Rapid behavioural response of urban birds to COVID-19 lockdown

Biodiversity is threatened by the growth of urban areas. However, it is
still poorly understood how animals can cope with and adapt to these rapid
and dramatic transformations of natural environments. The COVID-19
pandemic provides us with a unique opportunity to unveil the mechanisms
involved in this process. Lockdown measures imposed in most countries are
causing an unprecedented reduction of human activities giving us an
experimental setting to assess the effects of our lifestyle on
biodiversity. We studied the birds’ response to the population lockdown by
using more than 126,000 bird records collected by a citizen science
project in northeastern Spain. We compared the occurrence and
detectability of birds during the spring 2020 lockdown with baseline data
from previous years in the same urban areas and dates. We found that birds
did not increase their probability of occurrence in urban areas during the
lockdown, refuting the hypothesis that nature has recovered its space in
human-emptied urban areas. However, we found an increase in bird
detectability, especially during early morning, suggesting a rapid change
in the birds’ daily routines in response to quieter and less crowded
cities. In conclusion, urban birds showed high behavioural plasticity to
rapidly adjust to novel environmental conditions, such as those imposed by
COVID-19.