Hof et al (2009) hedgehog value urban green spaces
Title: The value of green-spaces in built-up areas for western hedgehogs, Lutra 52; 69-82. 2009
Authors: A. R. Hof & P. W. Bright
Background to study
A UK wide study using data collected from the Mammal Trust UK ‘Living with Mammals’ survey, to investigate the influence of landscape characteristics on the relative abundance of hedgehogs, foxes and badgers.
- Records of hedgehogs, red foxes and badgers and information on location, habitat type, size and description of site, boundary and surrounding area was obtained between 2003 and 2006 from the Mammal Trust UK ‘Living with Mammals’ public participation survey.
- An index of relative abundance was calculated as the total number of records per species per site over the 13 week survey period divided by the ‘total effective recorder effort’ which accounted for the probability of sightings during dawn, day, dusk and night and the approximate observation length as effort.
- Factors including region, urban type (‘built up areas in countryside’ = <50% built up and ‘urban areas’ =>50% built up), surrounding landscape characteristics (area occupied by grass, shrubs, trees, concrete, sheds and wild areas) and landscape type (arable dominated lowlands, pasture dominated lowlands, uplands, lowlands in Scotland, true uplands of Scotland, marginal uplands and islands of Scotland) were investigated to explain variation in the relative abundance of species.
- Of 1711 sites surveyed, 9% were occupied by badgers, 48% by red fox and 30% by hedgehogs.
- Significant differences between the relative abundance of all three species were found between regions:
- Hedgehogs were relatively more abundant in eastern regions of England and in West Midlands (>75 hedgehog sightings/day)
- Badgers were relatively more abundant in south-western regions of England and Scotland (>20 badger sightings/day)
- Red Foxes were relatively most abundant in Greater London and in the south east of England (>75 fox sightings/day).
- The average relative abundance for red foxes was significantly lower in built-up areas in the countryside than in urban areas, whilst more hedgehogs and badgers were found in built-up areas in the countryside.
- Hedgehog presence was positively associated with gardens within pasture-dominated and arable dominated lowlands of England and Wales as well as the presence of a large amount of shrubs and/or pond/lake within or surrounding the site and the presence of a feeder at the site.
- Hedgehog nest box, feeders on site, high grass cover, gaps in boundary and a common, woodland or park in surrounding area positively influenced hedgehog presence in pasture-dominated lowlands.
- Within pasture-dominated lowlands hedgehogs were less often seen in gardens surrounded by arable, in high density urban areas, where dogs and/or badgers frequented the site and if a river dissected the site.
- The presence of badgers and dogs had a significant negative effect on the presence of hedgehogs in survey sites located in built up areas in the countryside, but not in urban areas, whilst the presence of Red Fox was not significantly related to the presence of hedgehogs.
- When all potential hedgehog predators frequented the site there was a larger significant negative impact on the presence of hedgehogs than when just accounting for the sole presence badgers and dogs.
Key messages to landowners and managers derived from these results
- Engaging members of the public to create/enhance features such as shrubberies, lawn and ponds in their gardens and by creating gaps in boundary features will increase the suitability and accessibility of these areas for hedgehogs.
- Creating features such as grassland strips and hedgerows through high density urban areas and arable land may increase the permeability of these land use types for hedgehogs, reducing fragmentation of populations and increasing their distribution.
- Creating/maintain green space areas and strips within new/existing urban and rural areas is encouraged to provide favourable habitat and dispersal corridors for hedgehogs, connectivity and to provide potential refuge from badgers.