Glasgow scientists probe listening likes of lemurs

However, researchers are still unsure exactly what sounds the animals enjoy, although it should come as no surprise that the susurrations of the rainforest are among the most pleasing to lemur ears. 

One hip lemur seemed to enjoy music, while others simply relaxed to white noise. The sound of traffic was also a surprise success on the lemurs’ hit parade.  

The lemurs' listening preferences were revealed after scientists from the University of Glasgow teamed up with zookeepers at Blair Drummond Safari Park to explore whether interactive technology which plays sounds on demand could enrich the wet-nosed primate’s everyday lives. 

Researchers made a wooden box lined with infrared sensors - dubbed the ‘LemurLounge’ - which played a rotating selection of sounds when the animals entered. 

The system, the first of its kind to be tested with lemurs, suggests that although they have no single favourite type of sound, they do seem to prefer sound over silence when given the choice.  

Their interactions also vary across species and between individuals within species groups, which could suggest that, like humans, lemurs have their own preferences for how they interact with devices. 

A lemur investigates the lemurlounge (Image: University of Glasgow)

The prototype LemurLounge was installed in lemur enclosures at Blair Drummond, which is home to black-and-white, brown and ring-tailed lemurs – 14 animals in total.   

Speakers inside the box played the sounds of a rainforest, city noise, upbeat music, calm music or white noise for as long as the lemurs chose to remain in the lounge.  

From time to time during the study, the speakers played no audio at all to help determine if the lemurs preferred to have quiet time inside the LemurLounge. 

Researchers found visits to the LemurLounge increased when speakers played sounds, with the animals’ preferences varying across the three species which shared access. 

READ MORE: Ukraine and Scotland team up for citizen archaeology project

Common brown lemurs triggered sounds for around two seconds at a time, while their black-and-white and ring-tailed counterparts stayed longer, for about four seconds. Older lemurs also spent more time with triggered sounds than their younger counterparts, and played them more often. 

The team also observed significant variation in interactions with the LemurLounge between individual lemurs. One black-and-white lemur interacted with sensors twice as much as the others in his species group, and spent four times as much time there.  

Another triggered music most frequently and chose white noise the least, while two others did the exact opposite. 

Ilyena Hirskyj-Douglas (left) and Vilma Kankaanpaa (right) (Image: University of Glasgow)

The research is the latest outcome of an ongoing partnership between zookeepers at Blair Drummond Safari Park and researchers at the University of Glasgow’s School of Computing Science, led by Dr Ilyena Hirskyj-Douglas. 

Previous research collaborations between the zoo and the university have included the development of the world’s first interactive enrichment system for giraffes. Dr Hirskyj-Douglas has also led related research projects which investigated white-faced saki monkeys’ response to interactive audio in their enclosures. 

READ MORE: Cancer research in Scotland handed £7m funding boost

Dr Hirskyj-Douglas said: “Our partnership with Blair Drummond Safari Park gives us the chance to start mapping out what a future of animal-computer interaction might look like. It builds on a wealth of previous research showing that audio enrichment could benefit zoo animals’ wellbeing. 

“This research is the first time that zoo-housed lemurs have been given the opportunity to interact with a computer enrichment device. Their reactions to the LemurLounge gives us fresh insight into their behaviour and preferences, and could help inform the development of systems for lemurs and other species in the future.”

The findings could help inform the development of more fully-featured digital enrichment systems for lemurs living in zoos, and help advance the emerging field of animal-computer interaction.  

The research will be presented as a paper at the Association of Computing Machinery CHI conference on Human Factors in Computing Systems next month. 

A lemur listens at the lounge (Image: University of Glasgow)

Vilma Kankaanpää, of the University of Glasgow’s School of Computing Science, is the paper’s corresponding author.  

She said: “Our findings suggest that future enrichment systems for animals of different species which live together in enclosures should take the variation in their preferences into account at the design stage. 

“The computer systems humans use in our everyday lives were developed through intensive research into users’ needs and preferences. In order to build the best possible interactive systems for animals in the future, we’ll need similarly focused research into what works for them. This study is one step further towards a future where zoo animals have access to digital devices which can enrich their lives.” 

Alasdair Gillies, Blair Drummond Safari Park’s Research Coordinator, said: “For us keepers, these findings come as no surprise. Our interactions with these animals grant us the privilege of witnessing their many varied idiosyncrasies on a daily basis. It will be fascinating to see how we can utilise these learnings going forward.”