A little owl peeps out from a hole in a sycamore tree as dusk falls in a dry West Texas river bottom. It’s an Elf Owl, the world’s smallest owl species.
The Elf Owl is a little bird that stands less than six inches tall and weighs less than an ounce and a half, about the same as a golf ball.
And it’s a ruthless hunter. At dusk, the Elf Owl emerges from its tree hollow to hunt beetles, crickets, and spiders, as well as the occasional lizard or mouse.
Larger prey, like scorpions, may even be stored in the nest for later consumption once the stingers have been removed.
Elf Owls may be found in woods and desert cactus environments in southwest Texas and southern Arizona. 
They commonly nest in woodpecker holes in tall saguaro cactus in desert areas.
Elf owls, like other owls, are silent yet deadly. Airflow across the bird’s wings usually produces a rushing sound. 
However, owl wings contain little extensions on the front edge and a fringe of feathers on the rear edge that minimize sound by breaking up the airflow.
Soft feathers on the wings and legs absorb almost all of the residual noise. Critters have no idea what’s coming until it’s too late.
They leave the United States in October for Mexico’s warmer latitudes, where insects are more plentiful in the winter.
In the American Southwest, however, spring arrives early, and the little owls return in late February or early March, eager to begin their nesting season.
Females deposit one to four eggs in the spring, which hatch in three weeks.
Dad brings food back for mom and the chicks at first, but after a few weeks, mom also goes food hunting to feed the expanding brood.
Elf owls prefer to escape rather than fight, however, predators such as great horned owls have been seen to be mobbed by them.
A few elf owls dive-bomb the larger owl, making loud alarm sounds, and soon additional birds join in, sometimes of different kinds.
