A new study identifies leopard seal births and pups in the first database of its kind and reveals evidence that these sightings are not limited to the Antarctic.
Leopard seals had always been considered an Antarctic species, residing predominantly within the pack ice. Births were always thought to occur on the ice flows surrounding the continent. However, this study reveals this is simply not the case. Leopard seals were found to be birthing their young in multiple regions throughout the Southern Hemisphere.
After discovering three birth records in New Zealand, a team of New Zealand scientists worked in collaboration with others from around the globe to build the world’s first leopard seal birth and pup sightings database.
Lead author Dr Krista van der Linde from WWF-New Zealand, the University of Canterbury, and LeopardSeals.org noted that, “Despite their ecological importance as a top order marine predator, little is actually known about them giving birth or their early life stages as a pup. In fact, we had no idea how many birth and pup records existed. Originally we aimed to document three births which occurred in New Zealand waters but then the study expanded to include sightings elsewhere. While we expected to find birth and pup records from Antarctica, the extent of birth and pup sighting records from outside of that region has come as quite a big surprise.”
Leopard seal birth and pup sightings were documented in the Antarctic, the sub-Antarctic Islands, Chile, the Falkland Islands, New Zealand and Australia. Additionally, the birth and pup sighting records show leopard seals do not just give birth on the Antarctic pack ice, as had previously been the assumed ‘norm’, but that they are in fact regularly giving birth on land much further north.
Dr Ingrid Visser, also from the University of Canterbury and LeopardSeals.org stated, “We were intrigued to find that approximately 84% of birth records and 54% of the pup records occurred in places other than Antarctica.”
Rick Bout from LeopardSeals.org says, “This study is instrumental in identifying the importance of northern regions to the leopard seals range. We can’t just look to protect their populations in one area, because we have clearly shown that many areas beyond their traditional ‘core range’ are potentially important to their reproduction.”
This study was a collaboration between the British Antarctic Survey UK, Department of Conservation NZ, LeopardSeals.org NZ, National Antarctic Scientific Center of Ukraine, National Marine Fisheries Service USA, Orca Research Trust NZ, Oregon State University USA, Universidad de Valparaíso Chile, University of Canterbury NZ, University of Minnesota USA and WWF-New Zealand.