Rhode Island State Mammal
Gray Seal (common name)
Halichoerus grypus (scientific name)
Gray seals live along the Canadian and U.S. east coast, mostly in the north but as far south as Virginia. They’re common in the New England area, particularly around Rhode Island. As seals go, gray seals are medium-sized, and differ from common seals by having a straight profile, more widely spaced nostrils, and fewer spots. The gray seal’s scientific name, Halichoerus grypus, means "hooked-nosed sea pig," and refers to its large, wide-set nostrils.
ALSO KNOWN AS
Grey seal, Atlantic grey seal, horsehead seal
In spite of its name, the gray seal’s color varies considerably. Females usually range from silvery gray to brown with darker spots and are generally lighter colored than males. Females’ coats are even lighter on their chests and on the undersides of their bodies. Male gray seals normally range from dark grayish brown to black, with pale patches and lighter scars around their necks. Most gray seals, particularly the males, have a noticeably long nose with wide nostrils, the animal’s most distinguishing feature.
Maximum 46 years for a female, 29 years for a male; average 35 years for a female, 25 years for a male.
Cool to cold coastal areas, including rocky coasts, unpopulated islands, and icebergs.
Range: Coastal Great Britain and Ireland, Faroe Islands, Iceland, the Baltic coast, coastal Canada, and south as far as Virginia, isolated populations on the French, Dutch, and German coasts.
Conservation: Least Concern (LC). The U.S. gray seal population is currently increasing. Until 1962, American populations were diminishing because of hunting. With the 1972 Marine Mammal Protection Act, populations began to rebound and are becoming more common in the southern part of their range.
In the U.S., gray seal pups are born in the winter on ice or land. At birth, they have soft white fur, but they shed this by the time they are a month old. Once their waterproof adult coat has grown in, they learn to fish and quickly become independent. Baby gray seals nurse for only 15 to 18 days, and less if they are born on ice, but they gain 2.5 to 4.5 lbs (1.2–2 kg) per day while they nurse. They lose weight again once they’re weaned, before they learn to fish for themselves.
Male gray seals mature at four to six years but usually start breeding when they are nine to 10 years old. They don’t normally come to land until after the first pups are born. In breeding season, males spend much of their time out of the water, and they go without eating. Some return to sea for a couple of days at a time, but others do not. Adult males stay on shore an average of 36 days, and as long as 57 days, so they lose a substantial amount of weight during breeding season. Male gray seals stay near a group of females but don’t define or defend a particular territory. Males often mate with up to 10 females, though in sparsely populated icy or sandy areas they may only be able to find one mate.
Females are mature when they are three to five years old. They come to shore shortly before giving birth and stay there, fasting, until their pups are weaned and they have mated, usually about three weeks. Mating can occur on land or ice or in water. Because they are lactating at the same time, they tend to lose more weight than males during the breeding and fasting period.
Gray seals tend to stay in a particular area throughout the year, though they can travel more than 65 miles (over 100 km) offshore for short periods to search for food when necessary. Seals searching for food usually look for gravel or coarse sand seabeds, the habitat of their favorite food, sand eels. Usually, though, they forage locally and make routine rounds to find food. Gray seals in the U.S. and Canada molt in May and June.
Top land speed recorded: 35 mph (56 kph)
Fish, sand eel, and skate are the most common sources of food. Diet varies by location, and individual gray seals can show strong preferences for a particular food. Less common food sources include crustaceans, mollusks, and even sea birds.
Breeding interval: Annual
Birthing period: January to February
Average litter size: 1 pup
Size at birth: 40 lbs (18 kg)
Click to enlarge an image
Data Source: U.S. Fish and Wildlife Service
Author: World Trade Press