National Mammal Week 2021 Blog Series - Monday 25 October
Introducing the National Harvest Mouse Survey!
Frazer Coomber
Frazer is the Mammal Society Science Officer. He joined the Society in February 2018 and is at the heart of the Society's research. He completed his PhD at the University of Genoa where he studied the impact of shipping traffic on Cuvier’s beaked whales in the Mediterranean Sea. Frazer is passionate about all mammals and is interested in the effect of human disturbance on their ecology. He has been working hard to organise the National Harvest Mouse Survey.
The harvest mouse (Micromys minutus) is the UK’s smallest native rodent and it has recently been classified as “Near Threatened” in Great Britain on the IUCN’s red list of endangered species. However, it is difficult to quantify the population and conservation status for this species as records, density estimates and occupancy data for key habitats, along with changes over time (especially population) are limited. This lack of knowledge has meant that past distribution and population trends are uncertain. It is believed, due to changes in agricultural practices and climate change, that the future prospects of this species are poor. It is because of this uncertainty that the Mammal Society has committed to push for another national survey. The survey is hoped to provide robust scientific evidence, with the help of volunteer surveyors, that can be used to gain insights into the distribution, population and conservation status of this species.
This September has already seen the beginning of the national survey with various local mammal groups and interested volunteers starting to put on training events and host nest searches - but why should we be doing a survey now? It is recommended that systematic surveys to identify changes in wildlife distributions and populations be conducted every seven to ten years. The last Mammal Society harvest mouse survey took place over 2013 and 2014, 8 years ago, so this year is the perfect time to start a repeat survey. It is also highly fitting because 2021 marks the 250th anniversary of the scientific naming of the harvest mouse! Furthermore, after the discovery of the lack of information on this species during the latest review of mammal conservation in 2018 the collection of this vital information now will provide higher reliability for future reports.
Data and information officer Charlie Le Marquand and I have been working hard behind the scenes to bring together different aspects of the national survey. This has involved creating and producing content for a dedicated survey website (https://www.mammal.org.uk/science-research/harvest-mouse-project/). Here you can find all the relevant information necessary for any aspiring volunteers, documents include a survey protocol, how to search for nests and how to record your surveys, plus training videos and other resources to help identify and find harvest mice nests. An events calendar also exists on this webpage with various training and nest searching events so interested volunteers can find out about and get in touch with coordinators from their local area.
Given the national scope of this survey one of the main things that the Mammal Society team are involved in is the organisation and support of regional local groups, volunteers and coordinators. The driving idea behind this survey is to bring together and promote local mammal groups, many of which will be, or in the past have, surveyed for harvest mice. This has involved contacting groups from across the country to put in place regional coordinators, who can act as points of contact for interested volunteer surveyors and direct them to suitable sites to search for and record harvest mice nests. Their site selection is supported by us through the creation and sharing of baseline maps that can be used to identify previous harvest mouse presences and un-surveyed areas so that new surveys can confirm persistence and increase our understanding of their distribution respectively.
We have made good progress in putting many perspective volunteer surveyors in touch with local coordinators. However, we are still looking for any interested people to act as coordinators as we do not have all counties across the country covered as yet. So if you have experience in harvest mouse nest searches, or are part of a local mammal group interested in being involved we would love to hear from you (surveys@themammalsociety.org).
To find out more about what's going on during National Mammal Week 2021 click here.
