The Weddell seal is the southernmost breeding mammal on Earth, spending the Antarctic winter under the sea ice. It has been studied for decades at sites such as McMurdo Sound, making it one of the best-known Antarctic mammals.
Interesting facts
- It breeds further south than any other mammal.
- Weddell seals make a remarkable range of underwater calls.
- Pups gain around 2 kg a day on rich milk.
- They are named after the British sealer James Weddell.
- Worn teeth from scraping ice can shorten their lives.
- They are relatively approachable on the ice.
Behaviour
Weddell seals spend much of their time under the ice, hunting in darkness. Males defend underwater territories around breathing holes during the breeding season.
Breeding and young
Pups are born on the ice in spring (September to November) and can swim within about two weeks.
Threats and conservation
Considered secure, but dependent on sea ice and on fish stocks affected by fishing and climate change.
Where to see it
- Antarctic Peninsula (expedition cruises)
- Ross Sea (specialist expeditions)
Status source: IUCN Red List. Profile last reviewed September 2026.
Where to see the weddell seal
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