Climate change threatening rare bat species: study

An endangered bat species with a UK population of less than 1,000 could be further threatened by the effects of global warming, a study has found.
Scientists led by the University of Southampton warn that while conditions in the UK could actually become more favourable for the grey long-eared bat (Plecotus austriacus), populations in southern Europe that hold the key for the survival of the species as a whole could be devastated.
The study, published in the journal Molecular Ecology Resources, focused on the grey long-eared bat and showed that its populations in Spain and Portugal are particularly at risk as conditions there become too harsh.

This is of great concern to ecologists because the populations in these areas include pockets with the highest levels of genetic diversity, thanks to their ancestors having survived major climate change events such as ice ages.
This makes them better suited to the hotter, drier conditions associated with climate change, researchers said.
However, other populations in the region that lack such genetic diversity and are unable to adapt to the harsher conditions could become isolated if they cannot fly to more climatically suitable areas because the landscape in between is unsuitable, they said.

This could also stop the bats from better-adapted populations - whose genes could help the threatened bat populations survive - from reaching them.

"As climate change progresses and the environment becomes less suitable for the bats, they will not only struggle to survive where they are currently found but they will also find it more difficult to shift their range to climatically suitable areas," said Orly Razgour from the University of Southampton.
"This reduced connectivity between populations will in turn affect the ability to adapt to changing climatic conditions because of reduced movement of individuals that are better adapted to warmer and drier conditions into the population," Razgour said.
Razgour and her colleagues have developed a new framework to identify wildlife populations threatened by climate change.

It uses ecological modelling and climate data to looking at where climate change is likely to be most extreme; gathers genomic data to assess which species are likely to be most sensitive to the effects of future climate change and considers range shift potential - the ability of a species to move from an unsuitable to a suitable area.
Using these three measures, levels of risk are generated for each population - low risk, medium, medium-high and high risk, researchers said.