Environmental change across time and space is a universal and fundamental characteristic of ecosystems. To exploit the seasonal change of an environment, organisms must match the fluctuating opportunities with adaptive movement and feeding behaviors. Nowhere is this matching more important that in the Arctic, and nowhere is it growing more difficult due to climate change. Using Four Horn (Myoxocephalus quadricornis) and Slimy Sculpin (Cottus cognatus) as model species, we investigated the seasonal adaptations of an Arctic resident in Tremblay Sound, Nunavut, Canada. We used acoustic telemetry to track movements among seasons. These movements were paired with diet analyses during a summer resource pulse. Together, these methods suggest strong adaptiveness by sculpin to the seasonal change of the Canadian high Arctic. Despite residency, seasonal movements by sculpin indicate a phenological response of increased movement for feeding. Average home range area was seen to double in the summer indicating the expansion of foraging habitat caused by the increased opportunities brought about by the ice-off. This is corroborated by diet collections that were shown to be above expected distributions for both intensity and frequency. Intense feeding was shown with relative consumption (g diet/g fish) levels regularly exceeding 10%. Content analysis by NMDS indicates a strong seasonal shift in diet composition reflecting the progression of the resource pulse. Date alone was shown to explain 35.7% of all variation in the ordination of diet composition, with an increasing reliance upon larval fish and other open-water zooplankton to the diet. Ultimately, this research suggests a strong sensitivity to phenology is exhibited by species traditionally thought to be robust to change. This has implications for evaluating the persistence of species and behaviors within a context of anthropogenic climate change exacerbating phenological mismatch, especially in the Arctic.
