The Degree of Urbanization of a Species Affects How Intensively It Is Studied: A Global Perspective

Abstract

The expansion of urban areas is currently one of the most important worldwide landscape changes. This process, termed urbanization, has important ecological effects and is known to alter many aspects of the biology of organisms (including birds). However, human-nature interactions can also be affected by this process. We hypothesized that urbanization can particularly affect how intensively we investigate birds. We predict that species living in close proximity to humans will be more easily or preferably studied, thus promoting a bias in research effort toward urban birds. In order to test this hypothesis we have collected a detailed database of urban and non-urban avian communities including information from five biogeographic realms and more than 750 bird species. We obtained four different indicators of research effort (two previously considered and two new ones) as well as information on different confounding factors that are known to affect research effort such as conservation status, body mass, distribution range and phylogeny, in addition to the previously unconsidered historical factor of year of description of the species. We found a positive and significant association between the degree of urbanization of a species and how frequently it is investigated. We also found the expected effect for biogeographic realm, body mass and distribution range, and year of description, but not for conservation status. In addition, we found a strong correlation among all research effort variables which support the use of Google Scholar as a reliable source for these kind of studies. Our findings suggest that urbanization is not only affecting the biology of organisms but also how we study them. These results might have important implications if this research bias is maintained in the long term. Future investigation should aim at exploring the ultimate reasons for this research bias toward urban birds and whether it is also happening for other groups of organisms.

Drivers of taxonomic bias in conservation research: a global analysis of terrestrial mammals

“…This finding parallels several studies that have shown a strong geographical correlation between the presence of a research centres and a high density of biological records and conservation research (e.g. Schulman, Toivonen & Ruokolainen, 2007; Amano & Sutherland, 2013; Engemann et al , 2015; Ibáñez‐Álamo et al , 2017; Correia et al ., 2019; Lessa et al . , 2019).…”

“…This finding parallels several studies that have shown a strong geographical correlation between the presence of a research centres and a high density of biological records and conservation research (e.g. Schulman, Toivonen & Ruokolainen, 2007;Amano & Sutherland, 2013;Engemann et al, 2015;Ib añez-Alamo et al, 2017;Correia et al, 2019;. Such geographical biases in research are likely to be reduced in the future if few research capacity countries invest greater amounts of resources in science (Fazey et al, 2005b) and consequently insert more conservation qualified researchers in areas with low research capacity.…”

“…Indeed, environmental science capacity of countries within the range of a species was strongly associated with research effort for both components of our hurdle model. This is most simply explained as a consequence of conveniently located study populations overlapping with a qualified 'corpus' of conservation researchers (Fazey, Fischer & Lindenmayer, 2005b;Meyer et al, 2015;Ib añez-Alamo, Rubio & Bitrus Zira, 2017). Such a consequence inevitably leads to a mismatch between conservation research effort and conservation research need which is higher in the world's most biodiverse countries in the global south (Fisher et al, 2011).…”

Urbanisation and nest building in birds: a review of threats and opportunities

“…This is probably a consequence of anthropogenic nesting materials being more commonly used as lining material, although some taxa such as thrushes (Turdidae) seem to use them as structural material as well (Biddle et al 2016). Many turdids are among the most common urban bird species (e.g., Wang et al 2015;Ibáñez-Álamo et al 2017bIbáñez-Álamo et al , 2018, which makes them excellent candidate subjects for further study.…”

Great tits and the city: Distribution of genomic diversity and gene–environment associations along an urbanization gradient

“…Lastly, statistical approaches to consider polygenic signals, by estimating polygenic scores of adaptation (Berg & Coop, ; Gagnaire & Gaggiotti, ; Stephan, ), identifying gene sets (Daub et al., ; Gouy et al., ), and partitioning additive variance throughout the genome (Robinson et al., ; Santure et al., ) will probably be of high interest in this context of polygenic adaptation. These research aims are likely to be tested in the near future thanks to an increasing interest in recent years in both polygenic adaptation (Berg & Coop, ; Boyle, Li, & Pritchard, ; Pritchard et al., ; Purcell et al., ; Yeaman, ) and urban ecology research (Alberti et al., ; Hendry et al., ; Ibáñez‐Álamo, Rubio, & Bitrus Zira, ; Johnson & Munshi‐South, ).…”