Case Study: Hedgehogs

During the past century, hedgehogs have suffered from dramatic declines in population numbers. Current estimations of hedgehog population numbers from the wildlife conservation unit at Oxford University stand at 1.5 million, a figure that was around 30 million in the 1950s. 

Source: http://www.telegraph.co.uk/news/uknews/8696170/Hedgehogs-may-become-extinct-within-15-years.html

REASONS FOR DECLINE

RURAL POPULATIONS

Millward (2011) and O’Connell (2007) list the ways in which the rural hedgehog

population has been hampered by life in the modern anthropocene:

• Changes to farming methods and increases in relative proportion of arable land are reducing the areas available for hedgehogs to live.
• Extensive use of pesticides has resulted in removal of many components of the hedgehog diet.
• Although the exact influence on hedgehogs is unclear, but University of Bristol researchers speculate rodenticides may invoke subtle changes in reproductivity or resilience during fights because of limited blood clotting ability.
• Expansion of urban areas, and thus, reductions in natural habitat area.
• Hedgehogs, and predatory badgers being forced to share habitats.
• 50,000 hedgehogs are run over annually by motorists.
•  Hedgehog migration into urban areas, where they are threatened by strimming, mowing, and being caught in netting.

HEDGEHOGS IN URBAN AREAS

Surprisingly, urban hedgehog populations are thriving more than those in rural areas. Tough even in towns and cities, the picture is bleak, and populations have declined by a third in the past 15 years.

Changing human habits are contributing to the demise of the species. Townspeople no longer leave food out for these nocturnal creatures, and the wild, overgrown gardens that were once a hedgehog haven are now small and neatly kempt.

HIBERNATION

Climatic changes and less seasonal predictability are confusing for hedgehogs. Research has shown that they are often hibernating in January, rather than November. This means that energetic expenditure is higher, and hedgehogs are not in an optimal state at the onset of hibernation. This problem is likely to affect other hibernating creatures, for which, hot summers and cold winters are ideal. Due to climate change, seasons have become unclear, and winters tend to be warmer.

TRANSLOCATION

There is a small glimmer of hope, however. Although it seems unlikely that hedgehog numbers in mainland Britain will recover, the island of Uist in the Hebrides is overrun with them. The generalist nature of hedgehogs, and ability to find new territory with relative ease, makes them ideal for translocation, and this may go some way towards maintaining species numbers.

 References

Millward D. (2011) ‘Hedgehogs may become extinct within 15 years’, [www], available from: http://www.telegraph.co.uk/news/uknews/8696170/Hedgehogs-may-become-extinct-within-15-years.html (2nd January 2012).

O’Connell S. (2007) ‘Hedgehogs: Over the hedge’, [www] available from: http://www.independent.co.uk/environment/nature/hedgehogs-over-the-hedge-399493.html, (2^nd January 2012).

Taylor C. (2011) ‘Help save the hedgehogs this autumn’, [www] available from http://www.guardian.co.uk/commentisfree/2011/sep/27/hedgehogs-autumn-population (2nd January 2012).