Press release 2014/09 - Issued by the Centre for Ecology & Hydrology, UK -

***Strictly embargoed until 1901 GMT London time on Thursday 30 October 2014 ***

New research has shown that despite moving house frequently, bats choose to roost with the same social groups of ‘friends’.

The study, published today in the scientific journal PLOS ONE, found that different social groups roost in separate, though adjacent, parts of woodland. The findings have important implications for conservation as bats may not be able to move to another area if a section of woodland is felled. The research was carried out by scientists from the Centre for Ecology & Hydrology, the University of Exeter and the University of Oxford.

The research team concluded that the structure of bat social groups differs between two different but closely-related species living in the same woodland. One species Natterer’s bat (Myotis nattereri) forms mixed-sex social groups while a second species, the Daubenton’s bat (Myotis daubentonii), has largely separate male and female groups.

Dr Tom August from the Centre for Ecology & Hydrology, who conducted the study, said, “When the first results came through it was a real eureka moment, I hadn’t expected to see so many separate social groups in the woodland.”

The study was carried out over a five year period in Wytham Woods, Oxfordshire in the UK. Nearly 1500 bats were fitted with small aluminium arm bands and four bats were tagged with tiny lightweight radio-transmitters to enable them to be tracked. The radio tracking showed that the bats changed roost site frequently - about once every two days.

Dr Fiona Mathews from the University of Exeter who led the research team said, “This work has really important practical implications for bat conservation. We now realise that although social groups of woodland bats ‘move house’ every few days, they remain within a very small geographical range. This means that even quite small-scale tree felling may destroy all the roosts potentially available to a group.”

Each social group was found to occupy a home patch in the wood. Although the two bat species occupied the same area of woodland, the home patches of the different social groups within the species did not overlap suggesting that social groups may defend their roost areas. The relationships between bats in the same social groups were found to be enduring, in many cases lasting more than a year.

Tom August added, “Learning about bats’ social structure helps us understand how best to protect populations in the wild, but this study is only the beginning, we still have a lot to learn.”

Co-author Danielle Linton from the University of Oxford said, "The patterns of social organisation that have emerged from seemingly random ring recapture data are fascinating. Using the same sampling regime striking behavioural differences have been revealed between two similar species that roost in the same area."

Dr Fiona Mathews said, “The social networks of animals are poorly understood. Yet they are fundamentally important to processes ranging from information transfer to the spread of disease. Just as some types of people are super-connected on Facebook, this work shows that in animal systems, two very closely related species living in the same habitat can have very different kinds of social network.”

Contact details

For more information please contact the CEH Press Office.

Additional information

Paper reference: Tom A August, Miles A Nunn, Amy G Fensome, Danielle M Linton, Fiona Mathews (2014) Sympatric woodland Myotis bats form tight-knit social groups with exclusive roost home ranges. PLOS ONE. doi: 10.1371/journal.pone.0112225. Publication date 30 October 2014 1900 GMT. PLOS ONE is an open access (free) journal.

This work was supported by NERC grant no NE/G523571/.

The Centre for Ecology & Hydrology (CEH) is the UK's Centre of Excellence for integrated research in the land and freshwater ecosystems and their interaction with the atmosphere. CEH is part of the Natural Environment Research Council (NERC), employs more than 450 people at four major sites in England, Scotland and Wales, hosts over 150 PhD students, and has an overall budget of about £35m. CEH tackles complex environmental challenges to deliver practicable solutions so that future generations can benefit from a rich and healthy environment. You can follow the latest developments in CEH research via Twitter and our RSS news feed.

NERC is the UK's main agency for funding and managing world-class research, training and knowledge exchange in the environmental sciences. It coordinates some of the world's most exciting research projects, tackling major issues such as climate change, food security, environmental influences on human health, the genetic make-up of life on earth, and much more. NERC receives around £300m a year from the government's science budget, which it uses to fund research and training in universities and its own research centres.

The University of Exeter is a Russell Group university and in the top one percent of institutions globally. It combines world-class research with very high levels of student satisfaction. Exeter has over 19,000 students and is ranked 7th in The Times and The Sunday Times Good University Guide league table, 10th in The Complete University Guide and 12th in the Guardian University Guide 2014. In the 2008 Research Assessment Exercise (RAE) 90% of the University’s research was rated as being at internationally recognised levels and 16 of its 31 subjects are ranked in the top 10, with 27 subjects ranked in the top 20. Exeter was The Sunday Times University of the Year 2012-13. The University has invested strategically to deliver more than £350 million worth of new facilities across its campuses in the last few years; including landmark new student services centres - the Forum in Exeter and The Exchange on the Penryn Campus in Cornwall, together with world-class new facilities for Biosciences, the Business School and the Environment and Sustainability Institute. There are plans for another £330 million of investment between now and 2016.

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