Longest mammal field study by an individual
Roger Ransome
65 year(s)
United Kingdom ()

In winter 1956, Dr Roger Ransome (UK) began his study of greater horseshoe bats (Rhinolophus ferrumequinum) in Gloucestershire, UK. He designed and organized annual field research of this species continuously for more than 65 years as of May 2022. His study involves over 14,000 ringed bats. Although data are his, he has willingly shared them in numerous collaborations over this period, to further scientific progress.

Dr Ransome first conducted studies of greater horseshoe bats in the mid-1950s while a student at Cheltenham Grammar School for Boys, aged 16 years.

Initially his project involved ringing hibernating bats roosting in abandoned mines near the town of Nailsworth. From 1959, his summer research began at Woodchester Mansion, a Victorian Gothic building located near Nailsworth. The attics of this unfinished house host maternity roosts of greater horseshoe bats (among other bat species) each summer (May–September) and hibernating ones use its cellars or tunnels in winter. The site has proved to be invaluable for chiropterologists.

Over decades, his wealth of data about greater horseshoe bats ranged from hibernation, reproduction success, pup growth and population control. These led to many discoveries about their physiology and behaviour. Recognized as one of the world’s foremost bat experts, he has published more than 50 scientific papers, two books and contributed to many more publications, conferences and studies/projects.

Image credit: Ian Unsworth