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 .
Elf owl
The elf owl ("Micrathene whitneyi") is a member of the owl family Strigidae, that breeds in the southwestern United States and Mexico. It is the world's lightest owl, although the long-whiskered owlet and the Tamaulipas pygmy owl are of a similarly diminutive length. It is also the world's smallest owl. The mean body weight of this species is . These tiny owls are long and have a wingspan of about . Their primary projection extends nearly past their tail. They have fairly long legs and often appear bow-legged. They can often be heard calling to one another just after dusk or at sunset. Their call is a high-pitched whinny or chuckle. The male and female dart around trees and call back and forth.