The Legend of Crocodiles and the Egyptian Plover

Many people grow up with a familiar image: a crocodile resting on a riverbank in the sun, its jaws wide open while small birds enter its mouth to clean its teeth. Among the birds often associated with this story are the Egyptian plover (Pluvianus aegyptius) and the spur-winged lapwing (Vanellus spinosus). Because of this supposed behavior, the Egyptian plover has long been nicknamed the “toothpick bird” or the “crocodile bird.”

Nile crocodile and Egyptian plover（圖片來源：Henry Scherren，CC0 1.0 公共領域）

In reality, this image is very likely a long-standing legend rather than an observed biological interaction. To date, no modern field observations have verified that local birds actually maintain such a mutualistic relationship with crocodiles. Even the images circulating online are largely manipulated or staged. The origin of this story can be traced back to the ancient Greek writer Herodotus. In his work Histories, he recorded a report he had heard from people living along the Nile: a bird known as the Trochilus supposedly formed a cooperative relationship with crocodiles. According to Herodotus, crocodiles often harbored leeches in their mouths, and the Trochilus would remove these parasites, benefiting both species.

Later writers including Aristotle, Pliny the Elder, and Aelian repeated this account in their own works, allowing the story to circulate widely through classical literature. The description became so influential that even the 11th edition of the Encyclopaedia Britannica mentioned the phenomenon, most likely perpetuating a chain of repeated reports rather than direct observation. The idea that the mysterious Trochilus corresponds to the Egyptian plover is itself a later interpretation derived from these ancient descriptions.

Egyptian plover（圖片來源：Luc Viatour，採用 CC BY-SA 3.0 授權）

Spur-winged lapwing（圖片來源：Lip Kee，採用 CC BY-SA 2.0 授權）

Herodotus's accounts, however, are not always considered reliable by modern historians and scientists. In the same book, he described another curious creature said to inhabit the deserts of India: the so-called “gold-digging ants.” These animals were said to be furry, roughly the size of foxes, and capable of digging through sand dunes in ways that exposed grains of gold, which local people would then collect and sell. Later scholars suggested that Herodotus may actually have been referring to the Himalayan marmot (Marmota himalayana), a burrowing rodent known from that region. Marmots indeed dig extensive tunnels, but their appearance differs greatly from that of ants. The story likely arose from secondhand reports, misunderstandings, or translation errors between languages and cultures.

Giant ants chasing gold hunters in The Indian Gold Hunters（圖片來源：Abbott, Jacob，CC0 1.0 公共領域）

Himalayan marmot（圖片來源：Christopher J. Fynn，採用 CC BY-SA 3.0 授權）

Returning to the supposed partnership between crocodiles and birds, modern biological research has not confirmed any mutualistic relationship between crocodiles and species such as the Egyptian plover. Even if such an interaction were ever to occur, it would likely represent an extremely rare and incidental event rather than a consistent ecological behavior. For this reason, treating the famous “crocodile bird” story as a myth is a reasonable conclusion.

Author: Shui-Ye You

Reference:

Herodotus. (430 BC) .Histories