Antarctic Fur Seal foraging strategies
Geolocators have helped reveal the foraging strategies of fur seals during the Antarctic winter.
Our new paper published this week used a combination of geolocators and time-depth recorders to track the movements and dives of female seals from sub-Antarctic Marion Island in the Southern Indian Ocean.
During their 8 month winter foraging trips these relatively small animals (females weigh 30-40 kg) face a choice: stay close to the island but expend more energy diving deeper and longer to find food, or travel thousands of kilometres south towards the sea ice where prey such as krill is more accessible and can be reached with less diving effort.
Both of these strategies have their costs and benefits, including the energy expended during travelling and diving, the quality of prey available and even maintaining body temperature while pregnant in the stormy Southern Ocean in winter.
It appears that both strategies currently co-exist in the population because neither is clearly a better choice than the other. But with changes to the environment, we might see one strategy dominate.
Understanding the different strategies that exist among individual seals shows us that not all animals in the population will be affected equally by changes in the Southern Ocean environment.
The geolocators used in this study have been repurposed into wearable art through the Geolocation Journeys project. By donating to this research you can own your own geolocation creation and become apart of this Southern Ocean story. Donate here.
You can find the full paper here.