In areas like southeast Alaska where new territory is available, groups of young males will usually leave to explore and move into new areas. The male otter will stay among the bachelors until he is ready to mate and defend a territory. Young females usually reach sexual maturity at age two or three and have their first pup when they're three or four. When prey is abundant and environmental conditions are good, young females can have a pup every year. This may explain why otters are able to increase their numbers so quickly in newly colonized areas with abundant food resources, such as southeast Alaska.
Sea otters are efficient predators, eating almost any invertebrate or fish they can find and catch.
In areas with rocky bottoms the preferred species are sea urchins and abalone. In areas with softer bottoms they eat clams and crabs. Biologists are unsure of how deep they are capable of diving but they are known to dive to greater than 300 feet and are able to stay down for up to five minutes. To search for its prey on the sea floor or within the kelp beds, the otter uses not only its eyes but its dexterous front paws and the sensitive whiskers on its face. In the dim light of the sea floor they must quickly dig out with their mitt-like paws the clams in the soft bottom, or feel along cracks in the rocks and under kelp for chitons or abalone, before they run out of air and have to return to the surface.