Going GREENER

HOW HAS YOUR WORK HELPED THEM?

All bats and their roosts are protected by law. Horseshoe bat foraging habits are also protected. My diet and growth studies show how to improve habitats and that a small heater put into the maternity roost boosts populations.

AND YOU’RE A RECORD-BREAKER?

Yes, I’m in Guinness World Records for the longest-running field study of a single mammal by an individual. I started this survey in 1956, making it 65 years.

SOUNDS LIKE A LOT OF WORK…

It is, but I get a lot of practical help with surveys and counts from many volunteers. Over the summer, we do a bat count every Sunday and collect bat droppings to see what they’re eating. I ring the babies, too, to see their growth. It is hard work, but it’s worth it.

HOBBY OR DAY JOB?

Both. I taught science for 33 years, then worked as an environmental consultant and have funded most of my studies myself. Since 1990, I have been an Honorary Research Fellow at Bristol University. I’ve written more than 50 scientific papers on bats, as well as two books. I’m now retired, but I don’t plan on stopping any time soon.

WHAT’S CHANGED OVER THE YEARS?

The habitat conditions in Woodchester Valley, where I do the survey, have changed dramatically. When I started, it was surrounded by grazed fields and mature beech trees, and 100 babies were born a year. In the 1960s, lots of deciduous trees were cut down and replaced by conifers. We also had some very cold winters. Both devastated food supplies and the population crashed. It took ages to recover. By 2011, with milder weather, the number of births hit 92.

GREATEST DISCOVERY?

The impact of temperature upon hibernating bats. I manipulated conditions in the Woodchester cellars with heaters, as I believed a specific temperature affected how often bats woke up. They allow their body temperatures to fall to the exact external conditions. I found they woke up every day at 10°C, but once in 12 days at 7°C. This particular reaction to temperature is unusual in mammals.

WHY KEEP GOING?

The longer any ecological research continues, the more useful it is. I’m now working with five universities on a Dna-sequencing study. I’m always making discoveries. I wouldn’t carry on otherwise.