Meeting Abstract
Seabirds are marine top predators often studied as bioindicators of climate shifts. Though many studies have analyzed the effect of macroclimatic variation on marine prey species availability and thus seabirds, few have analyzed effects of microclimate – fine spatial patterns of climate. We tested the hypothesis that localized temperature, humidity, and light at nests interact with food availability to alter black-legged kittiwake (Rissa tridactyla) chick developmental physiology, quantified via cloacal temperature measurements and growth rates, and reproductive success. We recorded temperature, humidity, and light exposure at individual nest sites during egg laying and chick rearing (May-August 2017) on Middleton Island, AK. Nests were located on “panels” with distinct compass orientation, insolation, and exposure to wind and rain. Panels housed ~25 nests, alternating between supplementally fed and unfed panels. 2017 microclimate data were compared to historical climate records and reproductive success from the same nest sites. Microclimate varied across the tower, with highest light exposure on the western face and lowest on the north. Humidity and temperature were inversely related, while light and temperature were positively related. Unexpectedly, nests at fed panels maintained higher average temperatures than adjacent unfed panels, suggesting variation in metabolism may influence nest microclimate. While food availability had a greater impact on growth and reproductive success, the data suggest microclimate may explain some variation in reproductive success. These data demonstrate another mode by which changes in climate may affect populations by altering individual physiology.
