I have never seen a Harvest Mouse in the wild and my image of them is of a tiny mouse, clinging to an ear of wheat or in a natural grass meadow. Today, I met up with the Staffordshire Mammal Society, for a Christmas walk (to a pub for lunch of course!) and had my first chance to see evidence of Harvest mice! Our walk was along the Sow valley near Shugborough Hall. At our start walking point, Derek Crawley (the ‘guru’ of British Mammals!) asked me if I had ever seen a harvest mouse nest…. I had not. He guided me down a bank where there was messy line of overgrown grass… there, tucked inside, was a beautifully woven, minute nest!!! I was delighted! It was absolutely tiny, cleverly woven and Derek explained this would have a been a day nest… occupied during the day as a refuge.
Whereas my image of harvest mice in arable fields might have been true some years ago, the truth is that you would be now more likely to find these tiny mice in a reedbed or a clump of cocksfoot grass in an arable field margin.
The harvest mouse is the smallest rodent in Europe, weighing an average of only 5-8g which is about the same as a 2 pence piece. Its blunt nose, small hairy ears and small size distinguishes it from other British species of mice, as does its rather russet-orange fur and white underside. Adapted to climb, it has a very light skeleton and a prehensile tail which can be wrapped around plant stems to keep the mouse from falling.
Harvest mice can have two or three litters a year between late May and October and even into December if the weather is mild – although most litters are born in August and early September. There are usually around six young which are born in the carefully woven grass nests built fresh for each litter. The young are born blind and hairless but grow extremely quickly and soon start to explore outside the nest.
Harvest mice are renowned for making nests which are woven from living plants such as grasses and reeds. The mice split the leaves down the veins to keep the strength in them and use their paws to make the intricate nest in just one or two nights. They can be found quite near ground in tussocky grass, or higher up in taller vegetation such as reeds. harvest mice are the only mice to build nests like this and it is the best way to prove they are around as they are extremely difficult to see.
Derek explained that the tussocky grass and reed beds around the canal and the River Sow were perfect for them. We stopped at several points on our walk, to have a look for some. There were some experienced mammal experts in this group and they soon located a number of these stunning little works of art! I was astounded… the habitat was just not what I would have expected for these tiny acrobatic mice!
This image shows some reeds , upright, with the strands close together… the nests are amazingly difficult to see and it takes an experienced eye…
This breeding nest (bigger and more densely woven than a day nest) was hidden about half way up in the centre of the image….
We discovered a couple more on our walk, each carefully attached to the surrounding reeds and beautifully woven…
Our walk turned up evidence of other mammals too… the reedy, tussocky grass flood meadows were full of vole holes and perfect hunting grounds for Barn owls!
The edge of the river and canal, particularly under bridges showed that otters are also present in the area… sprint, food remains and even some footprints!
A spot of sunshine, lovely walk, harvest mice nests, a pub meal and otter sprint… what more could you want on a Sunday!!