Decrease in bird species richness and abundance after post-COVID-19 public reopening on paths of a high-attendance protected area

Abstract

Context Protected areas (PAs) receive visitors pursuing environmental education and recreation objectives, but this can negatively affect the conservation of their biodiversity. Quantification of this impact is scarce, especially in developing countries. The Anthropause generated by the COVID-19 lockdown constituted a remarkable change in human activities and a good opportunity to investigate wild biota in the absence of people. Aims The objective of this study was to quantify the impact of visitors on the richness and abundance of birds on the paths of an Argentine protected area with high visitor traffic (~1 million people per year). Methods Birds perched on the paths (ground and surrounding vegetation) were recorded weekly during 12 days in the years 2020 (closed to visitors) and 2021 (open to visitors). Each day, 10 points were sampled and each point was recorded for 15 min. Key results Both the time of the survey and the opening to visitors were relevant factors in explaining the richness and abundance of birds. In general, a decrease in both variables was recorded as time passed after dawn and when there were visitors compared to when there were no visitors. At the mean value of time, the decrease in bird records associated with visitors was 49% for richness and 65% for abundance. Ground-perched birds showed no increased sensitivity to visitor exposure, because recording percentages remained consistent across both study years. Conclusions The results of this work suggest a benefit for wildlife in natural areas during the Anthropause of 2020. Implications Regarding management applications it is suggested to minimise the number of paths, so as to concentrate and limit negative effects, and to enhance the structural and floristic complexity of pathside vegetation.