Dodo

The dodo (Raphus cucullatus) was a large, flightless bird native to Mauritius, a remote volcanic island in the Indian Ocean east of Madagascar and the African mainland. Human arrival in the late sixteenth century marked the beginning of the end for this species, which vanished within little more than sixty years. Because no complete dodo specimens survive, our understanding of its appearance and biology relies on scattered skeletal remains, a handful of preserved soft tissues, and the drawings and descriptions left behind by sailors, merchants, and early naturalists.

Historical depictions often show the dodo as a rotund, almost comically overweight bird. This image is partly the result of artistic exaggeration and partly due to the fact that many illustrations were made from captive birds that were overfed and kept in unsuitable conditions. The dodo likely had greyish‑brown plumage, somewhat coarse or shaggy in texture, with lighter primary feathers on its small wings. A distinctive tuft of curly pale feathers rose from its rump. The head was largely naked and grey, giving it a vulture‑like appearance, while the beak showed bands of green, yellow, and black. Its legs were sturdy and yellowish, ending in strong black claws suited for walking and digging.

Naturalists long struggled to classify the dodo. Its proportions were particulary mystifying: a massive body, tiny wings, and a formidable beak made it resemble almost anything except a pigeon. As a result, the bird was often placed in several different groups.

Many biologists suspected a connection to pigeons and doves, noting similarities in skull structure and leg anatomy. Also, microscopic examination of the few surviving head feathers revealed structural similarities to those of pigeons. However, others argued that the dodo must be related to birds like ostriches, emus, and cassowaries, simply because these birds were also large and flightless. Some proposed links to waterfowl, pointing to the dodo’s robust legs and terrestrial habits, while others suggested turkeys or other gamebirds.

A breakthrough came when researchers extracted genetic material from a mummified dodo specimen preserved at the Oxford University Museum of Natural History. DNA sequencing finally settled the long‑standing debate: the dodo was a highly specialized, flightless member of the pigeon family[1].

Its closest living relative is the Nicobar pigeon (Caloenas nicobarica), a bird with iridescent green‑yellow plumage and a mane of elongated black feathers. The two species diverged more than 40 million years ago.

Scientists now believe that the ancestors of the dodo were (flying) pigeons that reached Mauritius by riding monsoon winds across the Indian Ocean. Once on the island, they encountered an ecosystem with abundant food and no (mammalian) predators. Under those conditions, natural selection favoured birds that grew larger, became more terrestrial, and gradually lost the ability to fly. This process is a classic example of island gigantism, in which isolated species evolve oversized bodies and reduced defensive traits.

The dodo’s closest extinct relative was the Rodrigues solitaire (Pezophaps solitaria), another large, flightless pigeon that lived on Rodrigues, an island east of Mauritius. The solitaire survived slightly longer than the dodo but ultimately succumbed to the same pressures: hunting, habitat destruction, and introduced animals.

[1] Shapiro et al: Flight of the dodo in Brevia – 2002. See here.