Intra- and interhabitat differences in hedgehog distribution and potential prey availability

Abstract

With little previous research on the European hedgehog (Erinaceus europaeus Linnaeus) in Ireland, 22 hedgehogs (16 females and six males) were tagged at a rural Irish site between June 2008 and November 2009. Transect, surveying surface invertebrates were carried out in the centre and hedgerow in arable and pasture lands distributed throughout the site. In both years, hedgehogs selected arable land and this coincided with a rise in invertebrate density. This and the fact that within the arable field hedgehogs concentrated their activity where there was a greater density of potential prey suggest that hedgehogs learn the spatial location of prospective food. Contrary to other research, in most of the hedgehogs’ home range, individuals consistently foraged in the centre of both pasture and arable lands. Potential prey was lower in fields where the hedgerow had no bramble understory, and this suggests that hedgerow with good ground cover acts as an important reserve for invertebrates. Badgers (Meles meles Linnaeus) were seen on 12 occasions within the hedgehogs’ home range and they did not appear to have a negative effect on the hedgehogs’ use of the site. It was concluded that the main factor affecting the hedgehogs’ distribution within each habitat was the availability and accessibility of potential prey

Habitat selection, philopatry and spatial segregation in rural Irish hedgehogs (Erinaceus europaeus)

“…Hedgehogs remained in this habitat in October, both foraging and day-nesting there (Haigh et al 2012b ). This corresponded to an increase in invertebrates in this habitat (Haigh et al 2012a ). At this time, they devoted the majority (66 % ) of their activity to foraging ( Figures 6C and 7).…”

“…They often started their night in the garden and made exploratory trips into the adjacent arable land later in the night, before moving into the arable field completely in September and October of 2008 and 2009. The hedgehog ' s move onto the arable land in September/October in both years coincided not only with an increase in the density of surface invertebrates (Haigh et al 2012a ) but also to the increased amount of time hedgehogs spent foraging (26 % in May 2009to 66 % in September 2009). The high level of activity of the hedgehogs on the arable land was particularly unexpected.…”

“…This corresponded with a peak in mating behaviour in both years, with individuals spending between 11 % (April 2009) and 35 % (May 2010) of their time engaged in courtship during this period. Prey was low in the pasture in comparison to the adjacent arable land (Haigh et al 2012a ) and after the breeding season, hedgehogs moved out of pasture. Similarly, Doncaster (1994) found that hedgehogs showed seasonal variations in dispersal between fields, which he attributed to the use of certain areas during the breeding season and the distribution of earthworm prey.…”

“…The arable field in the present study was surrounded by a mosaic of pasture and gardens and had a well-developed hedgerow network, with good ground cover and a boundary strip. These factors appear to have had a positive impact on the density of surface invertebrates (Haigh et al 2012a ) and, subsequently, on the hedgehogs who feed on them. …”

“…According to Crawford -Sidebotham (1972) , an increase of 2 ° C in temperature at 90 % to 100 % in relative humidity causes a marked increase in the expected numbers of active slugs, which are more than doubled in many cases. In light of the effects of even small changes in temperature, it is not surprising that a drop in temperature from 9 ° C to -1 ° C on October 29, 2008 resulted in a disappearance in potential prey (Haigh et al 2012a ), which coincided with the movement of hedgehogs out of the arable field and the onset of hibernation.…”