A Tale of Two Mice (and other monitoring projects)

The philosophy for the management of our 40 acre site at Denmark Farm has always been minimal intervention, and a holistic approach. This means that rather than managing the land for a particular species, we encourage a diverse mosaic of habitats – including woodland, marshland, grassland and ponds – and then sit back and see what turns up! To identify some of the species which choose to breed, feed or shelter here we have a number of wildlife monitoring programmes. This year we have also invited specialist groups to site including the ‘Mammals in a Sustainable Environment’ (MISE) project, and the Amphibian and Reptile Conservation Trust and they have applied their expert knowledge and monitoring techniques to find out more about the species using Denmark Farm.

Earlier this year we installed 50 dormouse boxes around the woodland and shelterbelts:


Dormouse box at Denmark Farm

This is something we’ve been planning to do since the exciting find of a ‘nibbled’ nut on one of our mammal courses. Dormice open hazel nuts in a very distinctive manner, and finding a characteristic  nibbled nut is a good indication that they may be using a woodland. Dormice are found infrequently in Ceredigion, and a nibbled nut can generate huge excitement – as this one did (read the BBC news article here).

The dormouse boxes have been checked regularly through the summer. Each time, there is a sense of anticipation at the prospect of finding a dormouse…


…but so far we haven’t been lucky! But with our ‘holistic’ approach in mind, we have been pleased to find that wood mice have taken up residence in some of the boxes. A few of the boxes have also been used by nesting birds – not a problem, as dormice often don’t use the boxes until early autumn by which time the birds have vacated the box (there’s no point in having a property standing empty!)

We are currently also using bait pots to monitor for harvest mice with the MISE project. If these tiny mammals are present they will climb up the vegetation, pop in for a mealworm or two, and leave droppings (a wire mesh excludes any mammals larger than pygmy shrew and harvest mouse).  When the pots are collected a week or two later, any droppings are sent for DNA testing at the Waterford Institute of Technology, and the species can be identified. Clever stuff!


Jenny MacPherson (MISE project) preparing harvest mice bait pots at Denmark Farm

Harvest mice are the only mammal which make a woven nest above ground in the ‘stalk layer’ of dense vegetation such as grass or reeds; searching for their nests in November and December is another way to identify if harvest mice are present:


Harvest mouse nest

The Mammal Society are currently looking for volunteers to search for harvest mice nests across the UK. There are very few records harvest mice records in Wales, so please do let us (or MISE project) know if you’ve seen a harvest mouse, or it’s nest!

Harvest mouse

Harvest mouse (Micromys minutus)

Our own volunteers and supporters often get involved with these wildlife monitoring activities, which cater for a range of interests and experience, and include anything from the Big Butterfly Count to ornithological surveys. Denmark Farm provides an ideal location to identify and study a variety of species, and our conservation courses also generate useful data about species, from bats to invertebrates to higher plants. Why not come along to our volunteer day on 23rd November to learn more about the reserve and its wildlife?

You can also support our work in other ways, such as becoming a member.

Recording any species found is also an important part of monitoring. Your Local Records Centre is always keen to receive records, no matter how common or widespread (ours is the West Wales Biodiversity Information Centre) .  If you are unsure of your identification, your Local Records Centre can also help to put you in touch with a local expert, or you could try using iSpot to get an identification from an on-line community of knowledgeable people. These records are a valuable source of information for decision-making at all levels, and their use helps to protect and improve biodiversity.

Now where did I put that notebook….


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