There is one defining feature of a raft of sea otters: the pink nose pads that stick out from their black, wet noses. It is the cheeky way a female otter can tell you she has just been mating.
When a male otter bites down onto a female’s nose, her nose pad becomes swollen and bloody. As a result, she can have pink scars on her nose pad from the injury.
During mating, a male holds the nose of the female in close proximity to his jaws. This behavior, which occurs during estrus, results in many females having nose scars.
Observations of female sea otters show that they often enter estrus and become pregnant in three days or less, depending on the individual and geographic variation. During this time, they form pair bonds and engage in playful and sometimes aggressive behaviors.
They may mate repeatedly during the duration of estrus. When the mating is complete, the couple swims together until the male releases the female.
The birth rate of otters varies, but is generally about one per year in most areas. Pups weigh up to five pounds and are born in the water with their eyes open, and are dependent on their mothers for up to a year.
Because otters mate for life, it is difficult to estimate the overall population size of this species. However, otters are common in the ocean and can be found in coastal and offshore waters throughout North America and Japan.