Data from: Eurasian tree sparrows are more food neophobic and habituate to novel objects more slowly than house sparrows

Most research on the variables that allow for introduced species to succeed and become invasive has focused on environmental and ecological factors. Fewer studies have assessed the roles of behavioral and cognitive traits. To help fill this knowledge gap, we studied neophobia, aversive behavior towards novelty, in the non-native Eurasian tree sparrow (Passer montanus), and compared results to previous work in a more successful invasive congener, the house sparrow (Passer domesticus). We assessed the neophobia of wild-caught Eurasian tree sparrows by measuring their responses to novel objects and novel foods and their ability to habituate to initially novel objects. We predicted that Eurasian tree sparrows, as less successful invaders, would overall be more neophobic than house sparrows. Although we did not observe differences in neophobia towards novel objects in the two species, Eurasian tree sparrows were significantly less willing than house sparrows to try novel foods. Eurasian tree sparrows were also slower to habituate to repeated presentations of the same initially novel object compared to house sparrows. Multiple factors certainly influence invasion success, but our results suggest that neophobia might limit the success of an introduced species in novel environments.