Harvest Mouse Nest Survey

Today I joined staff and trainees from YWT and RSPB on a harvest mouse survey at a relative new site at Adwick Washlands in South Yorkshire.

The Harvest Mouse (Micromys minutus) is increasing rare in the UK.

They are one of our smallest mammals, at just 5-7cm long, and have a gingery coat with a paler belly.   They prefer to live in long tussocky grassland, reedbeds, hedgerows and around woodland edges.

They build a spherical nest of tightly woven grass, high up amongst the tall grasses. For this reason, they prefer grasses with a wide leaf, rather than harder, spherical stems found on many reeds.

As harvest mice are very small and timid, the best way to survey is to look for distinctive nests. These are grass balls, between the size of a golf and a tennis ball, found between knee and waist height.  The ten members of our group surveyed several fields, walking slowly in a line to search the grasses for nests.

We found two nests, both in quite poor condition (nests are normally abandoned over winter). The best time to carry out survey is in early winter months, before heavy snow and strong winds have destroyed the nests. 

We also saw several small scurrying creatures (probably field voles) that were a little too fast to positively identify.  Within the areas of larger reeds, we also found several latrines and burrows.

We also saw hare, a kestrel, and english partridge on the site.

More information on harvest mice can be found on the Mammal Society website.

 RSPB Adwick Washlands