The examples of flora and fauna that have disappeared due to human excesses over the past 50 years are numerous, but research has found that the decline of a characterful bat in the UK began when its trees were felled for shipbuilding 500 years ago.
Experts of the University of Exeter and the Bat Conservation Trust (BCT) concluded that a 99% decline in Britain’s western barbastelle bat populations began when trees were felled in the early days of Britain’s empire building.
The conclusion was made possible by analysis of bat DNA that can identify a “signature” of the past, including periods when populations declined, leading to more inbreeding and less genetic diversity.
Dr Orly Razgour, a molecular ecologist and conservation biologist at the university, said: “These bats usually roost in mature oak and beech trees and move around every few nights – so they take advantage of areas with significant forest cover.
“Our findings show that northern and southern British populations declined over several centuries, starting around 500 years ago. This coincided with a period of widespread tree felling to provide timber for colonial shipbuilding. It is likely that the decline that we found was caused by this loss of woodland – which has continued since that period.”
The western barbastelle bat‘s distinctive features include large ears that meet in the middle, a flattened face with a pug-like nose, and dark silky fur tipped with white. It is 4 cm to 5 cm long and has a wingspan of about 26 cm. Females give birth in early summer and raise a single young each year.
For the study, the researchers humanely captured and tested western barbastelle bats in 15 British, Spanish and Portuguese forests.
Dr Katherine Boughey, the head of science and monitoring at BCT, said: “This technique is a game changer for bat conservation. Until now, we have only been able to look at recent changes in populations, although anecdotal evidence suggests that British bat populations are at historic lows. Now we have evidence for the historical decline of bats, but we urgently need similar evidence for other bat species.”
The BCT says that the “very rare” species in the UK is only found in a few places in southern and central England and Wales.
to newsletter promotion
The paper detailing the findings is published in the Journal of Applied Ecology.
