False eyes

"This Northern Pygmy-Owl appears to have eyes in the back of its head. But why? One theory is that large false eyes may create the illusion that the owl is much bigger than its 6 and 3/4-inch size. A more current theory is that the false eyes help protect the pygmy-owl's true eyes. Small birds will mob this diurnal owl, even striking it, directing some attacks at its eyes. If the large false eyes can take the brunt of these attacks, little harm will come to the Pygmy-Owl's vulnerable true eyes." From BirdNote.

birdnote.org/show/pygmy-owls-false-eyes

It has been amazing, watching this tiny, popcan-sized owl that has become a celebrity in my city. Much of the time, it sits at or near the top of very tall trees, often for an hour or two. Then it will fly and land high up in a different tree and do the same, and occasionally, if one is lucky, it might just fly down to a somewhat lower branch or very briefly to the bushes. If one is even luckier, it might fly down to the snow-covered ground and catch a Meadow Vole.

"The Northern Pygmy-Owl may be tiny, but it’s a ferocious hunter with a taste for songbirds. These owls are mostly dark brown and white, with long tails, smoothly rounded heads, and piercing yellow eyes. They hunt during the day by sitting quietly and surprising their prey. As a defensive measure, songbirds often gather to mob sitting owls until they fly away. Mobbing songbirds can help you find these unobtrusive owls, as can listening for their call, a high-pitched series of toots." From AllAboutBirds.

www.allaboutbirds.org/guide/Northern_Pygmy-Owl/id

en.wikipedia.org/wiki/Northern_pygmy_owl