Mascarene Teal

The Mascarene teal was a small duck, and in comparison with the extant ducks of Madagascar, it was larger than Bernier's teal but smaller than Meller's duck. Based on the known bones, the sternum was 27.7 mm (1 in) wide and 21.7 mm (1 in) deep, the coracoid 41.1–42.5 mm (2–2 in) long, the humerus 69.6–73.1 mm (3–3 in) long, the ulna 63 mm (2 in) long, the tibiotarsus 71 mm (3 in) long, and the tarsometatarsus 42 mm (2 in) long. While overall most similar to the Sunda teal, the Mascarene teal differs in that the carina of the sternum (a keel-like ridge) projects further forwards, and the lower manubrial spine (a projection from the sternum) is narrow and elongated in the Sunda teal, and more elongated than in the Mascarene teal. The coracoid of the Mascarene teal is very similar to that of the Sunda teal. They both share a small, upwards directed spike on the internal side of the coracoid's hind surface, followed by a small depression. On the coracoid's front surface, near the acrocoracoid's (an upwards expansion of the coracoid) internal side, there is an almost circular muscle scar (for the attachment of muscles) in both species. The humeri of the Mascarene and Sunda teal look very similar, with the humeral head (the upper, expanded part of the bone) forming a well-developed rim over the tricipital fossa (a depression), with a well-developed and elongated pectoral attachment. …

Mourer-Chauviré and colleagues stated in 1999 that the proportions of the Mascarene teal's limb-bones are very similar to those of the Sunda teal, indicating no reduction in flight capability, and are very different from those of flightless species like the Auckland teal (Anas aucklandica) and the Amsterdam wigeon (Anas marecula). It is possible that the Mascarene teal had normal flight capabilities and was able to fly between Mauritius and Réunion, explaining how it occurred on both islands. Hume and the British ornithologist Michael Walters added in 2012 that it may also have moved seasonally. Cheke and Hume suggested in 2008 that, like the related Bernier's and Indo-Australasian teals, the Mascarene teal possibly nested in tree holes, as did the local starlings and parrots. Many other endemic species of Mauritius and Réunion were lost after the arrival of humans, so that the ecosystems of these islands are severely damaged and hard to conserve. Before humans arrived, the islands were entirely covered in forests, very little of which remains today because of deforestation. The surviving endemic fauna is still seriously threatened. On Mauritius, the Mascarene teal lived alongside other recently extinct birds such as the dodo, the Mauritian sheldgoose, the red rail, the broad-billed parrot, the Mauritius blue pigeon, the Mauritius scops owl, and the Mauritius night heron. …