These are some very noisy yellow headed blackbirds. Usually, their migration pattern does not bring them this far east in Kansas, but extends from Mexico in the the winter to the northwestern United States and Canada during the summer. Sometimes a storm or extreme winds will force them off of their established routes north and south. Mature males have yellow heads and chests, and females and very young males are a very dark brown or black. They have loud, hoarse calls and can empty a bird feeder in a matter of minutes. Before moving to Kansas, I had never seen this type of blackbird.