Abstract/Summary

Global biodiversity is declining at a rate comparable to previously documented mass extinctions and does not appear to be slowing despite extensive global collaboration in the academic community and policy change targets. This decline is expected to be greatest in terrestrial ecosystems due to anthropogenic factors particularly in two of the most pervasive forms of land change undertaken by humans; urbanisation and agricultural intensification which will lead to further significant changes in the species composition of ecological communities and abundance of species. For example, the West-European hedgehog (Erinaceus europeaus) population is declining substantially across its range as a result of anthropogenic activity, which is explored here. The degree to which the rural environment has been altered may impact the survival of hedgehogs. As hibernation has previously been described as a high-risk time, overwinter survival and nesting behaviour in the rural, human-dominated landscape was investigated at two contrasting sites. Hedgehogs consistently nested near hedgerows, roads and woodlands, but avoided pasture fields. Differences between the sites were evident for arable fields, amenity grassland and buildings, such that different land management practices might influence hibernation success. Significant differences in survival and percentage mass loss between the two sites indicated that such land management practices may impact upon survival of hedgehogs, although mortalities occurred in autumn and spring, indicating winter is not the high-risk time previously described. Whilst the value of woodland to hibernating hedgehogs was evident over-winter, methods for detecting hedgehogs in such complex habitats are limited. Therefore, the effectiveness of three methods (infra-red thermal camera, specialist search dog, spotlight) for detecting hedgehogs were compared in three different habitats. Significantly more hedgehogs were detected, and at greater distance, using the camera and dog than the spotlight in amenity grassland and pasture although no hedgehogs were detected in woodland. This could indicate that all three methods are not suitable for surveying in this habitat or that hedgehogs typically avoid woodlands during the summer and autumn, potentially as a strategy to avoid badgers. To further explore the cause of mortality of hedgehogs, data from wildlife hospitals were analysed. Anthropogenic factors were responsible for up to 47% of admissions, whilst 51% of animals survived to release. Survival was highest for orphans (63%) but lowest for anthropogenic causes (39%). Comparatively few large hospitals (>250 hedgehogs year-1) exist, but care for the majority of hedgehogs. The wild population is increased by an estimated 4-6% of the pre-breeding population nationally by rehabilitators, suggesting rehabilitation could have a marked benefit ameliorating some of the negative impacts of humans.