Wildlife and Area
Fisherman's Wharf is busy with wildlife as well as people. Eagles, seabirds, otters and seals all make appearances from time to time. Click the photos below for information about each species.
Information and photos provided by Kelp Reef Adventures.
The mature Bald Eagle is a spectacular bird with a dark brown body and wings and a white head and tail. Females are larger than males, weighing from 10-14 pounds, and have a 6½- to 7-foot wingspan. Males usually weigh from 8-10 pounds and have a 6- to 6½-foot wingspan. Young eagles are brown, with varying degrees of white mottling. They do not reach full adult plumage until they are 4-6 years old. Bald Eagles may live up to 40 years.
The Bald Eagle is found only in North America, generally in coastal areas or near large inland lakes and rivers that have abundant fish and shores with large trees.
Bald Eagles eatlive fish that they snatch from the water and dead fish, especially spawned salmon, which they pick up from stream sides. They also eat ducks and other water birds as well as small mammals.
Once the Bald Eagle reaches maturity they pair for mating and tend to remain paired for life. Bald Eagles build large stick nests called eyries in tall trees or on cliffs. They continue to build up the eyries year after year until they are massive. After the eggs are laid in late winter to early Spring, both parents incubate the eggs for 34 to 36 days. The young do not start to fly until they are 10 to 12 weeks old, and the parents continue to feed and defend them for another 2 to 3 months.
Great Blue Heron
The largest heron in North America with a slate-gray body, chestnut and black accents, and very long legs and neck. In flight, it looks huge, with a six-foot wingspan, its neck bent, and its head held in toward its body. Adults sport a shaggy ruff at the base of their necks with a long black eyebrow that extends back to black plumes emerging from the head. Juveniles have a dark crown with no plumes or ruff, and a mottled neck.
Great Blue Herons inhabit saltwater and freshwater usually in sheltered, shallow bays and inlets, sloughs, marshes, wet meadows, shores of lakes, and rivers. From Canada south to Mexico and Florida, nesting colonies are typically found in mature forests, on islands, or near mudflats.
The Great Blue Heron have a variable diet, their adaptability enables them to winter farther north than most herons. Fish, amphibians, reptiles, invertebrates, small mammals, and even other birds are all potential prey. When foraging, they stand silently along the shore waiting for prey to come by, which they then strike with their bills. They will also stalk prey slowly and deliberately.
Great Blue Herons usually breed in colonies containing a few to several hundred pairs. Pair bonds only last for the nesting season, and adults form new bonds each year. In February the male chooses a nesting territory high up in a tree and gathers sticks for the female who fashions them into a platform nest lined with small twigs, bark, and conifer needles. Both parents incubate the 3-5 eggs for 25-29 days, and regurgitate food for their young. The young can first fly at about 60 days old, although they continue to return to the nest and are fed by the adults for another few weeks.
Many people can recognize a Canada Goose Branta canadensis by its characteristic black head, white cheek patches, and long black neck. The elongated the body ranges in colour from light pearl-grey to chestnut, and even blackish brown. They weigh up to 18 pounds with a wingspan as large as 6.5 feet. They can often be heard as they pass overhead in an irregular “V” formation since there is usually a steady chorus of honking.
Canada Geese are found throughout North America, except in the high Arctic and in the extreme southern parts of the United States and Mexico. You can find them on almost any type of wetland, from small ponds to large lakes and rivers. However, Canada Geese spend as much or more time on land as they do in water.
Unlike many waterfowl species that feed mainly in aquatic environments, Canada Geese feed mostly on land. In spring and summer, they mostly graze on the leaves of grassy plants, but they also eat a wide variety of leaves, flowers, stems, roots, seeds, and berries. The geese must consume large quantities of food to obtain the nutrients they need, and they frequently spend 12 hours a day or more feeding.
Canada Geese mate for life, they prefer low-lying areas with great expanses of wet grassy meadows. They often use the same nest every year, nesting in the same area where their parents nested. Goslings begin communicating with their parents while still in the egg. They stay with their parents for a full year, returning to the breeding grounds with them after their first winter.
North American River Otter
The North American river otter is a semi-aquatic mammal, with a long, streamlined body, short legs and a thick tapered tail. They have wide, rounded heads, small ears, and nostrils that can be closed underwater. Their soft, dense fur is dark brown to almost black and effectively insulates them in water. The throat and cheeks are usually a golden brown with thick, long and whiskers. The feet have claws and are completely webbed.
