Pluvianellidae – Magellanic plover

The Magellanic plover (Pluvianellus socialis)—the sole member of the family Pluvianellidae—stands out among shorebirds for a variety of reasons beyond just its unique lineage. One of its most striking differences is its unexpectedly pigeon-like appearance: whereas most shorebirds have slender bodies and longer bills, the Magellanic Plover sports a short, slightly thicker bill and a rounder body, giving it a more dove-like silhouette. Its soft gray upperparts and faintly pinkish legs add to this uncharacteristic look, making it an easy bird to single out if you know what to look for.

Behaviorally, it distinguishes itself with a fascinating foraging method known as “foot trembling.” While scanning the lakeshores and salt flats for tiny invertebrates, the Magellanic Plover rapidly vibrates its feet against the sandy or muddy ground. This action disturbs insects, crustaceans, and other prey hidden just beneath the surface, prompting them to move and become easier targets. Although a few other bird species also use foot trembling, it remains a fairly rare strategy among shorebirds.

An even more unusual trait is its ability to produce a milky fluid—often called “crop milk”—to feed its chicks. This characteristic is extremely uncommon among birds outside the pigeon and dove family, emphasizing the Magellanic Plover’s distinctiveness. By secreting this nutrient-rich substance from the lining of its crop, the parent can nourish its offspring even when food is scarce.

In addition to these notable features, the Magellanic Plover’s limited distribution across southern Chile and Argentina and its preference for harsh, windswept environments only heighten its status as an ecological oddity among shorebirds.