Image credit: Yuval Barkai (CC BY 4.0)
Lockdowns due to the COVID-19 pandemic reduced human activity in early 2020, providing a rare opportunity to examine how wildlife behaves when humans are absent. While several studies reported increased abundance of animals in urban habitats, others cast doubt on these reports. Variation in study conclusions could be due to different species showing different levels of adaptation to human activity. Additionally, studies that rely on visually observing animals can impact their behavior and those based on public reporting may also have been influenced by changes in human activity. Therefore, it remained unclear whether COVID-19 lockdowns impacted wildlife and how this might differ among species.
To quantify wildlife presence and activity during lockdown, Sun et al. placed recording devices in different urban environments, including roads, residential areas, and urban parks across Tel Aviv in Israel during early 2020. This allowed continuous monitoring of bird vocalizations during lockdown and non-lockdown periods and ensured the birds were not disturbed by human observers.
Three common bird species, which each show different levels of adaptation to urban ecosystems, were monitored. The hooded crow, which depends heavily on human resources, and the rose-ringed parakeet, an invasive alien species which has adapted to exploit human resources, decreased their activity in most urban habitats during lockdowns. On the other hand, the graceful prinia, which has adapted to thrive in urban green spaces but is relatively shy of humans, showed increased activity, especially in parks where humans were absent.
The findings of Sun et al. reveal that birds show species- and habitat-specific changes to their behavior as a result of decreased human activity. This might explain why previous studies – which did not perform habitat-specific analyses – gave conflicting reports of the impact of COVID-19 lockdowns on wildlife activity. The results also demonstrate the value of different habitats within urban environments for animal activity, specifically identifying the importance of urban parks. By highlighting the impact of human activity on urban wildlife, the findings provide a scientific basis for future conservation efforts.
