Gray seal

Halichoerus grypus

SUBFAMILY

Phocinae

TAXONOMY

Halichoerus grypus (Fabricius, 1791), "Greenland." OTHER COMMON NAMES

English: Horsehead seal, Atlantic seal, Atlantic gray seal, Baltic gray seal.

PHYSICAL CHARACTERISTICS

Males: 7.1 ft (2.3 m); 595 lb (271 kg); Females: 6.2 ft (2 m); 455 lb (207 kg). Males are noted for their large curved snout, which females do not have. Males generally have a dark pelage (black or charcoal gray) that is sometimes mottled with gray patterns; females generally have lighter gray pelage that is usually mottled with black patterns. Both show considerable variation. Pups are born with white lanugo.

DISTRIBUTION

Eastern and western North Atlantic Ocean, Baltic Sea. HABITAT

Breed on island beaches (sand, cobble, boulders) and on ice floes. Forage in waters ranging from 124 to 775 ft (40-250 m) deep.

BEHAVIOR

Breed in colonies of varying densities. Ice-breeding colonies are usually less dense. Individuals tend to return to the same breeding colony every year. Large molting groups form on islands during the spring and early summer.

FEEDING ECOLOGY AND DIET

Considerable individual variation in foraging strategy, ranging from migrating to a foraging ground, randomly searching and coming and going from a fixed resting place to a particular foraging patch. Primarily eat fish; the principal species eaten varies by location, but includes cod (Gadus morhua), capelin (Mallotus villosus), and sand eels (Ammodytes spp.).

REPRODUCTIVE BIOLOGY

Males are polygynous with the most successful males defending clusters of females, but other successful tactics involve mating opportunistically with departing females that have already mated. Males do not succeed in mating until age 12-15 years. Females produce a single pup annually beginning at about age four to six years. Lactation lasts about 17 days and pups are fed milk that is about 60% fat.

CONSERVATION STATUS

Not threatened. Populations are protected and growing at substantial rates of greater than 12% annually. In 2002, the largest breeding colony, Sable Island, Nova Scotia, produced 50,000 pups.

SIGNIFICANCE TO HUMANS

At one time they were hunted for their pelts and blubber (rendered into oil). They are no longer hunted and in some instances have become a nuisance to aquaculture and certain fisheries. ♦

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