Seals
Seals are marine mammals found the world over. Characterised by their torpedo shape, seals are intelligent and playful animals. Antarctica is home to different seal species, each sharing a basic common lifestyle of searching out prey in the water but spending time on the ice to give birth and look after their pups.
Weddell seal
The Weddell seal’s claim to fame is that no other mammal lives further south. With a thick layer of blubber and short dense fur, this species of seal can swim in water with temperatures of -2ºC. Weddells can dive down to depths of 600 metres and have the ability to hold their breath for up to an hour, by collapsing their lungs.
Weddell seals have specially adapted teeth that they use to scrape the ice to create holes. The ability to find and maintain holes deep within the ice gives Weddell seals access to the water to feed, and for breathing when in the water. The downside of this adaptation is that life expectancy of the Weddell seal is limited by tooth wear.
Southern elephant seal
With males weighing up to 4 tonnes and having a pronounced nose, it is easy to see where the name elephant seal came from. Even females can grow to a remarkable 1 tonne weight, thanks to their diets of squid and fish, which they catch by diving up to 1,500 metres deep. They perform these amazing dives by slowing their heart rate to just a few beats a minute, allowing them to hold their breath for an hour.
Leopard seal
Sleek and streamlined, the leopard seal is built for speed. They also have strong jaws, which makes the leopard seal a fierce predator. And their prey? Pretty much anything that moves, from krill and fish, to penguins and even other seals. Even the odd human has had a close encounter with their sharp pointy canine teeth when a leopard seal has leaped onto the ice to grab at an unsuspecting person, mistaking them for a penguin.
A leopard seal
A leopard seal lying in the pack ice digesting its latest meal.
Crabeater seal
One could be forgiven for thinking that these seals might eat lot of crabs – in fact, the food of choice of these agile seals is krill. They have special teeth that act as a sieve, allowing them to filter krill from the water.
Crabeater seal teeth
Crabeater seals (Lobodon carcinophaga) have specially adapted teeth. The interlocking teeth act as a sieve, allowing them to filter krill from the water. Krill are a common type of zooplankton.
Ross seal
Compared to the other Antarctic seals, little is known about the Ross seal’s lifestyle. They live in hard to access areas of pack ice and seem to prefer solitary lifestyles. They have large eyes, which is believed to aid them in searching for prey under water such as krill and squid. When approached, they have a loud call, much like a siren to act as a warning.
Useful links
Find out about the Auckland volunteer group called the SOS (Seal Observation Squad) that helps the Department of Conservation by responding to call-outs from the public about distressed seals during seal haul out season. In this DOC blog article read how one volunteer took this volunteering opportunity beyond the coastline and into the classroom.
Check out these blog entries and some great photos of these seals:
The Cool Antarctica website has facts, photos and background information about these seals:
