The Seriema is the last living relative of the prehistoric terror birds

Nature · Published 3 October 2026 Swipe more like this →

In short: These long-legged, ground-dwelling birds of South America are the closest modern kin to the extinct, massive predators known as terror birds. While they possess the ability to fly, they prefer to spend their days running through grasslands and scrub, occasionally hunting snakes by smashing them against hard surfaces.

The seriema family, Cariamidae, represents the final surviving lineage of the order Cariamiformes. These birds are primarily found across the southern and central regions of South America, including nations like Brazil, Argentina, and Uruguay. They are divided into two distinct species: the red-legged seriema, which favors open grasslands, and the black-legged seriema, which prefers scrub and woodland environments. Physically, they are characterized by their long necks, tails, and legs, alongside short wings that reflect their terrestrial lifestyle.

Their evolutionary history is particularly striking, as they are considered the closest living relatives to the Phorusrhacidae, or terror birds, which were massive, flightless carnivores that once roamed the Americas. While the fossil record for the seriemas themselves is limited, researchers have identified prehistoric species like Chunga incerta and Miocariama patagonica from the Miocene of Argentina. Other ancient fossils, such as those from the Eocene Messel pit, have been suggested as potential relatives, though their precise classification remains a subject of ongoing scientific debate.

Ecologically, the seriema functions similarly to the African secretary bird. They are opportunistic hunters, consuming insects, rodents, and reptiles. When capturing prey like lizards, they employ a violent technique of beating the animal against the ground to break its bones. Beyond their predatory habits, they play a role in nutrient cycling by consuming detritivores. Despite being capable of flight, they typically only take to the air to escape predators or reach their nests, which they construct in trees at heights of one to five meters.

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