Bay Area Birders Guide to Mammals in the Nearshore Water
Animals you may spot from shore.
Gray Whale (Eschrichtius robustus)
Up to 50 feet long, 36 tons. Dorsal ridge but no fin. Mottled gray in color. Migrate south past California in December and January. Northward migration from February through May with mothers and new calves coming last.
Humpback Whale (Megaptera novaeangliae)
Up to 50 feet long, 65 tons. Small dorsal fin far back from head. Enormous front flippers and knobby back. Migrates south along Bay Area coast in September.
Northern Elephant Seal (Mirounga angustirostris)
Up to 20 feet, 4 tons. Bulls have drooping proboscis. Furrowed skin, mostly dark gray in adults. On isolated beaches at Point Reyes and Año Nuevo, especially during winter breeding season.
North Pacific Pilot Whale (Globicephala scammoni)
Up to 22 feet. Melon bulge on forehead, hooked dorsal on all blackish body. Often in pods of 200. Slow swimmers and fearless around boats.
California Sea Lion (Zalophus californianus)
Up to 8 feet, 600 pounds. Common in shallow waters. Has jointed flipper, often surfs on waves. Has staccato bark. Dark brown and males have crest on head. Often loafing onshore. Breed in June and July.
Common Dolphin (Delphinus delphis)
Up to 8 feet. Convex-fronted dorsal fin, strong beak as in all dolphins.Dark back, light underneath. Can be found in groups of 1,000 or more. Cosmopolitan. Common in classical Greek art. Attracted to boats and often leaps out of water.
Dall's Porpoise (Phocoenoides dalli)
Up to 7 feet, 200 lb. Uncommon, white on top of hooked dorsal fin. White oval on its side. Small pods mostly in nearshore waters. Blunt porpoise snout.
Harbor Porpoise (Phocoena phocoena)
Up to 6 feet, 160 lb. Small, blunt dorsal fin. Blunt snout. Blackish upper parts, pale belly. Usually in small pods. Quite common nearshore, may enter Bay.
Pacific Bottle-nosed Dolphin (Tursiops gillii)
Up to 12 feet. Conspicuous beak and overall dull gray color with no obvious streaks or splotches. Usually in small groups, mixes with other cetaceans. Enjoys following boats. "Flipper" belonged to this species.
Pacific White-sided Dolphin (Lagenorhynchus obliquidens)
Up to 7 feet. Travels in large schools. Hooked dorsal fin and white line along each side of dark back. White oval patch on front half of body. Blunt beak. Often follow boats and show synchronization of movement.
Steller's sea lion (Eumetopias jubata)
Up to 10 feet, one ton. Colony breeds at Año Nuevo. Uncommon in Bay Area, avoids bays and estuaries. Cream to yellowish-brown color. Jointed front flipper.
Harbor Seal (Phoca vitulina)
Up to 6 feet, 250 pounds. Often seen as conical gray nose and round head sticking above ocean surface. Sausage-shaped, no jointed flipper so clumsy on land. Abundant in Bolinas Lagoon. Color: silver to gray with dark splotches. Often curious about bipeds on land.
Sea Otter (Enhydra lutris)
Up to 5 feet, including tail. No other sea mammal in Bay Area has a tail. Dark brown, often floats on its back. Sea otter abundant in Monterey, uncommon north of Santa Cruz. The otters seen around Point Reyes and Tomales Bay are River Otters.
Surfer (Homo natiturio)
Up to 6 feet, often attached to oval board; 250 pounds. Usually covered in black neoprene, may have bright colored markings. Small rounded head, no dorsal fin. Common along coastline, often in dense pods. Strictly diurnal.