What are Seabirds, Shorebirds and Waterfowl?
Gulls wheel gracefully in the wind, sandpipers scurry on toothpick legs, Great Blue Herons patiently stalk the shallows, Canada Geese honk overhead in V-formations. These and other birds are integral to the beauty of shoreline environments. There are so many different kinds of birds, it’s difficult to make generalizations. There are divers, dabblers, Oystercatchers, mud flat foragers, even surfers. Nevertheless, they can be generally grouped so that we may make some useful observations about their activities.
Seabirds generally live, feed and breed either partially or wholly at sea. They often have long wings and may be graceful flyers or divers. Examples include gulls, cormorants and loons.
Shorebirds often feed and migrate along shorelines, but also live in inland areas such as wetlands, lakes and tundra. They are generally characterized by long legs, long bills and streamlined bodies. Examples include plovers, oystercatchers and sandpipers.
Waterfowl have strong, scaly legs and webbed feet, and live and feed in fresh and/or salt water. They have rounded, buoyant bodies and relatively long necks. This group includes ducks, geese and swans. (Diving ducks may be considered either seabirds or waterfowl.)
What kinds of birds frequent the harbours in the Victoria area?
Some of the resident and migratory birds that are commonly seen in the urban harbours of Victoria are listed below. Those marked with an asterix (*) are resident throughout the year. Many of these species are migratory, and arrive at different times of the year.
- Loons and Grebes: Red-throated Loon; Pacific Loon; Common Loon; Yellow-billed Loon; Pied-billed Grebe; Eared Grebe; Horned Grebe; Red-necked Grebe; Western Grebe.
- Cormorants: Double-crested Cormorant*; Pelagic Cormorant*; Brandt’s Cormorant*.
- Herons: Great Blue Heron*
- Swans, Geese and Dabbling Ducks: Trumpeter Swan; Mute Swan* (exotic species); Brant Goose; Canada Goose*; Wood Duck; Green-winged Teal; Mallard*; Northern Pintail; Gadwall; Eurasian Wigeon; American Wigeon.
- Diving Ducks: Canvasback; Greater Scaup; Lesser Scaup; Harlequin Duck*; Long-tailed Duck (a.k.a. Oldsquaw); Surf Scoter*; White-winged Scoter; Common Goldeneye; Bufflehead; Common Merganser*; Red-breasted Merganser; Hooded Merganser; American Coot.
- Plovers, Sandpipers and Allies: Back-belled Plover; Semipalmated Plover; Killdeer*; Black Oystercatcher*; Greater Yellowlegs; Ruddy Turnstone; Black Turnstone*; Sanderling; Western Sandpiper; Least Sandpiper; Dunlin; Short-billed Dowitcher; Wilson’s Snipe (a.k.a. Common Snipe); Red-necked Phalarope.
- Gulls and Terns: Bonaparte’s Gull; Heermann’s Gull; Mew Gull; California Gull; Thayer’s Gull; Western Gull; Glaucous-winged Gull*; Caspian Tern.
- Alcids: Common Murre; Pigeon Guillemot*; Marbled Murrelet*; Cassin’s Auklet; Rhinoceros Auklet.
What areas of CRD harbours do sea & shore birds frequent the most?
There are some valuable bird habitat areas around the CRD, and Victoria in general. Esquimalt Lagoon, Esquimalt Harbour and Victoria Harbour have been designated as federal migratory bird sanctuaries. The Chain Islets, off Oak Bay, are part of a marine ecological reserve, and provide year-round breeding grounds for Glaucous-winged Gulls, Double-crested Cormorants, Brant’s Cormorants, Pelagic Cormorants, Pigeon Guillemots and Black Oystercatchers. All resident cormorant species are on the BC Ministry of Sustainable Resource Management Red List (meaning they are extirpated, endangered or threatened in BC). Race Rocks, to the west of Victoria, provides rich feeding grounds for many species of migratory and resident seabirds.
Portage Inlet is one of the two most important bird areas in the CRD (the other being Esquimalt Lagoon). Portage is characterized by shallow water and low salinity, due to limited tidal flushing and freshwater input from Craigflower Creek. It harbours extensive eelgrass beds, which provide habitat for numerous prey species. Extensive mud flats at the mouth of Craigflower Creek provide rich foraging grounds for shorebirds that feed on burrowing shellfish, worms and crustaceans. Canada Geese rear in this area, and Double-crested Cormorants feed on herring when they spawn here.
Esquimalt Lagoon is the another important area for birds. It provides a sheltered area with low salinity, mud flats and eelgrass beds. Shorebirds, Canada Geese and Mallards feed and rest along the north shore. Diving ducks such as the Lesser Scaup, Common Goldeneye and Bufflehead feed in the open water. Mergansers and Surf Scoters are common on the outside of Coburg Peninsula. Gulls are common throughout the Lagoon.
