Birds
Limpkin
Aramus guarauna · also called limpkin, crying bird, carrao
The limpkin is a lanky brown wading bird of American marshes with a diet of almost pure snails and a voice that has been unnerving people for centuries. Its wild, wailing scream, given in the dark, sounds so much like someone in distress that it has been woven into folklore, ghost stories, and, more recently, the soundtracks of jungle films.
Overview
The limpkin lives in freshwater marshes, swamps, and wooded wetland edges from the south-eastern United States through the Caribbean and Central America to much of tropical South America. It is 64–73 cm long, dark olive-brown spotted and streaked with white, with long legs and a long, slightly downcurved bill. It is the only living member of its family, sitting between the rails and the cranes.
A snail specialist
The limpkin eats almost nothing but apple snails and other large freshwater snails. Its bill tip is often slightly open and curves a little to the right, matching the right-handed spiral of a snail shell, so the bird can slip it in, cut the muscle holding the snail, and draw the body out whole — leaving the shell intact in tidy piles.
The call
Its cry is a loud, rasping wail, repeated and far-carrying, given mostly at night and dawn. It has fed folklore across the Americas, and is one of the sounds layered into the classic Tarzan yell.
Status
The limpkin is Least Concern and increasing. Long confined in the US to Florida, it has spread rapidly north and west since around 2017, following the invasive island apple snail — a rare case of a native specialist gaining from an introduced species.
Limpkin: common questions
Why does the limpkin scream like that?
The loud, wailing cry is the limpkin's main long-distance signal, used to hold territory, keep in contact with a mate, and respond to disturbance, and it is given most often in the dark hours around dusk, night, and dawn. To human ears it carries an unsettling resemblance to a child crying, a woman screaming, or an animal in agony, which is why the bird has picked up names like crying bird and why it appears in ghost stories and warnings of ill omen across its range. There is nothing sinister behind it; it is simply a very loud bird with a harsh voice, doing what many wetland birds do less dramatically.
How does a limpkin eat a snail without smashing the shell?
Very precisely. A limpkin picks up an apple snail, carries it to firm ground or a perch, and positions it with the opening facing up. Its long bill has a slight rightward curve and a small gap near the tip that fit the geometry of the snail's shell and its operculum, the trapdoor the snail uses to seal itself in. The bird works the bill tip past the operculum, snips the columellar muscle that anchors the snail to its shell, and then pulls the whole soft body out in one piece. It does this so cleanly that the discarded shells are usually intact, and a favoured feeding spot builds up a conspicuous midden of them.
Is the limpkin a heron, a rail, or a crane?
None of them exactly. It is the only living species in its own family, the Aramidae. Genetic and anatomical evidence places that family within the same broad group as the rails and the cranes, and the limpkin looks and behaves a bit like both, being roughly the size and shape of a large rail or a small crane, wading and probing like a heron, and flying with its neck outstretched and slow, deliberate wingbeats like a crane. So it is best thought of as a crane-and-rail relative that has gone its own way and specialised on snails.
Why is the limpkin suddenly turning up outside Florida?
Because its food supply has expanded. For decades the limpkin in the United States was tied to Florida, where native apple snails live. Since the early 2000s a larger, faster-breeding South American apple snail, introduced through the aquarium trade, has spread through wetlands across the south-eastern states and beyond. Limpkins have followed it, and since around 2017 the birds have been recorded breeding well north and west of their old range, in states where they were once great rarities. It is an unusual situation in which an invasive species has directly benefited a native bird.