The Rodrigues night heron (Nycticorax megacephalus) is an extinct species of heron that was endemic to the Mascarene island of Rodrigues in the Indian Ocean. The species was first mentioned as "bitterns" in two accounts from 1691–1693 and 1725–1726, and these were correlated with subfossil remains found and described in the latter part of the 19th century. The bones showed that the bird was a heron, first named Ardea megacephala in 1873, but moved to the night heron genus Nycticorax in 1879 after more remains were described. The specific name megacephala is Greek for "great-headed". Two related extinct species from the other Mascarene islands have also been identified from accounts and remains: the Mauritius night heron and the Réunion night heron. The Rodrigues night heron was robust, its bill was comparatively large, stout and straight, and its legs were short and strong. It is estimated to have been 60 cm (24 in) long, and its appearance in life is uncertain. There was marked sexual dimorphism, males being larger. Little is known about the bird's behaviour, but the contemporary accounts indicate that it ate lizards (probably the Rodrigues day gecko), was adapted to running, and although able to fly, rarely did so. Examinations of the known remains have confirmed its terrestrial adaptations; one researcher thought the species flightless but this idea has not been accepted by others. The species could not be found by 1763, and it is thought to have been driven to extinction by human-related factors such as the introduction of cats.
Taxonomy The French traveler Francois Leguat mentioned "bitterns" in his 1708 memoir A New Voyage to the East Indies about his stay on the Mascarene island of Rodrigues from 1691–93. Leguat was the leader of a group of nine French Huguenot refugees who settled on Rodrigues after they were marooned there. Leguat's observations on the local fauna are considered some of the first cohesive accounts of animal behaviour in the wild. In 1873, the French zoologist Alphonse Milne-Edwards described subfossil bird bones from Rodrigues he had received via the British ornithologist Alfred Newton. These had been excavated in 1865 under the supervision of his brother, Colonial Secretary Edward Newton, by the police magistrate George Jenner, who found the specimens in a cave on the Plaine Corail, near Rodrigues solitaire remains. Milne-Edwards correlated the bones with the "bitterns" of Leguat's account, but found that they were instead consistent with belonging to a species of heron, whose large head and short legs made it understandable that it was compared to a bittern. He considered the skull different from all other herons in size and shape, but found the tarsometatarsal foot bone similar to that of the extant heron genus Ardea, and therefore named the new species Ardea megacephala. The specific name megacephala is Greek for "great-headed", and references the large head and jaws of this species. The bones examined by Milne-Edwards included the skull, tarsometatarsus, tibiotarsus (lower leg bone), femur (thigh-bone), sternum (breast-bone), coracoids (part of the shoulder-girdle), humerus (upper arm bone), and metacarpals ("hand" bones). The holotype specimen (the specimen the specific name and original scientific description is attached to) is an incomplete but probably associated specimen catalogued as UMZC 572 at the Cambridge University Museum of Zoology. This specimen since appears to have lost a humerus, a dorsal rib, both femora, a tibiotarsus, and both tarsometatarsi. In 1875, A. Newton correlated references to "bitterns" with the heron in the then recently rediscovered 1725–26 account of the French sailor Julien Tafforet, Relation de l'Ile Rodrigue, which he thought confirmed Milne-Edwards's conclusions. More fossils were obtained from caves by the palaeontologist Henry H. Slater in 1874, and these were described by the German zoologist Albert Günther and E. Newton in 1879, with the benefit of bones not known at the time of Milne-Edwards's original description. They included the two last cervical vertebrae (of the neck), fifth dorsal vertebra (of the back), pelvis, scapula (shoulder blade), ulna (lower arm bone), radius (lower arm bone), second phalanx of the inner toe, and first of the hind toe. These bones are now part of the collection of the Natural History Museum, London. Günther and Newton did not find it necessary to describe these bones, as they were the same form as in other herons, particularly the night heron genus Nycticorax, and they therefore transferred the Rodrigues species there, as Nycticorax megacephalus. In 1893, E. Newton and the German ornithologist Hans Gadow referred to the bird as Ardea (Nycticorax) megacephala, and the British zoologist Walter Rothschild used the original name Ardea megacephala in 1907, while noting that he was inclined to believe the three extinct Mascarene herons (which had previously been assigned to either Ardea or Butorides) all belonged in Nycticorax. The Japanese ornithologist Masauji Hachisuka concluded in 1937 that this species was little related to any other heron, and moved it to a new genus as Megaphoyx megacephala. He also used the common name "Rodriguez flightless heron", due to his conviction that it had lost the ability to fly. In 1953, Hachisuka used the name "flightless heron" and added that this species was "quite remarkable" among herons, and not closely related to any other heron, extant or extinct. The American ornithologist Pierce Brodkorb kept the species in Nycticorax in 1963.
… excerpt ends here. Continue reading the full article.
