Covid-related surge in global wild bird feeding: Implications for biodiversity and human-nature interaction

providing supplementary food for wild birds can be beneficial for them in terms of survival during periods of resource scarcity [16] and improved health [17], there is also evidence to suggest that bird feeding may alter ecological communities and potentially have negative effects on biodiversity [20]. It is, therefore, imperative that we understand the global extent of bird feeding in order to gain a more comprehensive understanding of its potential impacts on both avian and human well-being at a continental and global scale. Future work should further explore bird feeding patterns in parts of the world with limited formal data collection and increase the cultural and biophysical diversity of settings where local bird feeding is studied. Given the widespread practice of bird feeding at a global scale, we sought to examine whether there is a correlation between environmental factors, such as bird species richness, and interest in bird feeding. Our analysis revealed that countries and territories with higher biodiversity, as measured by the number of bird species present, tended to have a higher level of interest in bird feeding. We also found that interest in feeding birds was shared across lati- tudes. As initial lockdowns occurred in February and April 2020, corresponding to spring for the northern hemisphere and fall for the southern hemisphere, this suggests a trend towards year-round bird feeding instead of winter-only [1]. Though we found a relationship between bird species richness and bird feeding, we do not claim that a greater number of bird species is

the reason for the difference. Future work should continue to describe patterns in factors that can be associated with bird feeding interest, including socioeconomic and geographic factors, such as income and latitude, with a goal of eventually estimating causal drivers of bird feeding. Documenting the presence and absence of interest in bird feeding is the first step to under- standing global patterns. A limitation of our study is that we do not characterize how bird feeding varies across countries that show interest in feeding through Google Trends. Future work should investigate bird feeding intensity, for example, the per capita practice of bird Table 2. Relationship between the existence of search interest for "bird feeder" and bird species richness. (1) (2) (3) Bird Species Richness (medium) 0.480*** 0.479*** 0.127* (0.09) (0.077) (0.073) Bird Species Richness (high) 0.121 0.443*** 0.021 (0.084) (0.083) (0.083) Internet Access 0.010*** 0.002* (0.0010) (0.001) GDP 0.140*** (0.015) Constant 0.364*** -0.323*** -3.010*** (0.062) (0.103) (0.296) Observations 172 172 172 R2 0.145 0.37 0.587 Note: *p<0.1; **p<0.05; ***p<0.01 Results show the relationship between the existence of search interest (binary, existence of search interests = 1, absence of search interests = 0) and bird species richness (binary variables for the tercile of the number of bird species) using a linear probability model.

Internet access is controlled in Columns (2) and (3), which is measured as the percentage of populations using internet in each country or territory. GDP is controlled in Column (3). https://doi.org/10.1371/journal.pone.0287116.t002 PLOS ONE Covid-related surge in global wild bird feeding PLOS ONE | https://doi.org/10.1371/journal.pone.0287116 August 2, 2023 11 / 15