Territory selection in the city: can birds reliably judge territory quality in a novel urban environment?

Abstract

AbstractAlthough territory selection is likely to be under strong natural selection, in many cases it might be impossible for individuals to judge territory quality directly in terms of fitness return. Thus, animals often rely on some indirect environmental cues in territory assessment and they may not be able to make optimal settlement decisions when subjected to a novel environment. The aim of this study was to investigate adaptiveness of territory selection in a newly established urban population (Łódź, central Poland) of a waterbird, the Eurasian coot Fulica atra. For this purpose, we correlated occupancy rate of urban breeding territories over a 7‐year period with basic fitness‐related traits of coots. We found that the average number of fledglings raised by Eurasian coots increased with territory occupancy, indicating that birds were able to reliably judge territory quality and to choose nest sites which maximized their reproductive success. This conclusion was supported by the fact that in the process of territory selection coots used a set of habitat cues important for successful nest concealment and brood safety. In contrast, we found that coots showed no preferences for territories which provided easy access to anthropogenic food resources (via public feeding of waterbirds) and there was no relationship between condition of adult birds and territory occupancy, suggesting that either: (1) brood safety was a more important component in territory assessment than food availability, or (2) birds were unable to reliably judge food resources in a novel urban landscape.