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NUMBER 89 119
TABLE 3.—Lists of characteristic species of the Anomalopteryx and
Euryapteryx assemblages that respectively characterize the closed-canopy
wetter forests typical of western areas in the Holocene and the forestshrubland-grassland
mosaics of the drier eastern areas, when these species
occur together in abundance.
Anomalopteryx assemblage Euryapteryx assemblage
Anomalopteryx didiformis
Dinornis novaezealandiae
Apteryx australis
Strigops habroptilus
Anas chlorotis
Gallirallus australis
Callaeas cinerea
Philesturnus carunculatus
Pachyplichas jagmi/yaldwyni
Xenicus longipes
Petroica australis
Euryapteryx geranoides
Euryapteryx curtus
Emeus crassus
Dinornis giganteus
Pachyornis mappini/elephantopus
Pachyornis australis (uplands only)
Megalapteryx didinus (uplands only)
Cnem iorn is gracilis/calcitrans
Euryanas finsch i
Aptornis otidiformis/defossor
Gallinula hodgenorum
Fulica prisca
Harpagornis moorei
Coturnix novaezelandiae
tered. Acanthisittid wrens of several species are abundant in
deposits (when conditions of preservation permit), and the New
Zealand Robin {Petroica australis) and Saddleback {Philesturnus
carunculatus) are abundant. It is important to note that
these species are found in faunas deposited under vegetational
mosaics but are relatively rare and infrequent, in contrast to
their numerical abundance and dominance of faunas from areas
where the vegetation was a closed-canopy forest. It is therefore
not presence or absence so much as relative frequency that is
important in the definition of this assemblage. In contrast, the
mere presence of species listed in the Euryapteryx assemblage
indicates the presence of open habitat.
NORTH CANTERBURY.—The Mt. Cookson study area occupies
an intermediate zone between the wetter west and the drier
east and, as expected, does not exhibit the same degree of faunal
turnover. The drier climate of eastern areas is probably responsible
for the delay of the establishment of closed-canopy
forest until about 6000 years ago, much later than in the west.
During the latter stages of oxygen isotope stage 3 and the early
part of stage 2, Pachyornis elephantopus dominated moa faunas
on Mt. Cookson but was associated with rare remains of
Dinornis giganteus, D. struthoides, Megalapteryx didinus,
Emeus crassus, and Euryapteryx geranoides. During the coldest
period of the last glacial, however, P. elephantopus was virtually
the only moa living in these and other eastern landscapes,
where loess was being deposited. But, as in the west,
with warming temperatures and forest establishment in the late
Holocene, Anomalopteryx didiformis and Dinornis novaezealandiae
came to dominate the faunas. Unlike in the west,
however, Euryanas finschi and Aptornis defossor remained
common in the late Holocene fauna, perhaps because the forests
remained much drier.
THE TYPICAL EASTERN FAUNAS.—In contrast to the above
faunas, those of the lowlands in North and South Canterbury
and North Otago provide no evidence for any faunal turnover
in the period spanning the last glacial to the late Holocene. The
greatest change detected is a reversal of dominance roles within
the same suite of species: whereas Emeus crassus, Euryapteryx
geranoides, and P. elephantopus were the main emeids
throughout this time, Pachyornis elephantopus dominated glacial
faunas, but Emeus crassus was the most common during
the Holocene. Dinornis giganteus and D. struthoides were the
dominant dinornithids during the glacial and the Holocene.
In these eastern lowlands, there is no evidence of local extirpation
of taxa at the end of the glacial period, as there is for
western regions. The lack of glacial faunas containing smaller
birds limits comparisons of faunal turnover to moas. Because
there are no drastic changes in the moa faunas, however, and
because Cnemiornis, Harpagornis, and Aptornis are known to
have frequented the Otiran landscapes, and continued to do so
in the Holocene, we can speculate on the composition of the associated
fauna. These larger birds are part of the Euryapteryx
assemblage that frequented Otiran western landscapes. So, as
in the west, Euryanas finschi, Gallirallus australis, Nestor notabilis,
New Zealand Crow {Corvus moriorum), New Zealand
Pipit {Anthus novaeseelandiae), New Zealand Quail {Coturnix
novaezelandiae), Piopio {Turnagra capensis), Fulica prisca,
and Gallinula hodgenorum were probable associates of Cnemiornis,
Harpagornis, and Aptornis in Canterbury.
The relative abundance of species in late Holocene faunas of
the east differs from that of western areas. This partly results
from eastern areas having a much greater diversity resulting
from the continued presence of all the presumed Otiran species
during the Holocene, when other species typical of forest habitats
became established. Such species include Kakapo {Strigops
habroptilus), Philesturnus carunculatus, and Petroica
australis. These species, however, are all relatively rare compared
to their abundance in western faunas. Differences in the
frequency of a species can usually be explained by the availability
of the preferred habitat of that species. For example, the
grassland inhabiting quail, Coturnix novaezelandiae, had little
or no habitat in the west during the Holocene and is rare there,
but in the east it is common. The most common passerine in
late Holocene deposits in eastern areas was Turnagra capensis,
which suggests that the preferred habitat of this extinct bird
was the shrubland mosaics of drier areas. This is supported by
the observation that Turnagra is present in fossil deposits of
western areas only in Otiran deposits, when shrubland habitats
were widely available.
THE CENTRAL OTAGO FAUNAS.—The few data available for
the Otiran fauna of central Otago indicate Pachyornis elephantopus
and Dinornis giganteus were the most common moas,
with Cnemiornis calcitrans being the only known carinate. The
abundance of the last species in these deposits and in Otiran
loess deposits in Canterbury illustrates its preference for the
open, short shrubland/grassland habitats prevailing at that time.
The Holocene moa fauna of central Otago is most similar to
eastern ones, but it is influenced by altitude. In the broad valleys,
Emeus crassus is common, and E. geranoides and P. ele-