Weddell Seal

So I’ve been thinking and I’m going to be trying to add something new to this blog, which will hopefully give you a reason to make those small changes in your life to help the planet and will also teach you a bit more about the plants and animals we share this world with.

I’m going to start these posts with an animal which some of you may not have heard of before but is being heavily affected by global climate change and the decreased amounts of ice found at the Antarctic ice caps.

The Weddell Seal, this seal is found in the Antarctic and like the Empire penguins remains there throughout the harsh winter storms in the darkness. In fact the Weddell Seal is the only mammal which remains on the Antarctic continent throughout the entire year. They have been seen in waters as far north as New Zealand and Australia but these sightings are extremely rare.

The Weddell Seal is perfectly adapted for its life in such an extreme environment as the Antarctic where surface temperatures can drop as low as -40°C and that isn’t accounting for wind chill. However the Weddell Seal doesn’t spend the majority of its time on the ice, it instead prefers the more sheltered environment of the world under the ice. Thanks to the insulation of the ice the liquid water under it remains at a fairly constant temperature of just above 0°C which makes surviving a lot easier.

They are capable of diving for well over 20 minutes and go to depths of 500+ meters. These deeper dives are usually undertaken in the day, while night dives usually bottom out at around 200 meters. Their underwater navigation is excellent which of course is necessary as they have to find their way between their breathing holes in the ice.

These holes are kept open throughout the coldest days and require constant work to stop them from icing over. To prevent this Weddell seals use their teeth to bite away at the developing ice crystals. This method is effective but also limits the seals lifespan as this constant use wears away the teeth and then the seals end up dying from starvation. The average life expectancy of the Weddell Seal is unknown with individuals living from 12 to 15 years while others live up to 40.

A seals diet is primarily made up from squid, fish and krill and some seals have even been observed blowing air bubbles into ice cracks in an attempt to flush prey out into open water where the seals manoeuvrability allows it to quickly and effectively catch the prey. They aren’t however on the top of their food chain and seals have to avoid being hunted by their natural predators which are leopard seals and killer whales which have developed their own hunting methods to make them efficient killers.

There are approximately 800,000 Weddell seals around the Antarctic

and they form up into large colonies around September and October to give birth to a single pup after a 9-10 month gestation period. It is then a race against time for the pup to gain weight to allow it to survive the extreme winter. After 6-8 weeks the pup is weaned and at that point they have gone from the starting weight of around 29kg to several times that weight. They continue to grow for the next 3 years till they reach a weight of 400-500kg. There is also a delay before they become sexual active and begin breeding, although they have reached maturity by 3 a Weddell Seal does not breed till it’s around 5 years old.

I hope this has taught you a few things that you didn’t know beforehand.

Thanks for reading