Paul Racey has devoted his career to advancing knowledge about things that go squeak in the night.
The Regius professor of natural history, who recently retired from the University of Aberdeen after 36 years at the institution, is an expert on bats. His interest in the nocturnal mammal began while he was an undergraduate studying natural sciences at the University of Cambridge. He recalls that it was his love of the early evening that initially sparked his curiosity.
"Dusk has always been my favourite time of day, when one group of animals goes to bed and another gets up," he said. "I enjoyed being out and walking at dusk because I was able to see all these things flitting around and wanted to learn more about them."
Although his studies have led to many breakthroughs in our understanding of bats, Professor Racey said he was most interested in their reproductive behaviour.
It was this "fascination" that led him to do his PhD on reproduction and hibernation in bats. Among the discoveries he has made is that some young females "masculinise" their genitalia to avoid the unwanted attention of males before they mature, and that bats have variable gestation periods, a trait that makes them unique among mammals.
Professor Racey and his team have spent more than 20 years working on the conservation of bats in Madagascar, where they are not protected by law.
After netting a previously unknown bat during a trip to the island, he now has the honour of having a species, Pipistrellus raceyi, named after him. He said he considers this "a great privilege".
Professor Racey has won numerous accolades during his career. Last year, he was named one of BBC Wildlife's 50 Conservation Heroes, and he is due to receive a lifetime achievement award from the Bat Conservation Trust, which he helped to establish in 1990.
Having published more than 200 scientific papers and co-edited a number of books on bats, Professor Racey's research in the field is well known.
But he said it will be the supervision of his PhD students that he will miss the most: "I will miss helping my students move their science forward, it's satisfying to see them evolve and grow," he said.
Although he has retired, Professor Racey will continue his research in Madagascar, supported by a Leverhulme emeritus fellowship. He will also keep himself occupied with a visiting professorship at the Centre for Ecology and Conservation at the University of Exeter.