Haigh et al (2012) Habitat use of the European Hedgehog
Title: Habitat use by the European hedgehog (Erinaceus europaeus L. 1758) in an Irish rural landscape, Irish Naturalists’ Journal: All-Ireland mammal Symposium. 2008
Authors: A.J. Haigh, F. Butler & R.M. O’Riordan
Country: Ireland
Background to study
An examination of habitat use by hedgehogs and how this is influenced by prey availability in rural Ireland.
Method
- Between June and November 2008, 14 hedgehogs were marked with heat shrink tubes and reflective tape and the nightly movements of 10 animals were monitored every 10 minutes by spotlight surveys for 23 nights within 43 ha of mixed farmland consisting of arable (35%), pasture (41%), residential (8%) and small areas of woodland and scrub.
- All individuals were classified as adult or juvenile based on weight and hind-foot measurements (juveniles < 600 g and <36 mm respectively with growing spines evident).
- Animals were injected with a Passive Integrated Transponder (PIT tag) and those captured after 28 September were fitted with radio tags to monitor hibernacula (see Haigh et al. (2013) Habitat selection, philopatry and spatial segregation in rural Irish hedgehogs (Erinaceous europaeus), Mammalia DOI 10.1515.)
- To measure prey availability, 6 x 60 m long and 46 cm wide transects were walked and the surface prey counted each night during October 2008.
- Habitat use by each individual and seasonal shifts were analysed by plotting location data within ArcGIS and calculating the length of time observed per habitat type over time.
Key results
- Hedgehog density was 3.07/ha and consisted of nine adults (6 males, 3 females) and five juveniles (3 males, 2 females).
- Males and females reached their heaviest weight prior to hibernation (October) and when both sexes were combined, their weight was significantly heavier during this time than earlier in the year.
- No hedgehogs were observed in coniferous woodland.
- Hedgehogs shifted their use of habitat across seasons.
- In July and August, hedgehogs were located garden on 31% and 63% of observations respectively.
- In October, 72% of observations occurred in the arable field which had been cut the previous month and those active in November remained within this habitat.
- When in arable land, hedgehogs spent significantly more time in the centre of the field than along the field verge and in the lower portion of the field than in the upper section which concurred with the significantly higher density of potential surface prey observed in the lower part of the field.
- In July and September, hedgehogs spent significantly more time in pasture than in other months.
- In August, the garden was used to a significantly greater extent than the rest of the year.
- Hedgehogs started to enter hibernation from 19th October when they entered scrub, pasture and garden.
- Slug species were the most abundant (90%) of surface invertebrate observed within the arable field.
- Badgers were seen on six occasions and predated one hedgehog within the arable field which suggests that hedgehog preference for arable fields was driven by food resources and not predation risk.
Key messages to landowners and managers derived from these results
- Mixed farming in rural landscapes is likely to enhance hedgehog populations due to the diversity of habitat types and prey availability that is exploited by hedgehogs at different times during summer activity.
- Winter stubble and beetle banks are likely to enhance the suitability of arable land for hedgehogs by increasing the prey availability and providing more cover from predation.
- Conifer woodlands may act as barriers to dispersal between local hedgehog populations and thus creating wide rides with deciduous trees, shrubs and grassland within large conifer woods may help to facilitate the use of this habitat by hedgehogs.