Similar tolerance of urban birds towards both benign human and lethal cat predators

Prey animals make crucial escape decisions when confronted by predators. Previous research, predominantly employing human surrogates, has consistently shown that urban-dwelling prey exhibit greater tolerance for the approach of human beings compared to their counterparts in rural or suburban habitats. However, it is essential for urban animals to retain sensitivity to genuine predators despite their habituation to non-lethal human presence. In this study, we investigated the escape behavior of three bird species (Pica pica, Streptopelia orientalis, and Spilopelia chinensis) in response to both human and genuine cat predators. We compared the flight initiation distance (FID) and distance fled (DF) when approached by one person, one person with a cat, and two persons in urban and suburban environments. Our findings reveal that urban birds exhibit heightened tolerance (habituation) to approaching predators in urban environments. However, contrary to our expectations, urban birds showed similar FID and DF when approached by one person with a caged cat compared to one or two persons, suggesting a lack of distinction between human and cat predators or reluctance to make different escape decisions. In addition, DF was significantly influenced by the distance to refuge but did not differ between urban and suburban habitats. Our study supports the general risk-taking hypothesis, indicating similar reactions to different predators, and underscores the appropriateness of using human surrogates to study escape behaviors, even in habituated urban environments.