Consistent Individual Differences in Social and Solitary Foraging Within Disparate Taxa

Any pet owner can tell you that their pet is unique. They have behavioral traits that are consistent over time that also make them different from other pets. However, until recently ecological studies have dismissed individual differences in behavior as statistical noise around an adaptive mean. This has changed in the last few decades, as more and more often consistent individual differences, or personalities, are being treated as an evolutionary “feature” rather than a “bug. Foraging is an ecologically important behavioral context in which animals should exhibit consistent individual differences. I examined individual-level foraging in three dissimilar taxa: a solitary crustacean, the rusty crayfish (Faxonius rusticus), a eusocial rodent, the naked mole-rat (heterocephalus glaber), and a colonial chiropteran, the Egyptian fruit bat (Rousettus aegyptiacus). Individual rusty crayfish varied in their foraging behavior but were consistent over time. They also harvested more food but were more neophobic than a native conspecific they are displacing, the Northern clearwater crayfish (F. propinquus). In naked mole-rats, foraging effort is concentrated in just a few mid-sized individuals, and their inefficient foraging strategies suggested a lack of information sharing. Naked mole-rats also exhibited clear personalities, but the relationship between personality and size varied between colonies. Finally, in Egyptian fruit bats, male-female pairs foraged more efficiently than same-sex pairs. However, foraging was affected more by the identity and compatibility of individuals than on sex or social context. Overall, these results suggest foraging behavior is not just a relevant context in which animals show consistent individual differences, but an overlooked method by which to measure them.