Lots of bird species perform bizarre and beautiful courtship displays, but few can match the surreal spectacle of a male Costa's hummingbird:

Filmed for a new PBS Nature program, "Super Hummingbirds," this clip reveals the male's elaborate efforts to woo a female. The first 40 seconds are impressive but not especially strange, with green feathers shimmering on his back as he dances and flits around his potential mate. Then we see him from the female's perspective.

His iridescent purple face feathers, which normally lie flat, are now protruding from his head like tentacles. The facial transformation makes it look like he's wearing a mask, which vaguely resembles a shiny purple octopus or maybe Cthulhu.

Like other courtship displays, from actual peacocks to peacock jumping spiders, this eerie mask evolved as a way for females to assess the fitness of males. Sparkly face tentacles might not seem to reveal much useful information about a suitor, but mating rituals like these are often bewildering to human observers.

"Hummers may be the smallest birds in the world," PBS notes in a statement about the new show, "but what they lack in size, they make up in speed and the ability to adapt in ways we're just beginning to learn about as they continue to evolve."

Native to the Southwestern U.S. and Western Mexico, Costa's hummingbirds (Calypte costae) are desert dwellers, feeding on nectar from plants like agave, fairy duster and desert lavender. They sometimes flee the desert's summer heat for cooler chaparral, scrub or woodland habitats, according to the National Audubon Society, but nest in the desert during late winter and spring, when this courtship occurs.

We may still not know exactly what female Costa's hummingbirds are looking for in a mate, but we do know this one has high standards. Despite the male's earnest dancing and eerily beautiful face, she decided he wasn't up to snuff.

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

This hummingbird is ready for Halloween
A new video captures the unique courtship display of a male Costa's hummingbird, which seems to involve a purple Cthulhu mask.