Quaternary fossil faunas, overlapping taphonomies, and palaeofaunal reconstruction in North Canterbury, South Island, New Zealand

This paper describes the late Quaternary fossil fauna from the area within a 10 km radius of Waikari, North Canterbury, New Zealand. Fossils from a pitfall deposit (Waikari Cave), ten predator sites attributed to laughing owls Sceloglaux albifacies (notably Ardenest, Gowan Hills Owl site, and P. Lamb's Owl site), five swamp sites (notably Pyramid Valley and Glencrieff), and three archaeological sites, contributed most of the data. A few specimens came from coalluvial deposits in rock shelters. A small fauna is described from alluvial deposits along Home Creek, near Waipara. The age of these faunas includes the Late Pleistocene (Otira Glacial) for the Home Creek fauna, Late Glacial — early Holocene for Glencrieff, and Late Holocene for Pyramid Valley swamp, Waikari Cave, and all predator sites. Some of the predator sites accumulated fauna until late in the nineteenth century.

The total avian fauna for the Waikari region (including Glenmark) comprises 65 indigenous and 4 introduced species of birds. In addition, tuatara Sphenodon spp., two species of gecko Hoplodactylus spp., including the large H. duvaucelii, undetermined skinks and fish, two species of bats Mystacina spp., three rodents Mus musculus, Rattus norvegicus and (most common) Rattus exulans, and European rabbits Oryctolagus cuniculus were found. All introduced species were in deposits accumulated by laughing owls.

The derivation of faunas from the diverse taphonomic processes of cave‐pitfall trapping, swamp‐miring / lacustrine accumulation, and predation, has resulted in an unusually broad perception of the composition of the Late Holocene fauna. This fauna differs in relative frequency of species from the much wetter regions of the West Coast and Takaka. It also differs from Mt Cookson in North Canterbury, which is closer to mountains, at higher altitude, and wetter than the Waikari district. The Waikari moa fauna was dominated by Dinornis giganteus, Emeus crassus, Euryapteryx geranoides, and Pachyornis elephantopus. Among smaller terrestrial birds, kiwis Apteryx spp. and wekas Gallirallus australis were less common than in wetter regions. Finsch's duck Euryanas finschi, paradise shelduck Tadorna variegata, extinct coot Fulica prisca, extinct gallinule Gallinula hodgenorum, laughing owl Sceloglaux albifacies, and adzebill Aptomis defossor were common in contrast to their absence or near‐absence in the west. Snipe Coenocorypha cf. aucklandica and piopio Turnagra capensis were noticeably more common in Waikari faunas than in more western ones.

The Otiran moa fauna comprised the same species as in the Holocene, except that Pachyornis elephantopus was more common. Comparisons between the large, well‐dated, samples from Glencrieff and Pyramid Valley, show that P. elephantopus but not E. crassus exhibited post‐glacial dwarfing in this region.

The importance of predator sites in palaeofaunal reconstruction is indicated by the fact that 17 bird species and virtually all non‐bird taxa were recognised solely from these deposits. These include five procellariiforms, and three river‐bed inhabitants Charadrius bicinctus, Thinornis novaeseelandiae, and Sterna albostriata. In these faunas the abundance of two species that live or lived in open shrublands and grasslands, the extinct quail Coturnix novaezelandiae and pipit Anthus novaeseelandiae is positively correlated with the abundance of kiore Rattus exulans in the late Holocene. While quail and pipit dominated the late-Glacial to early Holocene small-bird fauna of Glencrieff indicating the presence of shrubland at that time, these species were virtually absent from the well-represented pre-rat fauna of the latest Holocene in Pyramid Valley, Waikari Cave, and older predator sites. Forest was established, at least in low altitudes, in the Waikari region about 5,000 years ago. The marked increase in abundance of these birds after the arrival of kiore reflects the increased presence of shrublands in the area following human arrival and anthropogenic burning.

Their absence in the extensive late Holocene faunas from around Waikari strongly suggest that pukeko Porphyrio melanotus, swamp harrier Circus approximans, and shoveler duck Anas rhynchotis were not part of the prehuman New Zealand fauna.

Fossil insect faunas were obtained from three laughing owl sites. Nineteen species of weevils and 22 species of other ground beetles were represented. These showed that the former ranges of several now-relict species, most notably Amychus ?granulatus, Mecodema costellum lewisi, Anagotus stephenensis,A. rugosus, and Ectopsis ferrugalis, were considerably more extensive in the past.

Faunas are listed from two sites near the study area. The fauna from Mimiomoko Pocket, Waipara River, was re-examined and recognised as having been accumulated by laughing owls, and found to include several small passerines. Puffinus Cleft, Nape Nape Scenic Reserve on the adjacent North Canterbury coast, contained abundant bones of Puffinus griseus. A specimen list is given for bones retrieved over the years from Glenmark Swamp and still surviving in New Zealand collections.

Keywords:

• fossil vertebrates
• fossil insects
• taphonomy
• Quaternary palaeofauna
• Waikari
• North Canterbury
• New Zealand

Notes

Palaeofaunal Surveys, 43 The Ridgeway, Nelson, New Zealand.

Zoology Department, University of Canterbury, Private Bag 4800, Christchurch, New Zealand.