Seabird and waterbird colonies: avoiding disturbance

Common Murre Colony © Thinkstockphotos
Photo: © Thinkstockphotos.
Common Murre Colony

Seabirds and waterbirds are particularly vulnerable to the effects of human disturbance. These guidelines are designed to increase awareness of the sensitivities of Canada’s seabird and waterbird colonies to disturbance, provide information on the applicable legal protection, and provide guidance on appropriate behaviour to follow when near breeding colonies of seabirds and waterbirds in order to avoid and minimize disturbance.


Seabirds and waterbirds

Seabirds are birds that frequent coastal waters and the open ocean; some are found exclusively in the marine environment. They include puffins, gannets, murres, razorbills, guillemots, shearwaters, petrels, auklets, murrelets and fulmars. Some seabirds can be found in both marine and freshwater areas, these include gulls, terns and cormorants (see Legal protection below for details on legal protection, acts and regulations). In general, seabirds have long life spans and low reproductive rates, with many species only laying one egg per year. They often nest on islands, on cliff-faces or in other inaccessible locations to avoid predators, and several species may nest together in mixed colonies. Some seabirds nest on ledges or on open rock, while others nest under boulders, in crevices or in burrows they have excavated in the soil. Colonies in Canada range in size from a few pairs of breeding terns or gulls to over a million pairs of Leach’s Storm-petrels.

Most species spend much of the year at sea. In spring and summer, they congregate in colonies in order to court, mate, lay and incubate their eggs, and raise and feed their young. Breeding seasons along Canada’s southern oceanic coasts extend from March through September, and through the ice-free period in Canada’s Arctic.

Colonial waterbirds are the freshwater equivalent of seabirds; they share many of the behavioural and conservation traits of seabirds. In Canada, colonial waterbirds include gulls, terns, herons, egrets, Double-crested Cormorants and American White Pelicans (see Legal protection below for details on legal protection, acts and regulations). The distinction between freshwater nesters and seabirds is not always clear-cut, as many species will breed in both environments. In the freshwater environment, they usually breed on islands; however, they will also breed on undisturbed mainland areas, e.g. peninsulas, fenced off areas near water and even on roof tops, and some species breed in marshes. In marine areas, they breed in coastal mainland areas as well as on coastal islands. The breeding season for colonial waterbirds extends from March through September, and through the ice-free period in Canada’s Arctic.

Colonies are vulnerable to habitat loss and destruction, and to the impacts of catastrophic events such as storms, disease, and oil spills. Birds breeding in colonies are particularly vulnerable to the effects of human disturbance.

Humans, seabirds and waterbirds


For hundreds of years, seabirds and colonial waterbirds were exploited for meat, eggs, and feathers, and many breeding colonies were disrupted by human disturbance and development. The Great Auk, a flightless colonial-nesting seabird, was harvested to extinction by the mid-1800s. Concern over severe declines in the numbers of seabirds breeding in coastal regions of Canada’s eastern provinces is one of the issues that contributed to the adoption of the Migratory Birds Convention Act in 1917.

Legal protection

Except for cormorants and pelicans, all regularly occurring seabirds and waterbirds in Canada are protected under the Migratory Birds Convention Act, 1994 (see: the complete list of species protected under the Act). Cormorants and pelicans are protected under provincial or territorial acts and regulations. It is illegal to harass or kill migratory birds, or to destroy or disturb their nests or eggs. It is also illegal to deposit a substance that is harmful to migratory birds, or permit such a substance to be deposited, in waters or areas frequented by migratory birds. Many colonies are afforded additional protection in Migratory Bird Sanctuaries, National Wildlife Areas or National Park Reserves under federal jurisdiction or as Ecological Reserves, Wildlife Habitat Areas, Wildlife Management Areas or Wildlife Conservation Areas under provincial or territorial jurisdiction. These designations may add specific regulations that go beyond the guidelines presented here, and most protected colonies are completely closed to visitation during the breeding periods.

Under Canada’s Species at Risk Act, several species of seabirds and colonial waterbirds are classified as being at risk: Roseate Terns, Marbled Murrelets, Ivory Gulls, Ancient Murrelet, Ross’s Gull, Great Blue Heron (fannini subspecies). These birds, their residences, and when relevant, their critical habitat are given additional protection by the Act.

In addition to these designations, there are numerous provincial, territorial, regional and municipal acts, policies and guidelines that may regulate visitors’ activities. Before approaching coastal islands or mainland colonies, prospective visitors should contact relevant agencies and local landowners to determine what restrictions may apply, and to obtain any necessary permits.

