IOS RAPID: Does adaptation to urbanization promote resilience during a natural disaster? A test of brown anole (Anolis sagrei) behavior and stress after Hurricane Irma.

Rollins College, Winter Park FL

Investigators

Abstract

Non-technical Abstract Resilience is the capacity for individuals to cope with stressful challenges and recover successfully from any adverse effects of said challenges. Such challenges are met with a physiological response that involves the secretion of stress hormones into the blood and their accumulation in the brain resulting in the expression of adaptive behaviors, such as fight or flight. Individuals frequently exposed to stress in day-to-day life are predicted to recover more rapidly both behaviorally and physiologically, e.g., they are more resilient. Scientists have recently documented that anole lizards in urban Orlando have a lessened stress response when compared to rural counterparts, possibly as a means to cope with the challenges of urbanization, which could increase their resilience to stressful events. Hurricane Irma provides an unprecedented opportunity to test this "urban resilience" hypothesis by comparing how urban and rural populations perceived, responded and recovered from this natural disaster. Using data collected prior to hurricane landfall, this work will investigate stress hormones and their accumulation in the brain, and stress-related behaviors in both urban and rural lizard populations as they recover from the hurricane's impact. Understanding resilience in this context is valuable to conservation managers concerned about how natural disasters impact wildlife and potentially facilitate non-native animal invasions, such as the famed South Florida python invasion following Hurricane Andrew in 1992, which typically begin in cities. Conceptually this study can also inform how low resilience leaves individuals susceptible to the prolonged effects of extreme stress, such as occurs with post-traumatic stress disorder. This work will involve undergraduate students in data collection and analysis and provide opportunities for presentation of findings at national and international conferences. Technical Abstract Enduring natural disasters requires resilience, the ability to successfully cope with and recover from the adverse effects of extreme challenges. Prominent in resilience is the ability to successfully manage the stress response, a hormonal cascade initiating in the brain and ultimately involving the secretion of glucocorticoids from the adrenal gland. Glucocorticoids alter metabolism and behavior to permit survival during stress and frequent activation of this response can attenuate their secretion to avoid the cost of excessive accumulation which could negatively impact neural function. Preliminary data show urban populations of the invasive brown anole (Anolis sagrei) have an attenuated stress response compared to rural ones suggesting urban lizards may exhibit greater resilience. An unprecedented opportunity to test this "urban resilience" hypothesis occurred when Hurricane Irma made landfall. This research will provide undergraduate student opportunities to conduct research on circulating and neural glucocorticoid levels and stress-related behaviors in urban and rural lizard populations sampled immediately before and after Hurricane Irma to determine the time taken to return to "baseline" conditions prior to landfall. Understanding resilience in this context informs conservation managers interested in how hurricanes can promote accidental invasions of exotic species, such as happened with Burmese pythons after Hurricane Andrew in 1992. Such invasions usually start in cities, where potential invaders must simultaneously cope with both city and disaster associated stressors, yet this interaction has never been explored. Data from this study can be used to inform disorders characterized by low resistance to extreme stress, such as post-traumatic stress disorder.