Changes in roe deer (Capreolus capreolus) daily activity patterns in Warsaw during the COVID-19 pandemic

Abstract The COVID-19 pandemic, which modified levels of visitor attendance to urban forests and green spaces, provided a unique opportunity to measure the effects of human presence on wild animals and their activity. The aim of our study was to describe how the daily activity pattern of roe deer (i.e. proportion of day- and night-time observations) changed in response to visitor frequency in urban forests of Warsaw in four periods of 2020 (the year the COVID-19 pandemic was announced) compared to the same periods in 2019 (control year). In total, 662 observations of roe deer were recorded by camera traps in both years. The frequency of roe deer observations in urban forests of Warsaw in day- and night-time did not differ between March 2019 and 2020 (period before lockdown, no changes in the number of visitors). Next, between 1 and 20 April 2020 (national lockdown; urban forests were closed for public) the activity of roe deer increased during the day-time. Between 21 April and 30 June in both 2019 and 2020 the frequency of roe deer observations in day and night-time did not differ (green areas were reopened, remote learning). Finally, in July–August 2020 (summer holidays, tourist traffic in forests elevated all day round) the activity of roe deer visibly increased during the night-time. Our research shows how their activity rapidly shifted toward day-time when forests were closed for visitors, and toward night-time when the number of visitors was higher in urban forests after the lockdown. To summarize, roe deer in urban forests showed high ecological plasticity to human presence and rapidly adjusted to changes in the number of visitors in urban forest during the COVID-19 pandemic.