Zsalako (2012) Hedgehog ecological review Gaywood River Valley
Title: Assessment of the ecological network in the Gaywood River Valley: Landscape connectivity case study of the European hedgehog (Erinaceus europaeus), Masters Dissertation, University of East Anglia UK. 2012
Authors: D. Zsalakó
Background to study
An investigation into the movement costs for hedgehogs traversing a river valley corridor using Geographical Information System (GIS) analyses.
- Land use types (habitats) and features (roads, rivers etc) within the Gaywood River Valley catchment were mapped using ArcGIS and assigned resistance values based on a priori information of their permeability to hedgehog movement.
- Of 16 land use types and features, grasslands, deciduous woodlands, village/farms and hedgerows were assigned lower resistance values, given their preference by hedgehogs and the remaining land use types, including arable land, heathland and conifer woodlands were assigned higher resistance values which reflected the matrix of suboptimal and unsuitable habitats within the study area.
- No absolute barriers to hedgehog movement were identified however roads and the Gaywood River were assigned higher resistance values due to the associated risks of mortality.
- Areas within 270 m of an active badger sett were assigned high resistance values as previous research has identified that hedgehog distribution is confined by the presence of badgers.
- Records of hedgehogs spanning 14 years and with an accuracy of <100 m were used as a source layer within the GIS modelling environment to evaluate the accumulative cost for each cell to return to the closest hedgehog record.
- Analysis revealed that the western areas which were primarily urban and the central region of the study area had the largest continuous sections of ‘movement-friendly’ landscape whilst the agricultural landscapes to the east of the study area were more impermeable.
- Roads divided the permeable landscapes into blocks and badger presence in the central area resulted in a large areas deemed unsuitable to hedgehog movement.
- Despite the presence of hedgerows and small patches of suitable habitat, arable landscapes were identified as the least permeable to the movement of hedgehogs.
Key messages to landowners and managers derived from these results
- Least-cost path analysis is a useful and recommended tool that can help to inform on areas where conservation efforts should be focussed to improve suitability and dispersal success for focal species.
- Maintaining and/or restoring hedgerows within arable farmland are recommended to encourage dispersal of hedgehogs across the landscape and prevent the isolation of populations.
- Entry into stewardship schemes and woodland grants that compensate for increasing the patch size of woodlands and that help towards establishing/maintaining grassy margins and hedgerows is recommended as these measures can help to increase the suitability of these areas for hedgehogs.