Small mammal survey on agricultural land during conversion and into full organic production

Summary

This report was presented at the UK Organic Research 2002 Conference. Loss of food and suitable habitat due to modern intensive farming and the decline of mixed farming systems has lead to a reduction in numbers of small mammals on farmland in the UK. Organic production systems are believed to encourage biodiversity. Small mammal surveys were carried out on Coswinsawsin Organic Demonstration Farm in November 1999, April and November 2000 and October 2001. 50 Longworth traps were set in pairs at 5 metre intervals along a hedgerow and checked morning and evening for three days. Trapped mammals were identified, weighed and with the exception of shrews, marked by a small fur clip before release. The wood mouse was the most prevalent species trapped. Other species included the bank vole, the field vole and the common shrew. The highest number of shrews was caught during the April survey. No change in population size or species diversity was demonstrated.