Mauritius Blue-Pigeon

Diet
Fruits and nuts were probably the mainstay of the Mauritius Blue Pigeon's diet, and like other blue pigeons, it may have occupied the upper canopy, and migrated seasonally to where food was available. Cossigny dissected a specimen in the mid-1700s and later sent it and its stomach contents to René Antoine Ferchault de Réaumur with a letter describing his findings. The gizzard and crop contained four "nuts", which Cossigny was told were the seeds of either Calophyllum tacamahaca or Labourdonnaisia calophylloides. The Comoro and Seychelles Blue Pigeons also feed on C. tacamahaca, and the strong gizzard of the former helps in the digestion of the seeds.

In 1812 Jacques Gérard Milbert provided the only description of the behaviour of the bird in the wild:

The claim that the bird fed on river molluscs has been criticised by James Greenway, as blue pigeons are principally arboreal, but other mainly frugivorous pigeons, such as species of Ptilinopus and Gallicolumba, do occasionally eat molluscs and other invertebrates. The two species of Nesoenas have also been reported as eating freshwater snails, and one was seen hunting tadpoles. Milbert may in any case have been referring to arboreal snails, as extant blue pigeons rarely land on the ground. A diet of snails would have provided the birds with calcium for egg production.

Calls
It is believed to have made a sound like "barf, barf" with a kind of cooing noise as well