In French cities, the constant background noise of cars, trucks and passersby was abruptly replaced by silence two weeks ago when the government imposed a nationwide lockdown to stem the spread of the deadly COVID-19 pandemic.
This unusual silence was initially only interrupted by the distant din of sirens as health professionals raced to tend to the sick, but an altogether new sound has emerged: birdsong.
Could the confinement lead to a resurgence of wildlife activity?
Blandine Doligez, a researcher from the Laboratory of Biometrics and Evolutionary Biology (LBBE) of the University of Lyon 1, specialises in the study of birds.
She told Euronews this government-imposed lockdown is indeed conducive to animals changing their habits to venture out of "their usual bases".
"Studies carried out in urban areas on bird populations have already highlighted the role of the level of disturbance, such as the intensity of human passage near nests, on different parameters of the reproduction," she explained.
She noted for instance that birds in cities have been shown to sing more on Saturdays and Sundays because the level of disturbance from humans is lower than on weekdays.
The presence of humans is not the only source of disturbance for birds, she stressed, "the same is also observed for sources of noises, chemical, light pollution".
France is not the only European country currently on lockdown with most of the bloc's 500 million citizens asked to stay at home, resulting in a drop of activity and the grounding of most flights.
This has led to a fall in greenhouse gas emissions and a reduction in atmospherical pollution.
'Landscape of fear'
The confinement has also had an impact on mammals, according to Jean-Michel Gaillard, director of research at the National Centre for Scientific Research (CNRS).
"Quite simply because space usually occupied by humans and their activities has become vacant and it has become space available for animals who will integrate it into their environment," he told Euronews.
"The presence of human activity is interpreted (by animals) as something negative, dangerous and faced with this disturbance, animals increase their flight distances or will even completely abandon areas they previously used.
"But as soon as there is a change in the so-called "landscape of fear" — or the threats which can exist in any given place — animals update their map of threats. Most mammal species know how to adapt to these changes really well. This is called plastic behaviour so when animals observe — and this is very, very, fast — that nobody is there, they will settle down," he explained.
Not all animals have the same reflexes however and some remain very fearful for longer, Gaillard continued.
In the UK, where foxes are a regular sight in cities, they've become even more prominent.
"Deers are the same. They're regular garden visitors, it's not something new. But since no one is occupying the space at the moment, they come much more frequently and in much greater number," he pointed out.
However, this is unlikely to become the new normal and lifting the confinement will spell a return to the status quo.
"As soon as we return to normal, it is certain that we will very, very, very quickly go back to a the situation we knew before," he said.
For researchers, the lockdown and the subsequent impact on wildlife behaviour is a catch-22 situation because as Doligez stressed "it represents an experience on an exceptional scale, unmatched to date, across an entire country or even a continent" that they cannot study because they're stuck at home.
"This would provide a wealth of particularly important and interesting information on the impact of human activity on wild bird populations in urban areas," she said.
If the confinement lasts until May, researchers also won't' be able to carry out their usual capture and tagging campaigns, Gaillard added.
"This period is certainly interesting in theory, but unfortunately, there will be no one to monitor it," he lamented.