The genus
Alectroenas was first described in 1840 by the English zoologist
George Robert Gray with the
Mauritius blue pigeon (
Alectroenas nitidissimus) as the
type species. The genus name combines the
Ancient Greek alektruōn, meaning "domestic cock", and
oinas, meaning "pigeon". The
Alectroenas blue pigeons are closely interrelated and occur widely throughout islands in the western
Indian Ocean. They are
allopatric and can therefore be regarded as a
superspecies. There are three extant species: the
Madagascar blue pigeon, the
Comoros blue pigeon, and the Seychelles blue pigeon. The three
Mascarene islands were home to one species each, which are all extinct; the Mauritius blue pigeon, the
Rodrigues blue pigeon, and the Réunion blue pigeon. The blue pigeons perhaps colonised the Mascarenes, the
Seychelles or a now submerged
hot spot island by "island hopping" and evolved into a distinct genus there before reaching
Madagascar. Their closest
genetic relative is the
cloven-feathered dove,
Drepanoptila holosericea, of
New Caledonia, which they separated from 8–9 million years ago. Their ancestral group appears to be the
fruit doves (
Ptilinopus) of
Southeast Asia and
Oceania. The genus contains five extant or recently extinct species: • †
Mauritius blue pigeon (
Alectroenas nitidissimus)
extinct •
Madagascar blue pigeon (
Alectroenas madagascariensis) •
Comoros blue pigeon (
Alectroenas sganzini) •
Seychelles blue pigeon (
Alectroenas pulcherrimus) • †
Providence blue pigeon (
Alectroenas sp.)
extinct Species possibly in the genus Two species that became extinct in prehistoric times may have belonged to this genus: • †
Rodrigues blue pigeon (
Alectroenas payandeei) • † Réunion blue pigeon (
Alectroenas sp.) The
Rodrigues pigeon (
Nesoenas rodericana), now extinct, was once assigned to the genus
Alectroenas, but this is now believed to be erroneous. In reality, it probably belongs to an undescribed genus, as the sternum's shape is very dissimilar in its details to that of
Alectroenas or
Columba, and indeed to any other living genus of pigeons and doves. It is most similar to that of the
Gallicolumba ground doves or to a miniature version of the sternum of a
Ducula imperial pigeon. The Réunion blue pigeon is known from the description of a slaty-blue feathered pigeon on
Réunion, given by
Dubois in 1674. Dubois mentions "wild pigeons, everywhere full with them, some with slaty-coloured feathering" which likely references the Réunion blue pigeon. Since the Réunion blue pigeon was only mentioned by Dubois, little is known about its extinction. The Réunion blue pigeon likely survived after 1683 and maybe even until 1703.
Jean Feuilley mentioned that all native pigeons were extinct in 1705. It is possible that invasive species such as cats and rats could have caused their extinction. ==Description==