The Arts and Sciences used to share much of the same intellectual space. Only recently have they diverged to the degree that they seem diametrically opposed. The Exchange is our attempt to rekindle some of the dialogue that occurred between the two fields.
In this installment, we’ve brought together singer-songwriter Stella Donnelly and evolutionary biologist Michela Corsini.
Stella Donnelly is a Welsh-Australian indie rock singer-songwriter and guitarist. After the success of her debut EP Thrush Metal in 2017, she signed with Secretly Canadian in 2018. She released her debut studio album Beware of the Dogs to critical acclaim in March 2019, peaking at number 15 on the ARIA Album Charts and winning Independent Album of the Year at the AIR Awards. Her second album, Flood, was released in August 2022, debuting at number 29 on the ARIA Charts.
Michela Corsini is a postdoctoral researcher at Barber Sensory Ecology Lab, Boise State University, Idaho, USA. Her postdoc is focused on the effect of light pollution on bats, moths and people.
As wildlife biologist, she have always been interested in human-wildlife interactions and in how human activities and habitat transformation influence wildlife. She has worked in different countries (Switzerland, Austria, Italy, Poland, United States) and studied a wide range of mammal and bird species (including red fox, roe deer, blackgrouse, capercaillie, american mink). Her Ph.D. research focused on the effects of urbanization on behavioral and life-history trait variation of two passerine species: the blue tit (Cyanistes caeruleus) and the great tit (Parus major).
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Stella Donnelly: How do animals adapt to more industrial and traffic noise, and are human brains impacted by constant noise pollution too?
Michela Corsini: More than half of the human population lives in cities, novel human-modified ecosystems where invisible polluted soundscapes influence the life of any organisms inhabiting the urban and neighboring environment, both on land and underwater. However, the way sound pollution affects each taxonomic group varies depending on the frequencies a species is able to hear.
Humans, for example, hear sounds between 20 Hz and 20 kHz, a frequency range described in many bird species, which, differently to us, respond with lower sensitivity in the upper half of the range. Other animal species can hear frequencies beyond the human hearing range: this is the case for many species of bats and dolphins, which can hear frequencies over 100 kHz. Mice and rats hear less well below 20 kHz. This variation in sound hearing, along with the sound duration, spectrum, temporal pattern and distance to the source, generate a wide range of responses from the animal world, which may change across time, contexts, between and within species (and their respective experiences).
Animals can get used to a non-threatening and repetitive sound characterized by the same intensity (that also explains why some sound-induced deterrent systems reveal not efficient in the long run). I remember seeing European starlings feeding on cherries next to “bird scare cannons” in Italy: despite the loud sound emitted at regular intervals by the cannons, the birds didn’t leave the area.
On the other hand, initially frightening sounds may later be linked to positive experiences (such as the possibility to access easy-food) and, thus, attract animals. Tools with the scope of deterring potential predators like pingers (small battery-powered acoustic alarms attached at intervals along a fishing net), may possibly become a “dinner bell” for dolphins, causing a lethal entanglement in the fishing nets.
Among all ecosystems studied, cities offer a unique scenario for scientists to investigate how sound pollution influence wildlife. Although some species decline with higher levels of noise, others adjust their vocal signals to be more audible under noisy conditions.
For example, researchers in Panama City found that male calls in urban tùngara frogs were more elaborate than those of their non-urban conspecifics. When moved to the forest, urban frogs switched to “less-showy” songs, most likely to avoid rural predators and parasites (in fact, bats and midges are also attracted to tùngara frogs’ calls).
In an experimental study conducted on Asian parti-coloured bats, the authors found that individuals exposed to chronic traffic noise while roosting may need more energetic intake than conspecifics occupying quieter locations. This is probably a stress-response consequence; in fact, traffic noise may increase metabolic dysregulation and the risk of other diseases.
Other researchers recorded bird songs in Rock Creek Park (Washington DC) and reported that the Eastern wood pewee attempted to make its songs heard over the track of traffic noise played in the background. However, such effort to be heard didn’t seem to make a difference for their conspecifics, whether it was a mating call or a male defending its territory.
Analogous dynamics were described in sparrows living in San Francisco and in Great tits living in Leiden (the Netherlands), where birds sing higher notes to overcome the low roar traffic. Other species, like the European robin inhabiting Sheffield and surroundings, have learned to sing at night in areas where the noise levels were 10 decibels louder during the day.
Some scientists argue that, if cities soundscapes go in the opposite direction by reducing the main sources of noise (for instance, by using self-driving electric cars instead of gas vehicles), birds and other species may go back to their old songs and habits. Thus, as the city life get louder, wildlife changes to adapt to its noise.
As for your second question, yes, human brains are impacted by constant noise pollution. The exposure to moderate levels of sound pollution may lead to irritation, sleep disturbance, chronic stress, reduced speech intelligibility and working performance (with important consequences on all the other aspects of communication and social life). The exposure to noise can cause short-term impairments in cognitive function, with people exposed to noise struggling to remember or focus while addressing their routine tasks.
However, it is important to emphasize that such responses commonly found in urban residents may derive from more than one factor or/and from their interaction. Indeed, urban areas characterized by high levels of noise, are also exposed to high levels of air and light pollution, and by the presence of people with a lower socioeconomic status. There is evidence that each of these factors may act as a stressor and, thus, can increase dementia risks: more studies are needed to tease apart the role played by sound pollution in this respect.
Although it is clear that sound pollution influences many species (humans included) by changing their behavior or physiological response (for example, by increasing stress levels) as illustrated above, only few studies have demonstrated how that translate into consequences for individual survival and reproductive success.
In a study showing that noise may reduce nesting species richness, the authors found that avian reproductive success (measured as the number of fledged nestlings) was higher in noisy environments: this is more likely due to the fact that sound pollution disrupts predators.
Thus, the impact of sound pollution may go beyond a single individual, and act at the level of between and within species interactions, with important consequences at the population and ecosystem levels. Even though the scientific community is aware of the large scale-impact exerted by polluted soundscapes, more studies and experimental evidence are needed to better comprehend these dynamics.
Michela Corsini: I am very curious to know your point of view from the stage on aspects of the audience. Do you notice a difference in behavior in people attending your concerts from different areas? Is the audience was more chaotic, or calmer, or something in between? In particular, did you notice differences between large cities, smaller towns and villages, etc? It’s true that people may travel long distances to follow their favorite artist, but locals are more likely to form the largest part of the audience, I guess.
Stella Donnelly: Thanks for your question! From the four years I have spent touring I have definitely noticed differences between crowds depending on the area I am playing in. From my experience, the biggest factor in are the cultural differences from town to town, city to city and country to country.
In Australia, a lot of live music is tied around drinking and pub culture, so certain places are more rambunctious than others and I can expect more noise in the crowd, which creates amazing energy for shows.
In other places like South Korea there is no alcohol served at the show which makes for a more formal environment, which is special in its own way because it’s a quiet and attentive crowd.
In highly populated countries like USA or the UK, each city has its own live music culture and no two gigs are the same!
I always enjoy playing in a smaller town where touring acts might not always come through. Though the gigs are smaller, I can feel the gratitude in the crowd for having come especially to their town.
Being from Perth, Western Australia, one of the most isolated cities in the world, I was always so grateful to artists for spending the money and time coming to play in our home!
There are many other variables like the way the venue is set up and which night of the week we’re playing that impact the crowd interaction but aside from these factors I can definitely notice shifts in crowd interaction as I travel through the world!
This is so interesting! Hearing about Stella’s own experiences is extra special since I had the chance to see her live last year!