When it comes to dating, the male Costa's Hummingbird really has to go above and beyond. In this clip from a new PBS Nature documentary airing tonight, one eager male reveals a mating display that's equal parts shocking, impressive, and somewhat terrifying. While the Squid Head look might seem bizarre even for the world of birds, for the female Costa’s, it’s simply irresistible. Like most avian suitors, male Costa’s Hummingbirds are experts at showboating. Typically, though, they woo their mates by hovering in the air before nosediving while giving off a high-pitched whistle. The mating behavior shown in this Nature preview is actually quite rare to see, says Kenn Kaufman, bird expert and 吃瓜黑料 field editor. “I lived in Arizona for a long time and had Costa's Hummingbirds in the backyard, and I only glimpsed this kind of display a couple of times at a distance,” he says. Kaufman thinks the display might be used during peak courtship, just before the pair...