Influence of COVID-19 lockdown and hunting disturbance on the activity patterns of exotic wild boar (Sus scrofa) and axis deer (Axis axis) in a protected area of northeastern Argentina

Abstract

Wildlife diel activity patterns are relevant for studying animal responses to human disturbance and management of overabundant and invasive species. Exotic wild boar (Sus scrofa) and axis deer (Axis axis) in a protected area of northeastern Argentina have been intensely managed through controlled shooting over bait since 2006. This program kept wild boar at bay but failed to curb axis deer numbers for unknown reasons possibly related to the timing of hunting sessions. We used camera traps to assess the seasonal diel activity patterns of both ungulates over 2017–2021 and to test whether hunting-related activity and COVID-19 lockdown modified those patterns, and whether hunting-shift intervals overlapped with ungulate core activity. Wild boar activity strongly differed between summer and winter, showing cathemeral activity in summer and nocturnal activity in winter. Axis deer cathemeral activity displayed moderate inter-seasonal and inter-annual changes. The activity cores largely differed between both ungulate species. The lockdown-related suspension of hunting and other park operations over roughly 1 year did not modify the seasonal activity patterns of wild boar, whereas axis deer increased its daytime activity in summer. Ungulate activity remained consistent over successive 48-h interval preceding, accompanying, and following hunting sessions, suggesting that short-term hunting-related disturbance did not influence their temporal activity. Unlike wild boar, detection of axis deer was substantially higher during intervals matching overnight hunting shifts rather than during evening shifts. Matching the timing of hunting sessions to ungulate activity cores (i.e., night hunting) may substantially increase culling and the efficiency of management efforts.