Hummingbird
Hummingbirds are birds native to the Americas and constitute the biological family Trochilidae. They are among the smallest of birds, most species measuring in length. Indeed, the smallest extant bird species is a hummingbird, the bee hummingbird weighing less than .
Coscoroba swan
The coscoroba swan ("Coscoroba coscoroba") is a species of waterfowl endemic to southern South America. It is the smallest of the birds called “swans”, but still a large species of waterfowl. It belongs to the subfamily Anserinae in the family of ducks, swans, and geese, Anatidae. It is placed in the monotypic genus "Coscoroba". The coscoroba swan is traditionally considered as an early branch from the common ancestor leading to true geese and swans, and recent genetic studies have associated a phylogenetic relationship between this species and the Cape Barren goose ("Cereopsis novaehollandiae") as sister groups.