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Weddell seals
Newborns have a full set of adult teeth
- Weddell seals are the most southerly breeding of all the mammals.
- Because they are air-breathing furry mammals, seals have to give birth on land (or ice). Seals can’t give birth in the water like dolphins can because (a) the baby would drown, and (b) the baby’s fur is only efficient as an insulator if it has a layer of air trapped under it, which it couldn’t get if it was born underwater.
- Mating is mid Nov and Dec (summer), just after last year’s pup has been weaned.
- There is delayed implantation (fertilised egg doesn’t embed in womb straight away) and then a 9 to 10 month gestation from Jan/Feb onwards. (So total length of pregnancy is 11 months).
- One baby is born in the spring (Sept to October). Very rarely twins are born.
- The newborn is 29kg in weight.
- Newborns have a full set of adult teeth.
- Mum stays with the baby full time to begin with, living off her fat reserves. Her fat is also being pumped into her milk. She will lose a lot of weight because of this demand on her fat reserves.
- Weddell seal milk is about 54% to 60% fat. (Cow milk is 4% fat). It also has 10% protein and very low sugar content.
- The pup is weaned at about 5 to 6 weeks old, in early to mid December. It will weigh about 110kg at this point.
- The pup then goes off on its own to perfect its foraging skills.
- Pups are fully grown when 3 years old.
- Females are sexually mature at 3-6 years old, males at 6-8 years old.
Weddell seal winter boot camp
A Weddell seal mum has 6 weeks to teach her pup all he needs to know to go it alone.
