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32 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY
Without any justification, Rothschild (1907) placed this form
in the genus Necropsittacus of Rodrigues and described it as N.
borbonicus.
Family STRIGIDAE
Genus Mascarenotus Mourer-Chauvire, Bour,
Moutou, and Ribes
Mascarenotus grucheti Mourer-Chauvire, Bour,
Moutou, and Ribes, 1994
Gmchet's Mascarene Owl
FIGURE 13^
MATERIAL.—Grotte des Premiers Francais. Holotype: r.
tarsometatarsus, 1993-49. Paratypes: 1. humems, 1993-50; r. p.
tibiotarsus, 1993-48; r. d. tibiotarsus, 1993-47.
Grotte de l'Autel: r. tarsometatarsus, 330537; r. d. tarsometatarsus,
330538.
Grotte "au sable": 1. quadrate, 330809; 1. p. femur, 330737.
Marais de l'Ermitage: r. tarsometatarsus, 1800.
REMARKS.—We have not found any additional remains other
than those used in the original description of Mascarenotus
grucheti (Mourer-Chauvire et al., 1994). We have placed all
the Mascarene strigiforms in the extinct genus Mascarenotus,
which resembles the genus Otus but presents some distinctive
morphological characteristics. This genus includes one species
on Mauritius, Mascarenotus sauzieri, based on Strix sauzieri
Newton and Gadow, 1893 (synonyms, Otus commersoni Oustalet
(1896), Strix newtoni Rothschild (1907)), one species on
Rodrigues, Mascarenotus murivorus based on Strix {Athene)
murivora Milne-Edwards (1874) (synonym, Bubo (?) leguati
Rothschild (1907)), and one species on Reunion, Mascarenotus
grucheti Mourer-Chauvire et al., 1994.
The tarsometatarsi of M. grucheti are very close in size to
those of M. sauzieri, although the only humems known from
Reunion is clearly smaller than those of M. sauzieri, for which
we have a good sample of comparative material (12 specimens).
The ratio of element lengths (Mourer-Chauvire et al.,
1994, fig. 1) shows M. sauzieri to be strikingly parallel to modem
insular species of the genus Otus, such as Otus lawrencii
(Sclater and Salvin), or O nudipes (Daudin), from the West Indies,
in which the legs are much more elongated than in continental
forms. The same adaptation is found in the four extinct
insular species of the genus Grallistrix, from Hawaii, which is
derived from the genus Strix (Olson and James, 1991). In the
Strigiformes, as well as in the genus Accipiter, this lengthening
of the legs corresponds to an adaptation for catching birds on
islands lacking terrestrial mammals.
This species must have had a very secretive life in the forests
or remote areas, because the early explorers of Reunion never
spoke of nocturnal raptors, although eared owls were noted historically
on the other Mascarene Islands.
Family STURNIDAE
Genus Fregilupus Lesson
Fregilupus varius (Boddaert, 1783)
Reunion Starling
MATERIAL.—Grotte des Premiers Francais: 1. d. femur,
1993-57.
REMARKS.—This passerine femur agrees in size and morphological
characteristics with what is known of the Reunion
Starling. On the posterior face, the proximal edge of the internal
condyle ends internally with a point that projects proximad.
On the internal face, the internal condyle is anteroposteriorly
compressed. This characteristic accentuates the shape of the
external condyle, which looks very protmding, and the rotular
groove on the anterior face is deep, as was indicated by Murie
(1874), who described the only known skeleton of this species.
The distal width (7.2 mm) and the distal depth (5.8 mm) agree
with a femur the total length of which ranges from 31.6 mm
(Berger, 1957) to 35.6 mm (Murie, 1874) or 37 mm (Gunther
and Newton, 1879).
The Reunion Starling became extinct between 1838 and
1858 (Barre and Barau, 1982).
Relationships, Origin, and Fate of the Reunion Avifauna
The avifauna found as fossils on Reunion differs from that of
the other two Mascarenes (Table 13) in that, with the exception
of Dryolimnas augusti, none of the species had lost their ability
to fly.
Lacking on Reunion are the most distinctive Mascarene
birds, namely, the dodo and solitaire {Raphus, Pezophaps), the
large flightless rails {Aphanapteryx, Erythromachus), and the
large parrots with enormous bills and atrophied wings {Lophopsittacus
mauritianus, Necropsittacus rodericanus) (Newton
and Newton, 1876; Gunther and Newton, 1879). Among
the forms that perhaps had lost the ability to fly is the Oiseau
bleu, placed by Olson (1977) in the genus Porphyrio, and
which was either an extinct species of that genus or a population
of the modem species Porphyrio porphyrio (Linnaeus).
Dubois (1674) said that it could not fly, but in 1724 Father
Brown said that it was able to fly, but rarely and just above the
ground (Barre and Barau, 1982, our translation). The authenticity
of Father Brown's report has been questioned (Lougnon,
1970, 1992), but Cheke (1987) thinks that his report comes
from an unidentified but authentic source. Remains referable to
Oiseau bleu are yet to be found, so we know nothing more
about it.
The other genera represented on Mauritius and Rodrigues by
species with reduced flying ability are represented on Reunion
by species with normal flying ability. This is the case for Nycticorax,
with the flying species N. duboisi, and for Falco duboisi,
the coracoid and ulna of which are not reduced, unlike that
of F. punctatus, of Mauritius. The other extinct species, namely