Uncovering the Effects of COVID-19 Mask Wearing on Bird Flight Initiation Distance in Urbanized Areas in the Southern Philippines

SIMPLE SUMMARY: The COVID-19 pandemic has caused changes in human behavior, such as wearing masks and reducing public activities, which have also affected the behavior of urban wildlife. However, the impact of COVID-19-related activities, particularly mask wearing, on urban wildlife is not yet fully understood, especially in the Philippines, where COVID-19 mask wearing restrictions persisted longer than in other nations. To address this, we assessed the response to mask wearing of two common urban bird species by examining their flight escape strategies, such as alert and flight initiation distances. Our study showed that mask wearing reduces bird vigilance against intruders, but the response was species-specific. ABSTRACT: The COVID-19 pandemic has caused significant changes in public and human activities worldwide, including using masks and reducing human interaction. These changes have also affected wildlife behavior, especially in urban areas. However, there is limited understanding of the impact of COVID-19-related human activities, mainly mask wearing, on the behavior of urban bird species. This case is intriguing in the Philippines, where COVID-19 restrictions and mask wearing have been more prolonged than in other countries. We studied two common urban bird species (Geopelia striata and Passer montanus) in Southcentral Mindanao, Philippines, to assess their response to mask wearing by examining their alert distance (AD) and flight initiation distance (FID). We found that birds had a reduced FID to mask wearing, but only significantly in G. striata (Zebra Doves) and not in P. montanus (Eurasian tree sparrow). The effect of the variables related to urbanization on FID was contrasting. For example, ambient noise increased bird vigilance while proximity to roads reduced bird FID in urbanized areas, but their effects were weaker compared to mask wearing. We conclude that mask wearing during the COVID-19 pandemic is a significant environmental element that alters bird escape responses in urban areas, and the effects may be species-specific.