In general, the areas of the CRD harbours where birds are found in greatest abundance throughout the year include:
- Northwestern portion of Portage Inlet, from the mouth of Craigflower Creek, to Christie Point
- Upper Gorge Waterway, from the Admirals Road bridge to the “narrows”
- West Bay, Colville Island and Lime Bay, in Victoria Harbour
- Mud flats at the mouth of Millstream Creek in Esquimalt Harbour
- Esquimalt Lagoon, particularly at the north and south ends
What are the lifestyles of seabirds, shorebirds & waterfowl?
Many species in all three groups of birds make long migrations between seasonal breeding and feeding grounds. Seabirds and shorebirds have the longest known migratory routes of all types of birds; some travel from the Arctic to the Southern tip of South America.
Seabirds may live close to shore or offshore, and feed primarily on small fishes or zooplankton (microscopic animals that float with the currents). Many seabirds are opportunistic feeders; they will change their diet according to what prey is available. Some seabirds catch their prey while in flight, while others dive and chase fish underwater by swimming with their wings or feet. Many species breed in Canada, and 500 million seabirds are estimated to breed at 500 locations along the coast of BC.
Many species of shorebirds that are observed in BC during the winter are enroute to their summer breeding grounds in the Arctic or sub-Arctic. Successful feeding during their winter migration is vital to completing this long journey and to surviving the cold temperatures of early summer in the Arctic. On the coast, they probe mud flats for invertebrates such as amphipods and worms. Some, such as the Oystercatcher, feed on shellfish. Those that travel to the Arctic tundra feed mostly on insects while inland.
Shorebirds do not moult their flight feathers all at once, as do many waterfowl. Instead, flight feathers are replaced individually and continuously; this enables them to constantly be on the move.
Some waterfowl migrate to the Arctic to breed, while others are resident in locations of B.C. throughout the year. Waterfowl may eat terrestrial vegetation (e.g. Canada Geese), marine vegetation such as eelgrass or other plants (e.g. Brant Geese and dabbling ducks), or fish and shellfish (e.g. surf scoters).
What is the status of resident & migratory birds?
Some of the populations of resident and migratory birds are at risk, due to stresses from human-caused and natural factors. Two regulatory bodies oversee endangered wildlife in BC: at the federal level, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and at the provincial level, the BC Ministry of Sustainable Resource Management (MSRM).
COSEWIC lists species as Extinct (no longer existing), Extirpated (no longer existing in the wild in Canada, but occurring elsewhere), Endangered (facing imminent extirpation or extinction), Threatened (likely to become endangered if limiting factors are not reversed), and Special Concern (particularly sensitive to human activities or natural events, and at risk of becoming Threatened).
MSRM lists species on the Red List (extirpated, endangered or threatened in B.C.), or the Blue List (of special concern due to sensitivity to human activities or natural events).
Bird species currently listed by COSEWIC and MSRM are summarised below. It is important to note that species that are not listed below are not necessarily in good shape, as it takes considerable scientific study to determine the status of species, particularly those as mobile as birds. The lists also do not show trends. Many populations of shorebirds, for example, have recently been declining quite dramatically.
Status of Endangered Bird Species Common to the CRD
|Species ||COSEWIC ||MSRM |
|Great Blue Heron ||Special Concern ||Blue list |
|Western Grebe || ||Red list |
|Double-breasted Cormorant || ||Red list |
|Pelagic Cormorant || ||Red list |
|Brant's Cormorant || ||Red list |
|Harlequin Duck ||Special Concern || |
|Surf Scoter || ||Blue list |
|Short-billed Dowitcher || ||Blue list |
|Common Murre || ||Red list |
|Marbled Murrelet ||Threatened ||Red list |
|Cassin's Auklet || ||Blue list |
How are bird populations and distributions studied?
Studying birds is challenging; they are often on the move, they breed and feed in isolated areas, they may change their migratory routes, and they flock in large numbers that can be difficult to count. Therefore, biologists must rely not only on their own observations but also those of amateur birdwatchers and hunters.
Sometimes birds are captured, banded (a small metal band with an ID number is placed around their leg), released and recaptured elsewhere or at a different time. This helps to track their movements and migrations.
The data concerning bird species and numbers on this website was gathered in bi-monthly bird counts conducted over two years (1997-1999) at various sites in the CRD harbours. Sites were divided into polygons (areas bounded by three or more line segments), and bird species and numbers within those polygons were recorded. The work was overseen by a biologist and largely conducted by volunteers. In addition, previous studies and reports were used for background information.
What threatens seabirds, shorebirds and waterfowl in this area?
Habitat loss is likely one of the greatest threats to birds. The requirements for nesting sites varies considerably between species. For example: Marbled Murrelets nest in old growth forests as much as 60 km from the coast; gulls and cormorants nest on rocks next to the ocean; Great Blue Herons nest in large trees near the water; Killdeers nest on gravel bars or in open fields. When forests are logged and shorelines are developed, nesting sites are often lost.
