Foraging Behavior and Movement Patterns of the Leopard Seal in the Antarctic Peninsula

Daniel P Costa, University of California Santa Cruz, Santa Cruz, CA, United States, Sarah S Kienle, University of California Santa Cruz, Dept of Ecology and Evolutionary Biology, Santa Cruz, CA, United States, Stephen Trumble, Baylor University, Biology, Waco, TX, United States, Shane Kanatous, Colorado State University, Fort Collins, CO, United States, Michael E Goebel, National Marine Fisheries Service, Antarctic Marine Living Resources Division, La Jolla, United States and Daniel E. Crocker, Sonoma State University, Biology, Rohnert Park, CA, United States
The Antarctic Peninsula is one of the most rapidly changing habitats in the world. To better understand the ability of the leopard seal, an apex predator in the Antarctic ecosystem, to cope with a changing environment, we examined the foraging behavior and habitat utilization of leopard seals using satellite telemetry. We deployed 12 satellite-linked tracking devices on 3 adult males, 8 adult females, and one juvenile female leopard seal on Cape Shirreff Livingston Island, Antarctica during April-May 2018. The animals ranged from 147 to 540 kg with a mean mass of 389 ± 95 kg. Three of the twelve leopard seals remained within the South Shetland Islands, while two female seals transited well to the northeast, with one stopping at South Georgia Island. On average leopard seals made short shallow dives with a mean depth of 28 ± 7 sd meters and a duration of 3.8 ± 0.5 sd min. However, they occasionally made deep dives, with the single deepest dive being to 428 m and lasting 10.1 minutes. Their physiological parameters were consistent with a shallow aerobic diver, with a blood volume of 134 ± 5.2 sd ml/kg. Their hematocrit ranged from 44 – 56 with a mean of 51 ± 4 sd. We determined myoglobin concentrations in the locomotor muscles 6 of the animals and those ranged between 44.9 ± 1.4 se mg/gr for Longissimus dorsi and 32.9 ± 0.8 se for pectoralis muscle. Information on their habitat requirements can be used to predict how their habitat might shift as the climate changes.