Even though the hummingbird is extremely small in size, they have the most feathers per square inch of any other bird. An average size hummingbird has approximately 940 feathers. Hummingbirds have no down feathers and thus loose body heat quite rapidly. The nornal body temperature of a hummingbird is 105 degrees, but at night when in a state of torpor it can drop to approximately 66.2 degrees. Hummingbird feathers are iridescent and therefore require sunlight to show color.