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96 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOGY
FIGURE 9.—Lower mandibles of Eudyptes spp. (left lateral views). Top to bottom: Eudyptes pachyrhynchus
(MNZ 24546); Eudyptes, species undescribed (MNZ S30440, PRM sample # 15/92), from Kaingaroa, Chatham
Island; Eudyptes sclateri (MNZ 18897). Total length of MNZ S30440 is 119.1 mm.
THE COMPOSITION OF THE CHATHAMS AVIFAUNA
It is not possible to produce an entirely accurate catalog of
the living and extinct birds of the Chathams because in many
cases doubts have been raised (and may always exist) over reported
occurrences of several taxa. The exact composition of
the terrestrial and freshwater bird fauna is particularly difficult
to ascertain. Several of the 45 recorded species appear to
have been included by various authors as a result of errors of
identification or locality (see van Bemmelen, 1993:32),
whereas others, regarded by some as members of the indigenous
Chathams fauna, seem more likely to have been introduced
by humans.
Taxa that I exclude from the analysis of living and extinct
fauna are considered below.
Apteryx sp. (kiwi): Travers (1866:358) stated that "formerly
an apterix [sic], said by the Maoris to have been identical
with a New Zealand species, and... a smaller species of the
same bird...were found [in the Chathams], but have become
extinct...." Hutton (1904), as had Wallace (1893), accepted
this statement and included Apteryx in his catalog. Travers
(1873:213), however, commented that his son "has now reason
for believing that the weka..., the kakapo..., and the kiwi...
were erroneously assigned to [it]" and later (Travers,
1883:183) that he himself was "not disposed to accept [these
records]." No fossil bones of Apteryx have been found in the
Chathams, and the record must remain unsubstantiated.
Gallirallus australis (Weka): Bones, reportedly identical
to those of this species, have been recovered from several sites
on Chatham Island, leading to the possibility that wekas were
indigenous in the Chathams prior to the introduction of G. australis
hectori in 1905 (Turbott, 1990). There is no unequivocal
evidence that any of these bones predate the European introduction.
A mounted specimen of a Weka in the Rijksmuseum
van Natuurlijke Historie, Leiden (Temminck collection, accessioned
in 1823), is said to be from the Chatham Islands, but this
locality information may be spurious (van Bemmelen, 1993).
On biogeographic grounds it seems highly unlikely that a population
of Gallirallus australis, identical to the mainland form,
would have evolved independently on the Chathams. If association
with pre-European middens could be demonstrated, the
most likely explanation would be that the species was taken to
the Chathams from mainland New Zealand by the original Moriori
inhabitants. Because there are no reports of Europeans
having seen the species prior to 1905, it would seem that the