The behavior of invasive geckos in human-dominated landscapes: A role for boldness

The behavior of individuals can influence the success of invasive species and the impact on residents. Previous studies of tropical house geckos demonstrated that invasive species can out-compete residents through exploitation of limited resources. The competitive advantage of one invader was dramatically affected by structural features of human-altered habitat. Structure altered foraging success and agonistic interactions and invaders and residents were affected differently. Lepidodactylus lugubris is a parthenogenetic gecko that comprises four major clones. One clone is becoming numerically dominant to other clones on many Pacific islands. We tested the hypothesis that A clones have a general foraging advantage over D clones, and the nature of this advantage is due to higher levels of aggression and social dominance. We also tested whether any behavioral or competitive advantage is enhanced in structurally simple habitats. We found that A clones had inherently higher consumption rates than D clones and this advantage became more pronounced when clones foraged together. Increased habitat structure affected foraging tactics and reduced overall levels of agonism, but it did not alter the foraging advantage of A clones. The foraging advantage was not attributable to social dominance or overall levels of activity. Instead, D clones defended and used shelter more than A clones, which spent long periods of time in the open. We conclude that boldness can result in a greater capacity to exploit insect resources and be an advantage for invasive species in the human dominated landscape of the tropical Pacific.