Impacts of disturbance

Seabird and waterbird breeding colonies throughout North America have seen increased visitation by private boaters, picnickers, tourists and fishers. Many people are not aware that approaching colonies, landing boats, letting pets run loose, walking across breeding areas or staying too long in one spot can affect these birds. Even approaching too closely by water can put seabirds and colonial waterbirds at risk.

Disturbance can cause these birds to abandon their nests or young, or to use valuable energy reserves for defense, instead of incubating eggs and feeding their young. The presence of humans in close proximity to nests may prevent adult birds from returning to protect and feed their young, and expose eggs or young to predation, and to the lethal effects of heat, cold and rain. As many species of seabirds and waterbirds nest in hidden crevices, burrows, vegetation or on top of exposed rocky ledges, nests may not be obvious to a casual observer, especially where species are active only after dark. A careless step in a colony can destroy a bird’s breeding burrow, nest, eggs, or chicks.

When adult birds are flushed, many of the young chicks wander from their nest site and may fall to the water, be taken by predators, or be pecked to death by neighbouring birds. Some species are particularly sensitive at certain stages of their breeding cycle. For example, disturbance can cause chicks to leave the nest too soon, resulting in high chick mortality. Young herons are particularly prone to leaving their nests when they are disturbed.


Environment and Climate Change Canada recommends that, during the breeding season, people stay off seabird and waterbird colonies, maintain appropriate buffer zones around colonies, and avoid any disturbance of migratory birds.

Human activities in waters around breeding colonies, such as fishing and boating or low-altitude flying, can also put these birds at risk. Such activities should be kept far enough away to avoid flushing birds from their nests, or causing them to dive at you in an attempt to drive you away from the colony. In coastal areas, colonial nesting seabirds often share rocky islands and ledges with other wildlife, such as seals or sea lions. You know you are too close if these marine mammals become restless and plunge into the water. In all cases where you may be disturbing seabirds and waterbirds, move away as quickly and quietly as possible.

Researchers requesting access to bird colonies should contact their local Canadian Wildlife Service office for permitting requirements.

Many protected areas (Migratory Bird Sanctuaries, National Wildlife Areas, National Parks, etc.) that contain breeding colonies have specific restrictions regarding buffer zones on land and in water, as well as flight restrictions. Please contact the local Canadian Wildlife Service office for more information on these restrictions.

General guidance on reducing disturbance to colonies that do not have other restrictions, are given below.

On land

  • In general, maintain a distance of at least 300 m from seabird and waterbird colonies. It may be possible to approach closer at authorized and supervised locations where appropriate fenced viewing facilities have been established.
  • For high-disturbance activities (e.g. drilling, blasting), maintain a buffer of at least 1 km from colonies.

If you should inadvertently find yourself at a colony, leave as quietly as possible and without sudden movements. Your local Canadian Wildlife Service office would appreciate hearing of a new colony location.

On the water

  • In general, maintain a minimum distance of at least 300 m from all areas of the island or colony occupied by seabirds and waterbirds.
  • Always travel at steady speeds when close to seabird and waterbird colonies, moving parallel to the shore, rather than approaching the colony directly.
  • Avoid any sharp or loud noises, do not blow horns or whistles, and maintain constant engine noise levels.
  • Do not pursue seabirds or waterbirds swimming on the water surface, and avoid concentrations of these birds on the water.
  • Where possible, only use certified tour boats or accredited guides.
  • Anchor large vessels, such as cruise ships, at least 500 m from the breeding islands and only approach as close as 300 m in smaller vessels. If closer access is required, please contact Environment and Climate Change Canada's Canadian Wildlife Services office in your region.
  • Never dump waste or garbage overboard, because
    • even small amounts of oil can kill birds and other marine life, and habitats may take years to recover; and
    • fishing line, cans, plastic bottles and other plastic waste can injure or kill birds.

From the air

  • Helicopters and other aircraft should keep well away from breeding colonies, as aircraft can cause severe disturbance to seabird/waterbird colonies, and there is a serious risk of collision with flying birds.
  • Please consult with the appropriate regional Canadian Wildlife Service office for guidelines on appropriate flight altitudes and horizontal distances in order to minimize disturbance to bird colonies.
  • Protected areas such as Migratory Bird Sanctuaries and National Wildlife Areas may have specific restrictions regarding flight altitudes. Pilots should contact the appropriate regional Canadian Wildlife Service office for these restrictions.

Further information:

For more information on seabirds or colonial waterbirds and their habitats, guidelines, restrictions and permit requirements for visiting their colonies, and information on ways to observe them without putting them at risk, please contact Environment and Climate Change Canada’s Canadian Wildlife Service office in your region.

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