The seal family includes eighteen species that are spread out across the globe. Most species live in the Arctic or the Antarctic, but there are also species that live in more temperate coastal waters. They spend most of their time in the water, only hauling out to rest, mate and birth pups.

True seals do not have pinna, or external ears. They have a short neck and limbs, and relatively long bodies. Their hind flippers are shorter than those of the other members of the Pinnipedia family, and cannot be folded underneath the body to walk on. This makes phocids less agile on land. Most seal species have little difference between the males and females, though some do display sexual dimorphism in their size or colouration.

Most seal species live a solitary lifestyle, spending the bulk of their time hunting and swimming. During mating season this changes, however, because then the animals congregate in large numbers to birth pups and mate. When mating season is over, the seals moult together, after which they each go their separate ways. Phocid pregnancies typically last eleven months, and after a short nursing period, the mother will mate again.

A seal only cares for her offspring for a very short period. Depending on the species, seal pups can be nursed anywhere from a week to a month, during which they are quickly plumped up by the mothers’ incredibly fatty milk. The mother seal doesn’t eat a lot during this period, because she needs to spend most of her time and energy on feeding her pup. After the pup has gained roughly three times its birth weight, the mother promptly abandons her pup so she can mate and start the cycle again. The abandoned seal pup then needs to teach itself how to swim and hunt, because its mother will have taught it next to nothing.

Seals will usually reach sexual maturity when they are between five and six years old, but that can vary with each species. The maximum age a seal can reach depends on a number of factors, but will usually be between 25 to 30 years.

Foto: Seehundstation Friederichskoop