Quaternary fossil faunas from caves in Takaka Valley and on Takaka Hill, northwest Nelson, South Island, New Zealand

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Abstract
The late Quaternary fossil vertebrate faunas from 43 caves in Oligocene limestones and Ordovician marbles in the Takaka Valley and on Takaka Hill, northwest Nelson, New Zealand, are described and discussed. Depositional environments are described and interpreted. Major sites, including Ngarua Cave, Hawkes Cave, Kairuru Cave, Hobsons Tomo, and Irvines Tomo are described in detail. Many sites on Takaka Hill have been damaged by casual collectors since their discovery around 1900. Most sites were pitfall traps, but some deposits had been redistributed by water. Two deposits were attributed to an accumulation of material from pellets ejected by laughing owls (Sceloglaux albifacies), and of these the spectacularly rich Predator Cave site provided a large sample of small vertebrates. The fossil faunas included 42 species of land snails, three species of leiopelmatid frog, a tuatara, three species of geckoes, one or more species of skink, at least 58 (including two introduced) species of bird, three species of bats, two rats and the house mouse. Eighteen radiocarbon dates show that the faunas of the Hill and the Valley sites were laid down during the past 30,000 years. The dates ranged from 400 ± 62 to 29,011 ± 312 yrs bp. The date of 29,011 ± 312 yrs bp, recorded from a specimen in Hawkes Cave, supplants the date of 25,070 yrs bp from Te Ana Titi as the oldest cave specimen known in New Zealand. The introduced birds plus one rat and the mouse were in laughing owl middens, indicating that deposition by this species continued into the late 1800s or early 1900s. Two distinct faunal assemblages were present in both areas. These demonstrate that there were regional extinctions due to climatic and associated environmental changes at the end of the Otira (last) Glaciation. In contrast to the continental regions, where humans were already present 10,000 years ago, and where the causes of post‐glacial megafaunal extinctions are subject to intense debate, no species became extinct in New Zealand until about 1000 years ago when humans arrived. The fauna from the last (Otira) Glaciation and Late Glacial periods (30,000 to 10,000 yrs bp), contained taxa typical of similar‐aged deposits at Oparara and farther south on the West Coast, and of Holocene deposits in the east and south of the South Island. The faunas in deposits of Holocene age (< 10,000 yrs bp) contained taxa typical of local forests at the time of European contact, plus extinct taxa. Some taxa were common to faunas of both ages. The Otiran and Late Glacial fauna were characterised by the moas Pachyornis elephantopus, P. australis, Euryapteryx geranoides and Megalapteryx didinus, but Anomalopteryx didiformis was present only in Holocene deposits. Dinornis struthoides and D. novaezealandiae were present in deposits of both ages. The duck Euryanas finschi, eagle Harpagornis moorei, and Aptornis and takahe Porphyrio mantelli were also found only in Otiran ‐ Late Glacial ‐ age deposits. Petrels were very rare in the Takaka area. Some samples of Anas chlorotis and Cyanoramphus spp. were large enough for statistical analysis, and the ranges in individual size, measured by lengths of various longbones, are presented and discussed for the fossil populations. Remains of some anatids, including Hymenolaimus, were common in Takaka Hill deposits at considerable distances from surface water, suggesting that these waterfowl were then more terrestrial than since mammalian predators arrived. Bones of three further individuals of Dendroscansor decurvirostris found in Hobsons Tomo constitute the third record for this taxon. The Hill and the Valley faunas are compared and discussed, and the regional fauna as a whole is compared with those from Oparara, the West Coast, Poukawa Swamp, Waitomo, and the Far North dunelands. The fossil faunas of Takaka Hill demonstrate that there has been no interchange of North and South Island terrestrial vertebrates over the last 30,000 years, and they therefore suggest that there was no Cook Strait land bridge at any time during the Otira Glaciation.