12 of the World's Smallest Birds (Photo Gallery)

Willow Tit: Despite its small size, the willow tit likes cold weather. Found in sub-arctic Europe and northern Asia, the willow tit is a tiny 4.5 inches long on average and weighs 0.31 to 0.38 ounces — making it about the same size as its neighbor the marsh tit. They look almost exactly alike as well. They do, however, have very different vocalizations.