Helmeted Hornbill | Solid Ivory In Its Skull | Dumb Stupid Birds #38

Clark's Nutcracker | The Bird That Plants Forests by Accident | Dumb Stupid Birds #51

The Clark's nutcracker buries between thirty thousand and a hundred thousand pine seeds every autumn, hauling them in a pouch under its tongue and remembering thousands of individual caches under deep snow for up to nine months. The forgotten ones grow. Every whitebark pine forest in the high American West was planted, seed by seed, by a plain gray bird with a brain the size of a peanut that was just trying to stash lunch. You forgot why you walked into the kitchen.

North Island Brown Kiwi | A Bird Pretending To Be A Mammal | Dumb Stupid Birds #50

The kiwi hunts by smell, the only bird with nostrils at the tip of its beak. It has whiskers, heavy marrow-filled bones, fur-like feathers, and two working ovaries. The female lays an egg up to 20 percent of its body weight, so large the bird has to stop eating to finish it. Its closest relative is the extinct elephant bird of Madagascar, meaning its ancestors flew here, looked around, and decided flight was not worth the effort.

Ruff | Three Males, One Frozen Gene | Dumb Stupid Birds #49

The ruff comes in three permanent kinds of male: one fights, one freeloads, and one disguises itself as a female to slip past both. Which one a ruff becomes is fixed before hatching, locked in a chunk of chromosome that flipped backwards around four million years ago. Inherit two copies and the embryo dies. It has balanced fighters, freeloaders and impostors at fixed odds since before our own kind existed.

Standard-winged Nightjar | Two Feathers, Three Birds | Dumb Stupid Birds #48

During breeding season, male standard-winged nightjars grow a single feather on each wing into a two-foot bare shaft with a flag on the end. In flight, the flags trail behind so precisely that one bird looks like three birds flying in formation. After about six weeks, the feathers shed, break off, or get bitten off by the bird itself. Then it goes back to looking like a dead leaf for ten months.

Egyptian Vulture | Threw Rocks Before You Did | Dumb Stupid Birds #47

The Egyptian vulture is two feet tall, weighs about four pounds, and breaks open ostrich eggs by picking up rocks and throwing them. It also eats the dung of cows, sheep, and goats to absorb carotenoids that turn its face bright yellow, because a yellower face is more attractive to other Egyptian vultures. Endangered. Invented percussive tool use without supervision. The ancient Egyptians called it the Pharaoh's chicken and painted it onto tomb walls.