predation

Two conservation tools have been developed over the last 10–15 years for species on the New Zealand mainland that are vulnerable to introduced mammalian predators: landscape-scale predator trapping networks, and eradication of predators within mammal-proof exclosures. We tested whether these tools would allow population growth of critically endangered grand skinks (Oligosoma grande) and Otago skinks (O. otagense) over three years.

Opportunities now exist to establish pest-free areas on the mainland of New Zealand by eradicating introduced mammals from within predator-proof-fenced areas. This has increased opportunities to investigate how the native insect fauna responds to the eradication of introduced mammals. We examined the response of weta populations to mammal eradication in a before-after-control-impact (BACI) experiment within the southern exclosure on Maungatautari.

Reintroduction programmes need to be monitored as a way of gauging potential causes of their success or failure. This, in turn, can be used to improve the likelihood of future translocation success. Since the 1990s, stitchbird (or hihi: Notiomystis cincta) translocations have been intensively monitored, with comparisons between two of these projects (Tiritiri Matangi Island – a successful introduction, and Mokoia Island – an unsuccessful introduction) often compared and contrasted as a means of identifying factors important in translocation success for this species.

Compared with the effect of invaders on the native terrestrial fauna of New Zealand, interactions between native fishes and introduced trout (sports fish in the genera Salmo, Oncorhynchus and Salvelinus) are less well known and there have been fewer efforts to remedy their effects. Trout have caused widespread reductions in the distribution and abundance of native galaxiid fishes, a family dominated by threatened species.

The stomach contents of 158 hedgehogs captured at Macraes Flat, Otago, New Zealand, over two summers in 2000 and 2001 were examined for the occurrence of lizards. The remains of at least 43 skinks (both Oligosoma nigriplantare polychroma and O. maccanni) and one gecko (Hoplodactylus sp.) were found. Twenty-one percent (n = 33; 8 males and 25 females) of the examined hedgehogs had fed on skinks. Female hedgehogs ate significantly more skinks than did males.

Indigenous peoples’ knowledge on changes in wildlife populations and explanations for these changes can inform current conservation and wildlife management systems. In this study, Tūhoe Tuawhenua interviewees provided mātauranga (traditional knowledge) about a repertoire of visual (e.g. decreasing flock size), audible (e.g. less noise from kererū in the forest canopy), and harvest-related (e.g.