Illustration © Pieter Folkens
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Distribution/Migration: North Pacific. Breed and winter in Mexico and migrate north through coastal waters (passing through Unimak Pass) to summer feeding grounds in the Gulf of Alaska and Bering, Chukchi, and Beaufort seas. Return south in fall. Pink shows summer range, blue lines show migration routes, purple shows year-round.
This web page is modified from the book Marine Mammals of Alaska by Kate Wynne, illustrated by Pieter Folkens, available at the Alaska Sea Grant Bookstore.
SIZE: Average adult 46 ft (14 m), 33 tons. At birth 15 ft (4.5 m), 1100 lbs.
BODY: Body robust. Head profile triangular, upper jaw relatively narrow and arched with up to 180 (to 7 in. long, or 0.2 m) yellow baleen plates per side. Patches of skin encrusted with barnacles. 2–7 short throat creases. Flippers paddle-like and pointed. Flukes broad.
COLOR: Mottled gray, some orange patches caused by parasitic whale lice.
DORSAL FIN: No dorsal fin, but a low hump followed by several “knuckles” on dorsal ridge of tail stock.
BLOW: Heart-shaped, to 10 ft (3 m) high.
BEHAVIOR: Group size usually 2–3 with large aggregations on feeding and breeding grounds. Breaching and lobtailing common.
DIVE PATTERN: Blow 4–6 times per min between dives of 3–5 min. Usually raise flukes before a prolonged dive.
HABITAT: Coastal, shallow waters over continental shelf.
FOOD HABITS: Only benthic-feeding whale: dredge through mud and use baleen to filter out bottom-dwelling amphipods and crustaceans. Often seen surfacing with mud streaming from mouth. Rarely feed on breeding grounds.
LIFE HISTORY: Sexually mature at 8 yrs. Breed in November-December during southern migration. Single calf every 2 yrs born January–February in lagoons of Baja California after gestation of 13.5 mos. Lactation lasts 7–9 mos.
STATUS AND HUMAN INTERACTIONS: Approx 21,000 in the east Pacific. Commercially harvested until 1947. Current annual subsistence harvest of 120–140 by Native Alaskan and Siberian hunters. Heavy whale-watching and tourist traffic on migration and calving grounds pose collision risk.