Amsterdam wigeon

Amsterdam duck was barely larger than a thrush

Both Amsterdam Island and Saint Paul are more than 3,000 kilometers away from continents. Yet, or perhaps because of this, the islands were often visited by early sailors and their accompanying animals, leading to the extinction of all endemic birds there before they could be scientifically described. This includes the small, flightless Amsterdam wigeon, which was only described in 1996 based on bone findings by ornithologists Storrs Lovejoy Olson and Pierre Jouventin.

The Amsterdam wigeon was mentioned in writing much earlier: In 1696, William de Vlaming noted that he believed he had seen “two four-footed animals, resembling a weasel or a fox” in the reeds of Amsterdam Island. Zoologists W. R. P. Bourne, A. C. F. David, and C. Jouanin interpreted de Vlaming’s sighting in a 1983 article as Amsterdam duck. They are confident that it could not have been a mammal, as mammals only arrived later on the island through sailors and whalers. However, British ornithologist Julian P. Hume suggests in Extinct Birds (2017) that de Vlaming might have also seen rats.

Another written mention comes from the British historian John Barrow; in 1793, he reported seeing a “small, brown duck” on Saint Paul Island that was barely larger than a thrush. For comparison, the common European song thrush (Turdus philomelos) reaches a body length of 20 to 22 centimeters.

The Amsterdam wigeon differed in size and its reduced wings from all other known duck species. The only similar duck species is the larger, flightless Auckland teal (Anas aucklandica), a dabbling duck (Anatini) from the subantarctic Auckland Islands. The Amsterdam duck’s beak was very short and rounded at the tip, placing it most likely in the genus Mareca, which also includes the Eurasian wigeon (M. penelope).

The first bones of the Amsterdam duck were found in 1955 and 1956, described by scientists as similar to the bones of the European gadwall (Anas strepera). In 1987, further bones from at least 30 individuals were found, indicating a small duck with a short beak. The strong legs, reduced breastbones, and wings suggested flightlessness.

From the bones, it was also discerned that the Amsterdam wigeon drank little saltwater, suggesting that the bird likely did not live along the coast. The bones were recovered 500 meters above sea level.

Amsterdam wigeon – Fact sheet

Alternative name	Amsterdam Island duck, Amsterdam duck
Scientific name	Mareca marecula, Anas marecula
Original range	Amsterdam Island, probably also Saint Paul Island (Indian Ocean)
Date of extinction	End of the 18th century
Causes of extinction	Overhunting, animals introduced to islands

Amsterdam wigeon: Uncertain island home

It remains unclear whether the extinct Amsterdam duck was endemic solely to Amsterdam Island or also occurred on Saint Paul Island. Since all known bones of the Amsterdam wigeon have been found on Amsterdam Island in the southern Indian Ocean, scientists currently believe that this duck species was native there.

However, John Barrow’s report comes from the neighboring Saint Paul Island, making it uncertain whether the duck described by Barrow was just a similar species or if the Amsterdam duck indeed inhabited both islands.

The distance between the two islands is only 80 kilometers. Olson and Jouventin believe that birds living on one island could very well have lived on the other as well.

Bones only a few hundred years old

The International Union for Conservation of Nature (IUCN) dates the extinction of the Amsterdam wigeon to the end of the 18th century. Additionally, the bones described by Olson and Jouventin are not older than a few hundred years.

Barrow’s report provides a possible clue to the extinction of the Amsterdam wigeon. He wrote that the duck was the “preferred food source of the five seal hunters living on the island.”

Since the bones suggest that the duck could not fly, it would have been easy prey for hunters. Animals living on islands, in the absence of human civilization, are usually not very wary (a phenomenon known as island tameness).

Although the Amsterdam and Saint Paul Islands are largely uninhabited today, as they were in the past, Olson and Jouventin point out the islands’ strategically advantageous position between Africa and Australia. Therefore, they likely were often visited by whalers and sailors. These visitors probably not only hunted the Amsterdam duck and possibly other endemic birds but also introduced foreign animal species and carried out slash-and-burn clearings.