A comparison of problem-solving success between urban and rural house sparrows

Abstract

Behavioural flexibility is an important component of adaptation because it can help animals to exploit new or diverse habitats. Due to abundance of novel objects and resources provided by humans, urban environments may select for behavioural flexibility, but empirical evidence for this hypothesis is controversial. In this study, we compared urban and rural house sparrows (Passer domesticus) in four foraging problem-solving tasks. In the most difficult task, urban birds with large body mass were faster than others. Urban and rural birds performed similarly in the three easier tasks and did not differ in their learning efficiency. Individuals successful in one task tended to be successful in other tasks, and the repeatability of performance did not differ between urban and rural birds. Individuals that attempted to access food more frequently solved the problem faster in all tasks, but urban and rural birds did not differ in the frequency of attempts. These results suggest that the effects of urbanization on problem-solving success are weak and context-dependent in house sparrows. We propose that while urban animals may be better at exploiting some aspects of novel environments than rural conspecifics, such differences may be modulated by other habitat effects such as reduced nestling development and adult body mass in urban sparrows, which might influence some long-term determinants of innovativeness such as cognitive capacity or physical skills.