Urbanisation causes fragmentation of natural habitats, which results in loss of biodiversity, while promoting an environment that can facilitate invasive species. However, forest fragments are an important refuge for native species and therefore understanding and mitigating threats in fragments is critical.
The feeding behaviour of four adult caged hedgehogs was studied for a period of 22 weeks. The maximum feeding activity of all four animals occurred between 1900 and 2200 hours, and two of them showed a second, but minor, peak of activity about 0300 hours. Individual feeds were of short duration with the first feed each evening tending to exceed the mean. Variations in behaviour between individuals were considered to be a function of their differing body weights, or to be related to the size of the sample.
A population of hedgehogs (Erinaceus europaeus L.) in pasture land in Canterbury was found to vary between less than four and eight per hectare. Feeding habits were studied through stomach contents and analysis of faeces. Grass grub beetles (Costelytra zealandica) and porina moths (Wiseana cervinta), both important pasture pests, were relatively important food items. Estimates of the number of grass grubs eaten in relation to their density and that of hedgehogs in pastures show that hedgehogs are potentially capable of consuming 10-40 percent of adult populations.
European hedgehogs (Erinaceus europaeus) have recently been identified as a conservation threat in New Zealand. Hedgehogs were kill-trapped at 14 wetland and braided riverbed sites in the upper Waitaki Basin between late October 1997 and early February 1998 and their gut contents described. The most commonly eaten prey were Coleoptera (present in 81% of 192 guts), Lepidoptera (52%; n = 192), Dermaptera (49%; n = 192), Hymenoptera (42%; n = 192) and Orthoptera (31%; n = 319).
Efficient detection techniques will confirm the presence of a species at a site where the species exists, and are essential for effective population monitoring and for assessing the outcome of management programmes. However, detection techniques vary in their ability to detect different species. A wide range of mammalian predator species, most introduced into New Zealand since the late 18th century, have had a detrimental impact on the native flora and fauna.
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.
Investigations of nest predation are often limited by the researchers’ inability to identify nest predators accurately. I tested a chemical bait marker, Rhodamine B (RB), as an indicator of egg predation at artificial ground nests. In a pen trial, the presence of characteristic fluorescent bands in one or more facial vibrissae from all treatment animals confirmed the suitability of RB as a bait marker in the introduced European hedgehog (Erinaceus europaeus).