Mini mammals are a group of mammals that are under recorded across Britain, these include the mice; house mouse, harvest mouse, yellow-necked mouse and wood mouse. The shrews; common shrew, pygmy shrew; water shrew, lesser white-toothed shrew, greater white-toothed shrew and Millet’s shrew. The voles; bank vole, field vole and Orkney & Guernsey vole.
To help increase our knowledge of the distribution of mini mammals The Mammal Society started a national survey to get everyone involved in their local area. As mini mammals had not been surveyed at Gibside before I decided to get the ball rolling and start the annual survey.
Myself, Veronica Carnell (a local mammal expert) and Catherine Robson (one of our volunteers who has recently completed her Master disertation on water shrew populations) chose two sites within the grounds, the quarry site and ladyhaugh meadow. 10 longworth traps where set up in each site in a line 1m apart. Bait and hay were put in each trap and left locked open for 24 hrs so that the mammals got used to them. We used sunflower seeds, pieces of apple and casters for bait. Casters are the next stage in the life cycle of a maggot. They are the chrysalis of a maggot, a shell-like pupae that contains the soon-to-emerge fly.
The following evening we replenished the bait and hay then set the traps to lock when the treadle inside the trap was touched. 7am the following morning we came back to see what we had caught. If the door to the trap was shut we carefully put the trap inside a big plastic bag to open them, this was just to stop the mammal from jumping out and getting hurt. The traps were opened and the contents carefully emptied out into the bag so we could see what we had caught.
At the quarry site we caught 4 bank voles and 2 wood mice and at ladyhaugh meadow we caught 3 wood mice and a common shrew. This data has been sent to The Mammal Society and will contribute to their national survey to plot the distribution of mini mammals. The data will also contribute to our own site records and as we repeat the survey each year we too will get a better picture of our mini mammals at Gibside.