The ultimate causes of personality in Darwin’s finches

The Galapagos Islands are a biodiversity hotspot, but many species are in decline due to the threat of introduced, invasive species. To address this issue, the Galapagos National Park Directorate has implemented an island-wide eradication of invasive rodents and feral cats on Floreana Island. This project measures the ecological recovery of the extant Darwin`s finch species and the only native predator of Darwin`s finches on Floreana Island, the Galapagos Short-eared Owl. Darwin`s finches are a textbook example of an adaptive radiation, with 17 species evolving in just 1.5 million years. This group is known for morphological differences related to dietary niche and food consumption, with birds of different beak size and shape exhibiting different foraging techniques. Surprisingly little is known about the behavior of Darwin`s finches and how behavioral differences between individuals and populations affect their success and persistence, a gap in knowledge that this project aims to fill. Personality is a shorthand term for individual behavioral differences that describe how animals behave in response to external conditions, for example, whether individuals are confrontational or averse to risk. Risks can be in the form of danger, novelty, or social situations. We have developed rapid field assessment techniques to measure animal personality in the wild. In this study, we use these techniques to measure changes in the personality structure of prey and predator populations under highly variable conditions of predation risk and prey availability. We compare our variables of interest before and after the island-wide removal of invasive predators and before and after the native predator, the Short-eared Owl, is reintroduced back onto Floreana Island after being held in safeguard captivity for two years to protect it from the poison used in the rodent and cat eradication. This means that the owl will be the only native predator of Darwins finches after their reintroduction in 2025. We will use drone technology to monitor GPS-UHF-tagged owls and VHF-tagged Darwin`s finches, providing unprecedented information on the temporal and spatial occurrence of both predators and prey on Floreana Island before and after invasive species control. The results of this study are expected to provide the most comprehensive dataset of individual- level movement and behavioral differences between predators and prey at the landscape scale during different phases of island-wide ecological restoration. This study will fill a fundamental gap in our knowledge of the evolutionary selective pressures on animal personality and contribute to our understanding of how animal personality traits can shape predator hunting and prey escape success, movement patterns, and landscape-scale ecosystem interactions.