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Southern Elephant Seals and Crabeater Seals

1/ What are elephant seals like?


Elephant seals are the largest of all seals.   Males can grow to 4.5m long (15ft) and weigh up to 4 tonnes (8800lb). Like fur seals, they show a strong sexual dimorphism (difference in size between the males and females), females grow to about 2.8m (9ft) and 900kg (2000lb). A fully grown male and female side by side are commonly mistaken for an adult and juvenile.
They are called elephant seals partly because of their size and also partly because of the males snout or trunk that he inflates to impress and intimidate rivals when competing with other males.
This picture is of a male who has sustained damage to his trunk during a fight. This makes him less able to compete with rival males and so he was master of a very small harem of 2 or 3 females rather than up to a hundred that the biggest and strongest males can command.

2/ What are these seals doing?
When ashore and not competing with each other and when they don't have pups, elephant seals gather in groups called "pods". Pods are extremely smelly places! If the wind is towards you, you know you are coming up to an elephant seal pod long before you see it!
A diet largely consisting of squid that is caught during feeding dives usually of 200 - 400m but sometimes up to 1500m doesn't do anything for the digestive system or your breath!
Most of the time pods are quite fairly restful places in a constant snoring and guttural noise sort of way, but every now and then one of the inner most seals decides it wants to go to sea. Two tonnes or more of seal lumbering across his sleeping companions causes quite a commotion.
Elephant seals spend only a small amount of their time on land. Ashore they are cumbersome and great lumbering beasts, in the water like many aquatic animals, they become lithe and graceful with the blubber that made them ungainly on land becoming essential as insulation.



3/ What are young elephant seals like?
Elephant seal pups are born in the Antarctic spring. Like many Antarctic seal pups, they stay with their mother increasing rapidly in weight while the mother gets progressively thinner. Eventually the mother has to feed and teach the pup, by which time the pup is quite large and well developed. The pups are very dark at birth and have quite delicate flippers with long elegant nails that they scratch themselves with quite precisely.
Weddell seal pups are like big mobile unstuffed pyjama cases with the personality of a reckless 5 year old. Fur seal pups are like small terrier puppies, bouncy and bold. Elephant seal pups on the other hand are like little old men, very precise and somewhat gnome-like, a stage that they grow out quite rapidly as they become teenagers (in elephant seal years that is).

4/ How friendly are Elephant seals?
Antarctic seals are generally completely unafraid of man despite the inglorious days of sealing when hundreds of thousands of them were killed fir their fur and/or blubber.
These days the recommendation is to stay considerably further away than this, the small weaned pup in the foreground has just his very close-fitting personal space invaded is isn't that happy - he's not actually that bothered either to be honest. The larger and older seals nearby seem completely unflustered.
The only time these seals get very upset is if you approach them walking upright and normally. When they threaten each other, they rear upwards to get as much height as they can and so seem to assume that an upright figure is a threat. If you get down low as this guy has done, they are pretty much unfrazzled, though by that time you may be uncomfortably close to a ton or more of smelly, sharp-toothed animated blubber.

5/ What kind of seals are these?
These are crabeater seals, probably the most numerous large mammals on earth after humans.These are resting on a large ice floe floating in broken summer ice near the Antarctic peninsula. Though they are so numerous, it is unusual to see many crabeater seals together as they live almost their entire lives on and amongst floating ice. For this reason also, it is difficult to estimate their numbers, but by 2000 there were thought to be about 50 million.
Crabeaters are large seals of about 220kg (484lb). They are frequently scarred, sometimes quite badly by predatory leopard seals or killer whales.
Crabeaters are fairly solitary, and the males and females are about the same size as the males do not need to be large to compete for a harem of females as in elephant and fur seals.
The female gives birth on an ice floe around September and suckles the young from a birth weight of about 20kg (44lb) to 110kg (242lb) at weaning, this takes around a month. As with other Antarctic seals, the female comes into oestrous very quickly and an attendant male will mate with a female, seeing others off. After mating the male leaves the female and goes to find another receptive female that he can mate with.
Many seals give the impression that they form cosy family groups as they lay around together. The reality is usually that it is a mixed group of individuals with no real bonds other than between mothers and their own pups.

6/ Crabeater seals (Lobodon carcinophagus) on ice floe
Female Crabeater seals give birth on an ice floe around September and suckles the young from a birth weight of about 20kg (44lb) to 110kg (242lb) at weaning, this takes around a month. As with other Antarctic seals, the female comes into oestrous very quickly and an attendant male will mate with a female, seeing others off. After mating the male leaves the female and goes to find another receptive female that he can mate with.
Many seals give the impression that they form cozy family groups as they lay around together. The reality is usually that it is a mixed group of individuals with no real bonds other than mothers and their pups.
Don't they have some of the best scenery to look at though?!

7/ Crabeater seals (Lobodon carcinophagus) on ice floe
Crabeater seals on an ice floe. Crabeaters are the most timid of the commonly encountered Antarctic seals, whereas most types of Antarctic seal will lay there pretty much oblivious to what's going on around them, crabeaters tend to be more alert and are less easy to approach even if on an ice floe, they will quickly display signs of nervousness and are inclined to slip into the water and swim away.
Crabeaters often have scars on their bodies from close encounters with either leopard seals or killer whales.
8/  Do crabeater seals eat crabs?
Crabeater seals probably got their name because of a mistake by the early sealers who went down to the Antarctic. They actually eat krill, the staple diet of much of Antarctica's bird and mammal population. In fact there are no crabs at all in Antarctic waters, nor any other Decapod Crustaceans such as lobsters. No crabs live south of the Antarctic Convergence.
Crabeater seals are uniquely adapted amongst seals in that their teeth are adapted to form a sieve in a similar manner to the baleen plates of the great whales. They take a mouthful of seawater and krill and expel the water through gaps in their teeth while the parts that overlap prevent the krill from escaping.
Each seal consumes about 20kg of krill per day, and a quick bit of maths calculates that between them, crabeaters eat 1 million tonnes of krill per day! That's an awful lot of little shrimps!
Crabeater seals are circumpolar living all around the edge of the Antarctic continent.

9/ A Leopard seal
Leopard seal Named for the spotting on its underside, the Leopard Seal is one of the largest predators in Antarctica, smaller only than the killer whale. Females are larger than males and average about 3m (10ft) long and around 350kg (770lb). They appear more squat when on the surface as in this picture on an ice floe, where they are nearly always seen, only rarely coming ashore onto land. In the sea, they appear longer, sleeker and almost snake-like in form and movements, though they swim of course with fore and hind flippers.Leopard seals are built for speed, they have a large powerful head, a huge gape and a massive lower jaw. They frequent the edge of the pack ice and in particular areas around penguin rookeries all around Antarctica. They are fairly opportunistic as predators and will east a wide variety of prey from krill to penguins to young crabeater seals - their main prey. Their teeth are very much those of a carnivore, though they are also partly adapted with three large cusps on the pre-molars and molars that interlock and are also able to act as a strainer when feeding on krill.
They are inquisitive and fearless, frequently approaching small boats to investigate when their large "grin" and all of those teeth they have can make them appear quite menacing.
Their way of dealing with penguins is quite gruesome. Once caught and killed, the penguin is shaken violently from side to side by the leopard seal until it is literally thrown out of its skin and feathers for the seal to then swallow. Floating penguin skins in the sea are a sure sign of leopard seals nearby.
 
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