Meeting Abstract
The adaptive nature of invasive species is becoming recognized as facilitating their survival in conditions that differ from their native range. Behavioral changes in invasive populations have been poorly explored but offer a wide potential when combined with physiological traits. For anurans invading xeric habitats, the importance of finding water is relevant for reproduction, to maintain hydration to function optimally and not experience dehydration stress. The water-finding hypothesis (WFH) states that survival can be enhanced through the behavioral ability to find water. We tested the WFH in Sclerophrys gutturalis from their native population in Durban and an invasive population in Cape Town Additionally, we tested if artificially elevated levels of corticosterone (CORT), which is known to increase during dehydration stress, affect water-finding behaviors. In a labyrinth experiment, we observed the toads’ ability to find water in different hydration states (100%, 90% and 80%). We found that individuals from the invasive population took longer to engage in water-searching behavior and spent more time near to the water source after finding it. Also, toads from the invasive population were more active and at 90% dehydration they show higher number of attempts to find water. Moreover, elevation of CORT in fully hydrated toads increased the success of finding water. Our experiment suggests that rapid adaptative water-finding behavior might facilitates survival of an invasive anuran in a xeric habitat. Additionally, we suggest a link between elevated CORT levels and water finding success. Our results lend support to the importance of adaptive behavior in successful invasions and the modulation of water-finding behavior by CORT.
