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.
LEGISLATIVE CONTEXT: The law designating the willow ptarmigan as the official Alaska state bird is Section 44.09.060 of the Alaska Statutes, specifically Title 44 (State Government), Chapter 09 (State Seal, Flag, and Emblems), Section 060 (State Bird).