An investigation of factors potentially causing changes in hedgehog (Erinaceus europaeus) numbers in the UK

A completed 3-year PhD study by Claire Dowding
Supervised by Stephen Harris and Phil Baker


The hedgehog (Erinaceus europaeus) is widely distributed in Britain and is one of the most conspicuous and popular British mammals. However anecdotal evidence suggests that hedgehog numbers are rapidly declining in Britain and it appears that this decline may be more extreme in rural areas than urban areas.

There are numerous potential causes of a decline in hedgehog numbers. Predation by badgers (Meles meles) and road mortality has been shown in past studies in rural areas to have a negative impact on hedgehog numbers and this may also be important in urban areas. The intensive use of insecticides in urban gardens and annual changes in weather patterns may affect food availability over the hedgehog's active season. Gaining adequate fat deposition before the onset of winter may therefore become more difficult for hedgehogs and this may result in a higher rate of over-winter mortality. Temperature changes throughout the hibernation period may result in hedgehogs rousing when there is no food available. This would thus use up vital energy reserves, leading to mortality or reduced post-hibernation condition. In this study I will investigate the factors affecting hedgehog population dynamics and behaviour in urban areas since these may represent a refuge habitat for hedgehogs in Britain.

The study site

A site in suburban Bristol has been selected in which to carry out the study due to the growing importance of urban areas to hedgehog populations in the UK. The area encompasses a range of habitats and housing densities and has both hedgehog, fox and badger populations.


The overall aim of the PhD project is to investigate the factors that may be contributing to the perceived decline in hedgehog numbers in the UK.

The following aims will be investigated in greater detail:


Movement and activity behaviour of hedgehogs will be assessed by radio tracking. Information on population dynamics will be gathered by capture-mark recapture of individuals and collection of carcasses. Further work will be carried out in the lab including post-mortems, diet analysis and chemical analysis of organs.

Contact details

Email: Claire Dowding