Status, conservation, and management of the land snails of the genusPowelliphanta(Mollusca: Pulmonata)

Use of adhesives to attach devices to invertebrates: implications for depredation by ship rats (Rattus rattus)

“…Rats are effective predators, capable of taking large numbers of snails (Meads et al 1984). Therefore, any research tool that only slightly increases the successful location of land snails by rats could be damaging to a population in decline.…”

“…The ship rat (Rattus rattus) is a significant predator in New Zealand forests. In areas where rats are present, Powelliphanta are a frequent food source, and rat middens can contain vast quantities of Powelliphanta shells (Meads et al 1984). Rat depredations account for a high proportion of damaged shells of Powelliphanta traversi traversi (Devine 1997;Bennett et al 2002).…”

Rooks (Corvus frugilegus) dine on snails in Poland

“…For bigger snails, some bird species use their beaks to lever off pieces of the shell or apply a sharp blow to crack the shell (Mountainspring et al, 1990). This can be achieved by hammering or pecking with the beak, or by holding the snail in the beak and hitting it against a hard object (Heller, 1981;Meads et al, 1984). Some birds (e.g., Laridae and Corvidae) drop or throw snails onto hard objects (Zach, 1979;Cristol and Switzer, 1999;Allen, 2004).…”

Prehistoric predation of the landsnailPlacostylus ambagiosusSuter (Stylommatophora: Bulimulidae), and evidence for the timing of establishment of rats in northernmost New Zealand

“…arrival of rats in New Zealand is correct, then the fossil record should include evidence of extinctions of some small vertebrates and large invertebrates susceptible to rat predation dated to before human settlement, and also before the extinctions of moa and other large vertebrate taxa by human hunting and habitat destruction. Studies of contemporary New Zealand sites where the kiore is the only introduced mammal present indicate that it is a significant predator of medium and large-sized landsnails (Campbell et al 1984;Meads et al 1984;Atkinson 1986;Parrish & Sherley 1993;Brook 1999a). The present study examines evidence for prehistoric rodent predation of Placostylus (Maoristylus) ambagiosus Suter, a species of large landsnail endemic to northernmost New Zealand.…”

“…and possums (Tnchosurus vulpecula) has led to declines in populations of many medium and large-sized endemic New Zealand landsnails, and to the extinction of some landsnail populations (Powell 1938, Penniket 1981, Meads et al 1984, Moors 1985, Efford 1998, Brook & McArdle 1999 Most of the mammals listed above were introduced to New Zealand between the late 18th and late 19th centuries by Europeans (King 1990), but the kiore or Polynesian rat (Rattus exulans) was widely distributed in New Zealand before European contact It has long been thought that the introduction of the kiore to New Zealand was coincident with initial human colonisation (eg, Davidson 1984, Atkinson & Moller 1990, Roberts 1991 which, on present evidence, began c 750 years B P (Anderson 1991, McFadgen et al 1994, McGlone et al 1994, Higham & Hogg 1997, Newnham et al 1998, McGlone & Wilmshurst 1999) However, Holdaway (1996Holdaway ( , 1999a has suggested that the kiore first arrived in New Zealand nearly 2000 years ago, and more than 1000 years before permanent human settlement The evidence for early rat arrival is based on accelerator mass spectometry (AMS) radiocarbon dates on the gelatin fraction from rat bones collected from natural, mostly predator-accumulated deposits in carbonate-nch caves, which gave maximum ages of 2155 ± 130 years B P and 1930 ± 110 years B P for South Island samples, and 1775 ± 93 years B P for North Island samples The reliability of these dates has been questioned by * Department of Conservation P O Box 842 Whangarer New Zealand Anderson (1996), based on observed inconsistencies between AMS determinations on Rattus exulans collagen products compared with radiocarbon dates on other materials within a coastal dune sequence in southern New Zealand. Holdaway & Beavan (1999) subsequently argued that AMS ages on unweathered bones from cool, stable, carbonate cave environments are reliable.…”