Harvest Mouse Research

The Harvest Mouse (Micromys minutus) is the UK’s smallest mammal weighing in at around 7g and exhibiting the only truly prehensile tail which it uses to grasp stalks with whilst living an arboreal existence during the summer months. It is however on the UK BAP list as it is believed that their population numbers have declined.

 

So what is the situation in Oxfordshire? Well very little recording of harvest mice has been done in our county with the vast majority of records actually coming from several small WildCRU (Oxford University) research projects and until we get more records for harvest mice how will we know whether or not this small mammal species is declining?

 

So in light of that, The Oxfordshire Mammal Group organised and ran a Harvest Mouse Nest Training Day at BBOWT’s Chimney Meadows in November 2014. Searching for harvest mouse nests in early winter is the best and easiest method to find these elusive mice. Although the density of nests does not provide a true population estimate because females build a nest for every new litter and males will build nests too, it does provide more information than just a ‘yes’ or ‘no’ to their presence especially when taking into consideration changes in habitat, farm management and breeding success.

 

The training day was very successful with 40 people coming out to learn how to find and then identify harvest mouse nests. In total over 100 nests were located in two field-side margins, this is not a usual haul as the margins were exceptionally wide (25m plus) on this farm!! Here's a lovely review one of the attendees wrote on LinkedIn: http://tinyurl.com/ph37jqo 

 

The aim for the future is to continue running these Harvest Mouse Nest Training Days and get members and volunteers out and about to find nests. If we can determine nest density on an annual basis this may then go some way to help elucidate how well harvest mice are doing at this one particular site in Oxfordshire. Eventually it would be fantastic to get these trained nest finders covering every square kilometre in Oxon to help us produce a 1km  presence/absence distribution map. Now that’s not a tall order, is it?

A poster summarising the initial findings of the project can now be downloaded here.

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© 2019 by The Oxfordshire Mammal Group.