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

Introductions of non-native species throughout the world have had severe ecological consequences. However, most research has focused on environmental and ecological factors that allow for introduced species to succeed and become invasive, with fewer studies assessing the roles of behavioural and cognitive traits. To help fill this knowledge gap, we studied neophobia, an aversion 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...