Determining homing abilities of nesting male threespine stickleback ( Gasterosteus aculeatus )

Homing behavior allows individuals to return to a home site when displaced, presumably increasing fitness by increasing access to known food resources, refuges from predators, and breeding opportunities. Homing has been demonstrated in Gasterosteus aculeatus, also known as the threespine stickleback. We hypothesized that because stickleback males guard a nest and tend to the eggs and fry, they should be particularly incentivized to home. In an experiment, we marked and displaced nesting male stickleback over a variety of distances to see how far they were able to home and whether homing success declined with distance displaced. We found that stickleback males did home, which is consistent with other studies. Additionally, we found that the return probability decreased with distance displaced, though not significantly. However, some nests were clearly occupied by new, unmarked males after displacement, meaning that even if an experimentally displaced fish returned, they might not have been able to regain their nest. Removing these cases from the data strengthened the expected negative relationship between distance and return, suggesting that stickleback use landmark cues to navigate home.