Cold agglutinin disease. Cold agglutination - at body temperature, the antibodies do not attach to the red blood cells. At lower temperatures, however, the antibodies react to Ii antigens, bringing the red blood cells together, a process known as agglutination.
American Robin (Turdus migratorius). The robin red breast was designated as the state bird of Michigan by House Concurrent Resolution No. 30, the Senate concurring, on April 8, 1931.
Some larger birds like owls, hawks, and eagles may begin courting in December and nest in January and February. Other birds that winter in Michigan or elsewhere in the northeast may begin to sing and scout for good nesting territories as early as January. Bird feeders may contribute to a bird deciding to nest early in your yard.