National Mammal Week 2021 Blog Series - Tuesday 26 October
A Scottish Search for Harvest Mice
Derek Crawley
Derek is a valued and active member of the Mammal Society he has also previously sat on the Society's Council. Derek is Chair of the Staffordshire Mammal Group and a Regional Coordinator for the National Harvest Mouse Survey. As part of the survey, Derek packed his cold weather gear and headed north to look for harvest mice in Scotland.
I have been looking for harvest mice in Scotland ever since I started working on the Mammal Atlas, as having found them in the north of England, both on the east and west close to the Scottish borders, I am convinced they are just under recorded there. When looking at the records there were a few in Scotland both from the 1993 atlas and since 2000. The now president of the Mammal Society Penny Lewns also recorded a harvest mouse nest in 2015 on the north coast of Scotland. Therefore I thought there must be others and when the Society decided to run the National Harvest Mouse Survey I wanted to carry out some surveys in Scotland! NatureScot were interested in looking at the status of this rare species so this provided me with some funding for a week long survey of the historic recorded sites for harvest mice. After a lot of planning I worked out a route to drive 1650 miles and get in at least 20 site visits covering a range of both verified and unconfirmed sites.
I set off early from Shropshire to arrive at Ken-Dee RSPB Reserve at 10am where harvest mice had been seen by an old warden back in the the late 1990s. I was able to get permission to drive down the track and carry out my surveys in front of empty hides on the loch edge. Thankfully, no biting insects so far! No harvest mouse nests either, but I did record field voles, moles and roe and red deer. Just off the reserve I stopped at a likely looking reed bed and spent over half an hour hidden away in over 6 foot tall phragmites and red canary grass. No nests. The afternoon and early evening saw me near Newton Stewart on the Cree marshes, still no harvest mice but it was good to see that there was some brilliant habitat for them.
Day 2 and I travelled north to Ayrshire and Glasgow. The Don valley has floodplains of Reed carmel grass and although I've searched without success before, it was worth an hour looking again, although still luck. Next I headed to Hunterston power station where a dead harvest mouse was recorded in 2021. Still no luck but I wasn't disheartened yet!
That night in a hotel halfway between Glasgow and Edinburgh I reflected on the fact I had just last month found a new site for harvest mice at Strathclyde Country park, so I was looking forward to finding other nests this week... The morning brought heavy rain on the drive to my first site near two old records on the Moreton Hall estate south of Edinburgh. The weather cleared up when I met with George Hogg on site, who recorded the dead mouse at Hunterston. We discussed species recording, especially harvest mice, and he suggested some additional sites to try.
I moved on to the Loch Leven RSPB site where one of their volunteers took me to the location of their 1990s records, the land use had changed and it is now a lagoon but there was good rough grass habitat nearby and I wish I could have spent more time here but I still needed to travel up to Aberdeen. No sign of the harvest mice I was looking for, but a field with 9 roe deer were seen at Loch Leven.
Arriving in Aberdeen before it got dark I decided to try to see some bottle nosed dolphins at the harbour entrance, no success there but I did do another nest search in the cocksfoot grassland. In August 2020 Carol Richardson found a harvest mouse nest on the Scotstown Moor area of grassland on the outskirts of Aberdeen. I had arranged to meet her and some students from Scotland's Rural College, SRUC, along with their lecturer Nick Littlewood the local mammal verifier. Having 20 people carry our a survey should increase your chances of finding nests but not in this case sadly, even with nearly two hours of intensive searching.
On my firth day of surveying with no evidence found I was hoping that the site at Betty Hill on the North coast would be positive as it was for Penny back in 2015. The woodrush and moor grass habitat was excellent but no nest was found. It was then the start of the long drive home. Despite not finding any nests on this occasion, I do believe that harvest mice are still present in low densities in Scotland - they are just much harder to find than those elsewhere in the UK!
Was my confidence in finding nestles dented? Yes it was, but then having restarted lead training in nest searches in Stafford, it took me just 5 minutes to find and display a nest to the group of 12. We all searched the same reed bed and although 15 nests were found some people never found a nest showing that group surveys are better then single surveyors so maybe my next survey of Scotland a need more volunteers to help.
To find out more about what's going on during National Mammal Week 2021 click here.
