The first research using GPS tracking of the movements of breeding snow petrels in Dronning Maud Land, Antarctica, has been published by the ANTSIE team in Marine Biology. The work was led by PhD student Eleanor Maedhbh (Ellie) Honan, supervised by Professor Erin McClymont, Professor Richard Phillips and Dr Ewan Wakefield, funded by the European Research Council and Leverhulme Trust.
GPS tracking was used to uncover how the snow petrels used their environment during early chick-rearing during the austral summer (December 2021-February 2022). The chick-rearing period is when the eggs have hatched and the chicks are independent enough to be left unattended at the nest, so that the parents can make the ~200 km journey out to the edge of the Antarctic continent to forage in the Southern Ocean. Snow petrels were tracked from two colonies around 700 kilometres apart: Ellie and her field partner Steph Prince were based at the Usteinen colony, working out of Princess Elisabeth Station and supported by the International Polar Foundation, and Ewan Wakefield worked out of Tør Field Station, tracking birds from the Svarthamaren colony, supported by the Norwegian Polar Institute.
The specially designed GPS-devices worn by the snow petrels recorded their location every thirty minutes during their foraging trips. When they returned to the colony, the location data from the GPS devices automatically downloaded to base stations placed nearby, Recovering the data from the base stations could be extremely challenge during harsh weather conditions, with strong winds and temperatures down to the minus thirties!
Snow petrel foraging is known to be closely associated with Antarctic sea ice, but a challenge for the team in this study was that the season in which they were working was marked by record-breaking sea-ice loss and severe (even by Antarctic standards!) weather in the region (see our previous report) . Once the data was downloaded, the movements of the snow petrels after they left colony were revealed. Despite being relatively small (snow petrels weigh less than 400 kg!) they travelled hundreds of km from their colony, to find the food to feed their chicks.
The Honan et al. study found that snow petrels from both colonies reached a maximum distance of around 395 km from their colony during their foraging trips. Figures like this are important for the wider ANTSIE project’s goal of using the stomach-oil deposits from snow petrel colonies to better understand past sea-ice dynamics. The study also uncovered subtle but important differences in how the sexes used the environment. Males tended to forage in areas with more sea ice and over the continental shelf, while females favoured foraging over deeper, more open ocean waters.
Notably, snow petrels were found to forage even in areas with little or no sea ice. This may reflect the birds’ response to the unusually low sea-ice conditions in 2022 and suggests that although snow petrels are considered ice-dependent, they may have some capacity to adjust their behaviour as the environment changes.
This study offers valuable insights into how an Antarctic top predator copes with environmental extremes. As climate change continues to reduce sea ice and reshape ecosystems across the Southern Ocean, understanding how species like the snow petrel respond is crucial. Their ability (or inability) to adapt could have cascading effects throughout the polar food web. These findings highlight both the vulnerability and resilience of wildlife in a rapidly changing world.