The field vole (Microtus agrestis) is one of the three species of vole found across the United Kingdom. It is the most common species of the three and it plays a vital link in the food chain.
Field voles can be difficult to distinguish from the bank vole as they are very similar in appearance but field voles tend to have darker and longer fur, smaller ears and shorter tails. Voles can be more easily distinguished from mice by their less prominent eyes and ears as well as having blunter noses. Field voles can be very aggressive creatures and the males can be heard squeaking as they fight over their territories.
The field vole is predated on by several species such as kestrels, barn owls, foxes, stoats and snakes. It is thought that between 40-80% of a barn owl’s diet is made up of field voles showing their importance in the ecosystem.
As a vole travels, it marks its runways with urine to warn off other voles, however these urine tracks can radiate ultraviolet light which can be detected by birds of prey, therefore leaving a trial for the birds to trace.
As a rodent, field voles have high reproductive rates; females may have up to 7 litters of between 4 to 6 young a year. Rarely, field voles can reach plague proportions with up to 500 individuals per acre. Despite this, it is thought that the field voles numbers are decreasing and although they are common across the country, their roles in the food chain makes them important species to protect.