North American river otters are found anywhere there is a permanent food supply and easy access to water. They can live in freshwater and coastal marine habitats, including rivers, lakes, marshes, swamps, and estuaries. River otters can tolerate a variety of environments, including cold and warmer latitudes and high elevations. North American river otters seem to be sensitive to pollution and disappear from areas with polluted waters.
North American river otters eat mainly aquatic organisms such as amphibians, fish, turtles, crayfish, crabs, and other invertebrates. Occasionally birds, their eggs, small mammals, and aquatic plants are also eaten. The otter uses its long whiskers to detect organisms in the dark water and captures prey with its mouth. It eats immediately after capture, usually in the water, although larger prey is eaten on land.
Males and females do not associate except during the mating season. Males and females come together to breed in late winter or early spring. Gestation lasts two months, but the young may be born up to a year after mating because these otters employ delayed implantation of the fertilized egg in the uterus. Births occur from November to May, with a peak in March and April
Adult Double-crested Cormorants are blackish with iridescent green or purple gloss above, a yellow patch of skin at the base of their bills called a throat pouch. Juveniles are brown above, paler below, with varying amounts of white on neck, breast and belly. In breeding plumage, adults have two whitish tufts behind their eyes, hence the description 'double-crested.'
Found on both coastal and inland waters along the Pacific Coast from Alaska to Mexico, Cormorants are often seen perched on rocks, sandbars, or pilings near fishing sites. They forage at ponds, lakes, slow-moving rivers, estuaries, and open coastlines.
The Double-crested Cormorant is an opportunistic feeder, taking a variety of prey species from slow-moving or schooling species of fish, to occasionally consuming insects, crustaceans, and amphibians.
The male Cormorant chooses a nest site and brings nest materials to the female who does most of the building. The nest, a platform of sticks and debris, may be found on the ground on a rocky cliff near water. Both parents incubate the 3 to 4 eggs and feed regurgitated food to their young. After leaving the nest, the young roam the colony in groups called crèches and return to the nest site to be fed, they are completely independent at 10 weeks.
Steller Sea Lion
Steller or northern sea lions are sometimes confused with California sea lions, but are much larger and light tan to reddish brown in colour. Males may grow to 11 feet in length and weigh almost 2,500 pounds. Females are much smaller, and may grow to 9 feet in length and weigh 1,000 pounds. Stellers have a bulky build and a very thick neck, which resembles a lion's mane, hence the name "sea lion.” They have a blunt face and a boxy, bear-like head and lack the bump on the top of their heads (sagittal crest) as is seen in adult male California sea lions.
Stellers are found throughout the North Pacific Rim from Japan to central California. Unlike California sea lions, Stellers tend to remain off shore or haul out in unpopulated areas.
Steller sea lions eat a variety of fishes, invertebrates, and occasionally other pinnipeds. There is great need for concern about the population, which has dropped by 80% in the last 30 years. Researchers believe that a decline in the fish they eat is the biggest cause for this decline.
Pups are born on offshore islands from mid-May to mid-July, and weigh 35-50 pounds. Mothers stay with their pups for one to two weeks before leaving to hunt at sea. They then spend roughly equal amounts of time hunting and nursing pups on land. Pups usually nurse for a year, but some continue to nurse for up to three years.
Harbour seals have spotted coats in a variety of shades from silver-gray to black or dark brown. They reach 5 to 6 feet in length and weigh up to 300 pounds with males slightly larger than females. They have small flippers and are crawling seals that must move on land by flopping along on their bellies. In San Francisco Bay, many harbour seals are fully or partially reddish in colour. This may be caused by an accumulation of iron or selenium in the ocean or a change in the hair follicle.
Harbour seals are found north of the equator in both the Atlantic and Pacific Oceans. In the northeast Pacific, they range from Alaska to Baja California, Mexico. They favour near-shore coastal waters and are often seen at sandy beaches, mudflats, bays, and estuaries.
Harbour seals are opportunistic feeders, eating sole, flounder, sculpin, hake, cod, herring, octopus, and squid. They spend about half their time on land and half in water, sometimes sleeping in the water. They can dive to 1,500 feet for up to 40 minutes, although their average dive lasts three to seven minutes and is typically shallow.
Harbour seal pups are born in March and April and weigh about 30 pounds at birth. A pup can swim at birth, and will sometimes ride on its mother's back when tired. Pups make a bleating noise that sounds like "maaaa," and they are weaned after about four weeks. Adult females usually mate and give birth every year. They may live 25 to 30 years.