Commonly found swimming in ice-free northern waters, the harbor seal (Phoca vitulina) is one of the smaller seals. This species typically lives in saltwater bays and estuaries but also inhabits freshwater lakes and rivers. A harbor seal can be solitary, but sometimes joins groups along the shoreline. Seaside vacationers often see the bobbing heads of these seals in the water.

Harbor seals in Maine © Mark Wallner / Wing It Wildlife

In many pinniped species, males are much bigger and stronger than females. These assets help win fierce battles for group dominance. Harbor seal fights are less ferocious, and males are roughly the same size as females.

BEHAVIOR: Long Island Bound
Even in the winter, popular vacation spots along Long Island Sound teem with sunbathers and swimmers—in the form of seals! Harbor, harp, hooded, ringed and grey seals all journey south from their fair-weather breeding grounds to visit haul-out sites on Long Island and the surrounding islands. In May, most of the seals head north to bear pups and breed, but some stay year-round.