Feeding behaviour of the European hedgehog (Erinaceus europaeus L.) in a New Zealand pasture

Abstract

The feeding behaviour of the European hedgehog (Erinaceus europaeus L.) has been investigated in a pastoral environment. Sampling methods that caused the minimum interference to the natural population were used. The relative importance of the various prey species in the diet were analysed by occurrence, relative volume and direct counting techniques. Problems often associated with the use of direct counting were successfully overcome. It was established that the main animal food items in the hedgehog diet were earwigs, lepidopteran larvae, beetles, harvestmen, dung flies, slugs, and earthworms. Small quantities of a large number of other species were also consumed. Several variations in the diet were found to be related to changes in the availability of food species. Although hedgehogs are capable of consuming large numbers of grass grub beetles (Costelytra zealandica) during the flight season it is concluded that they are unlikely to provide any effective measure of biological control of this pasture pest. Hedeghog diet was not influenced significantly by the sex of the animal, or by pasture irrigation. It was demonstrated that the feeding rhythm of captive animals, fed under laboratory conditions, was similar to that observed in the field.

Observation showed that hedgehogs were active for an average of eight hours per night, with a period of maximum activity between 9 p.m. and 11 p.m. Animals tended to follow relatively fixed routes on successive nights.

Excluding nestlings, the population density in an irrigated clover-ryegrass pasture was found to vary from four (winter) to eight (summer) animals per hectare. The average minimum feeding range of these animals was 2.4 hectares, although their feeding ranges overlapped considerably.