Valuable feeding habitat is also often lost when shorelines are altered. For example, seawalls can disrupt coastal sediment processes and cause beach erosion; many shorebirds rely on sand and mud beaches for foraging. Dredging, conducted to build structures such as wharves, can destroy eelgrass meadows and bury subtidal benthic communities, both of which supply prey for seabirds.
Although some habitat loss is simply a consequence of human population growth, often the damage can be limited. For example, ecological reserves can help to protect valuable nesting and feeding sites, and shoreline development techniques can help to ensure that habitat is preserved.
Decline of Prey Species
Many species of water birds prey on fish, crustaceans and molluscs. Therefore they are affected by activities that impact their prey. For example, cormorants feed on herring, among other species of schooling fish. For reasons that are not well understood, herring have not spawned in Portage Inlet in recent years; this may be related to a noted decline in cormorants. Other prey species such as shellfish may be reduced by human harvesting or shoreline development.
Lead poisoning is a major cause of death and sickness in many birds, including Mallards, loons and grebes, sea ducks (e.g. Harlequin ducks), geese and swans. The main sources of lead poisoning are lead shot pellets, used by waterfowl hunters, and lead sinkers and jigs, used by fishers.
Birds mistake the lead pellets or weights for prey such as small snails, or ingest it as grit, which they need in their gizzards to help grind up food. The lead is dissolved in the digestive system, and enters the bloodstream. Lead is highly toxic. It can cause death quickly or gradually as an animal’s nervous system becomes impaired and it is unable to fly, eat, find a mate or care for its young properly. Predatory birds such as bald eagles can also become poisoned when they eat birds that have been poisoned by lead.
The use of non-lead shot has been required in some areas and for certain species, but since it breaks down in the environment very slowly, it will continue to be a hazard for some time. Fortunately, there are alternatives to lead for both shot and fishing gear. (See “More Information” below.)
Many of the places where seabirds, shorebirds and waterfowl feed are also popular recreation areas, for boating, dog walking and fishing. These activities can cause stress to birds. For example, although it may seem harmless for dogs or children to chase shorebirds and waterfowl, the cumulative effect of many such disturbances can be significant. Migratory birds need to feed intensely to build up body fat and energy reserves for their long flights (some shorebirds fly for 40-60 hours continuously). Any time spent fleeing means less time for eating, and uses up valuable energy. Too much disturbance can cause birds to abandon nest sites or feeding areas. Victoria Harbour is a designated migratory bird sanctuary, however constant boat traffic and other urban activity results in relatively few birds here.
Pollution and litter
Marine pollution can come from a number of sources. When rainwater runs across paved roadways and parking lots, it picks up chemicals such as heavy metals, oil and gas, which are then discharged into the harbours. Pesticides and fertilizers used in home gardens or commercial landscaping can also be carried by rainwater into the harbours. Although industrial pollution is not discharged anymore into these harbours, historical dumps continue to provide a source of some toxic chemicals.
Birds can become ill from exposure to chemical pollution in the water. They can also ingest chemicals through their prey. Some chemicals that do not readily break down in the tissues of animals are subject to biomagnification. This means they become more concentrated as they move up the food chain, resulting in greater toxicity to higher predators such as birds. Some metals and organic chemicals such as PCB’s biomagnify.
Oils are particularly dangerous for birds, since they can reduce the insulative properties of the feathers. Birds often ingest litter such as cigarette butts, plastic bags and small pieces of styrofoam. These can cause them to choke or they may release toxic chemicals after they have been ingested.
How can I help protect seabirds, shorebirds and waterfowl?
- Work toward restoration and conservation of valuable bird habitat such as estuaries and sand and gravel shorelines, by learning more about these areas and the birds that frequent them. Go bird-watching (see links below), join a bird-watching club or get involved with a community stewardship group
- Help to keep wild birds wild. The healthiest diet for birds is supplied by nature. Bread has low nutritional value, affects birds’ digestive systems and can make them sick. Repeat feeding of birds is also detrimental as it lowers their ability to survive on their own. If you must feed the birds, please feed them grain
- Try to disturb birds as little as possible when walking along the beach
- Keep dogs on a leash while in migratory bird sanctuaries (e.g. Esquimalt Lagoon), including adjacent lands within 100 m, and in other areas where shorebirds are feeding
- Walk carefully at low tide to avoid stepping on plants and animals that are important bird food (and important in their own right!). Stay on designated paths or open beach, rather than walking through sensitive shoreline vegetation such as dune grass
- Take litter home with you, or place it in cans provided (this includes cigarette butts)
- Learn about alternatives to lead shot and fishing gear
- See the How To Help Protect Animals page for more tips
Additional Links & Information
© Image courtesy of Lotus Johnson