Restoration initiatives of ecosystems transformed by human actions require optimisation of eradication measures of introduced species, particularly in fragile insular ecosystems. We studied aspects of the spatial ecology of introduced feral cats (Felis catus) on subantarctic Auckland Island of New Zealand to assist eradication efforts of pests from this remote, biologically rich island. Firstly, we estimated home range sizes and identified core areas of activity based on movement-rooted dynamic Brownian bridge models.
Over the past six years studies have been carried out, mainly in dense podocarp stands of Pureora and Pouakani Forests, to gather information about the periodicity, abundance, and soundness of seed crops, the animals that disperse or destroy seed, and how they do so. The ultimate objective is to find out what part each bird, rodent or insect plays in assisting or limiting regeneration of timber 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.
Damage by introduced brushtail possums (Trichosurus vulpecula) to Pinus radiata trees was assessed in 41 compartments of a commercial forestry plantation on the Coromandel Peninsula, New Zealand. All the trees assessed were less than 3 years old. Possum damage in the compartments was low (median prevalence 3.3%) but highly variable (range 0–30%). Eight of 37 measured habitat factors differed significantly (P < 0.05) between the sites with damaged and undamaged trees.