can be found here.