Meeting Abstract
Little is known about the fine-scale temperature variations of the coastal landscape, which limits our ability to assess its effect on animal productivity. In 2018, we studied the effects of the thermal landscape on the least tern (Sternula antillarum), in a breeding colony on Lea-Hutaff Island, NC. Our three hypotheses are: (1) the thermal landscape, as measured by thermal imaging, will be highly variable and will reflect ambient environmental conditions. (2) The thermal landscape, as measured from thermal images, influences nest-site selection by least terns. Specifically, we predict that birds avoid nesting in the hottest locations. (3) The thermal landscape, as measured from thermal images, limits nest success for least terns. We predict lower nest success for nests in the hottest locations. We monitored 157 nests. Nest success was determined by successful hatching of chicks. We recorded surface temperatures via a fixed-wing mapping unoccupied aerial vehicle (UAV). We launched the UAV ~250 m away from the colony and maintained an altitude of 122 m to minimize bird disturbance. The UAV carried a thermoMAP thermal camera with a temperature resolution of 0.1°C. At the study location, we recorded ambient environmental conditions at ground-level throughout the season. The weather data will help determine which variables influence sand surface temperature and explore the cause of nest success. Our preliminary results indicate that there is a wide range of temperatures across the landscape, supporting hypothesis 1. Tern nest locations varied in surface temperature. Nest success decreased in nests incubated in hotter locations and during a weeklong heat wave, providing tentative support for hypothesis 3.
