University detects rare bat species at Sutton Hoo

A citizen science partnership in Woodbridge which has expanded to cover Sutton Hoo has reported a thriving bat population at the National Trust site – including detections of one of the UK’s rarest bat species.

Transition Woodbridge, a community-led collective which works to achieve positive sustainable action in the town, has worked with researchers and students from the University of Suffolk’s Wildlife, Ecology and Conservation Science course for a number of years to monitor bat populations in the town.

The group installed monitors at Sutton Hoo for two seasons at the end of summer and early autumn, with latest data from the University reporting hundreds of nightly bat movements across nine-to-ten different species.

Among those is the barbastelle bat, a species which the Bat Conservation Trust considers to be rare in the UK, and only found in southern and central parts of England and Wales.

The common pipistrelle was the most prominent species, with some parts of the site recording up to 900 movements per night.

Dr Mark Bowler, Course Leader in Wildlife, Ecology and Conservation Science at the University of Suffolk who oversees the data analysis, said: “To most people Sutton Hoo is the burial site of an Anglo-Saxon ship but it’s also fantastic for bats and is brilliantly managed for nurturing wildlife.

“Bat numbers are in decline but Sutton Hoo’s bat population is doing really well.
“With Martlesham Wilds and Foxburrow Nature Reserve nearby, it makes a natural triangle with Woodbridge in the middle, so bats move between the reserves through people’s gardens.”

On the barbastelle bat, Dr Bowler added: “Suffolk and Norfolk are really the stronghold for the rare barbastelle bat. They are low in density which makes them hard to find, but we find them regularly at Sutton Hoo so it’s a great conservation good-news story in our county.”

The partnership first started collecting data in 2022 and utilises audio devices attached to wooden poles which detect movements. The recordings are then collected and analysed by computer algorithms to determine the species. Students at the University of Suffolk spent hours verifying the results manually to confirm the species.

Eighty audio devices are placed in gardens by volunteers from Transition Woodbridge for around two weeks at a time, rotated between gardens to provide an even spread through the year.

Sixteen of those detectors were then placed at Sutton Hoo for the last two years for a two-week period at the end of summer and into September.

Jane Healey, Co-ordinator of the Transition Woodbridge team, said: “We’re loving collaborating with Mark and his team at the University of Suffolk, and with Sutton Hoo to get these amazing results.

“People want to help do something positive for nature, and what’s easier than hosting a post in your garden to monitor an indicator species in your very own town? Discovering we have so many species is the icing on the cake! 

“It also underlines everyone’s efforts to encourage the habitats, plants and insects that bats like.”

Matt Wilson, Countryside Manager for the National Trust’s Suffolk and Essex portfolio, said: “The survey results are even better than we thought they might be, with audio from nine-to-ten of the UK’s 18 species recorded. It’s great to know that both common and rarer bat species, like the barbastelle, are thriving here at Sutton Hoo.

“We know the combination of open habitats, some of our buildings, the woodlands and both fresh and estuary waters offer great feeding and movement corridors for all sorts of species. Practical conservation work by our rangers and volunteers, such as woodland coppicing, maintaining acid grasslands and managing scrub, provides the variety of plant – and, in turn, insect species – that different bat species need to feed on.”

Morgan Robbins is a final year Wildlife, Ecology and Conservation Science student who has analysed the recordings and sonograms to identify the bat species for her dissertation.

Morgan, from Bildeston, said: “I went around Sutton Hoo lots as a kid and looked at all the old artefacts, which was really cool, but now doing this you see that the area itself is so interesting with such an abundance of rich British wildlife too.

“I really enjoy the data analysis side, and using this experience with a real-life project, it feels great to know I am helping in some way, and it’s great experience as I am now applying for jobs.”

The partnership is also expanding its work with schools, including primary schools in Woodbridge, for which the collaborative group has secured funding from East Suffolk Council on behalf of the Greenprint Forum to install bat boxes to further improve their grounds for bats.

Dr Bowler is also keen for sixth forms and colleges to get involved in the project to survey bats on school grounds and promote an interest in ecology.

For those in the area who are keen to support bat species, homeowners can encourage bats to visit their gardens by installing ponds, or planting trees – particularly native species – as well as plants which attract insects.

To find out more about Transition Woodbridge, visit the website here.

For more information on Sutton Hoo, visit the National Trust website here.

More details about the University of Suffolk’s BSc (Hons) Wildlife, Ecology and Conservation Science degree can be found on the website here.