Rodents in the Rain
March 5, 2015
Volunteer Rangers in the Hampshire area of the South Downs National Park started the New Year in a watery way with some important wildlife surveys.
A drizzly Monday morning in early January saw us head across to Noar Hill on the Rotherfield Estate to begin our hunt for harvest mice nests.
Following an earlier meeting held by the Selborne Landscape Partnership, we heard that there was only a single recent record of a harvest mouse within a 5km radius of Noar Hill since 1999. Seeing as the harvest mouse was first documented as a new species by Gilbert White in Selborne in 1767, the partnership agreed that this was a huge opportunity to now look for evidence of more. So, in conjunction with members of the Game and Wildlife Conservation Trust, Butterfly Conservation Trust, National Trust, Rotherfield Park, local landowners and South Downs National Park Authority (SDNPA) staff we set about organising a new round of harvest mouse surveys.
Harvest mice are the smallest native mouse and make tennis-ball sized nests from strips of grass during the summer months. They then abandon them over winter when they seek shelter lower down to keep out of the weather. To find their nests you have to look around field edges and hedgerows rummaging for their fine balls of grass. Typically harvest mice like to build their nests around a supporting structure such as a bramble or plant stem so areas of brambles with lots of grass tussocks are ideal. Established field headlands provide such a habitat, which many birds and insects also use for shelter and food. This demonstrates the importance of maintaining a connected, marginal habitat whilst harvest mice make a good edge indicator species.
In our survey we split into two teams to tackle opposite halves of a large field with an excellent looking hedge/margin in the middle. Unfortunately the weather chose this moment to go from drizzle to downpour; but it takes more than a bit of rain to stop the Volunteer Ranger Service! We persisted and in a wet two hours we found 11 nests. This, in combination with a previous training day held at nearby Norton Farm, now puts the total number for harvest mice within the same Selborne area at 55 nests recorded – something of an improvement on the original single record.
With more surveys still to go, things are looking bright for the harvest mouse in Hampshire.