Gaviiformes

Plongeon catmarin oisillon

Gaviiformes is an order of birds that comprises a group of aquatic birds known primarily for their diving abilities. The order is represented by a single family, the Gaviidae, and includes species commonly referred to as loons in North America and divers in the British Isles. Gaviiformes are known for their distinctive calls, striking plumage, and exceptional diving skills. They inhabit a variety of freshwater and marine environments, primarily in the Northern Hemisphere.

Characteristics

Gaviiformes are medium to large birds, with body lengths ranging from 60 to 90 cm. They are characterized by their streamlined bodies, long necks, and sharp, pointed bills. Their legs are set far back on their bodies, a feature that aids in their swimming and diving but makes them awkward movers on land. Gaviiformes have webbed feet, which they use to propel themselves underwater in search of fish, their primary diet.

The plumage of Gaviiformes is another notable feature, with most species exhibiting striking black-and-white patterns during the breeding season. In winter, their plumage becomes more subdued, with grayer tones predominating. This seasonal variation in plumage is linked to their breeding behaviors and habitat requirements.

Habitat and Distribution

Gaviiformes are found predominantly in the Northern Hemisphere, with their range extending from the Arctic regions of North America and Eurasia to more temperate zones. They are highly adapted to aquatic environments and can be found in a variety of water bodies, including lakes, rivers, and coastal marine areas. During the breeding season, they prefer freshwater habitats where they build their nests on isolated islands or along sheltered shorelines. In winter, many species migrate to the coast, where they spend the season in marine environments.

Behavior

Gaviiformes are excellent divers, capable of reaching considerable depths in pursuit of fish. They use their webbed feet for propulsion, diving from the surface and swimming underwater with great efficiency. Their diet consists mainly of fish, but they also consume aquatic invertebrates and, occasionally, plant material.

Breeding pairs of Gaviiformes are known for their elaborate courtship displays, which include synchronized swimming and diving, as well as a variety of vocalizations. Their calls, which can be heard over long distances, are one of the most distinctive aspects of their behavior, serving as a means of communication between individuals and pairs.

Conservation

Some species of Gaviiformes are considered to be at risk due to habitat loss, pollution, and climate change. The Great Northern Loon or Common Loon (Gavia immer), for example, is listed as a species of least concern by the IUCN, but its populations are facing pressures from human activities and environmental changes. Conservation efforts for Gaviiformes focus on protecting their aquatic habitats, monitoring populations, and implementing measures to mitigate the impacts of pollution and climate change.

Classification

The order Gaviiformes is classified within the class Aves, and includes the following species, among others:

• Great Northern Loon or Common Loon (Gavia immer)
• Arctic Loon or Black-throated Loon (Gavia arctica)
• Red-throated Loon (Gavia stellata)
• Pacific Loon (Gavia pacifica)

See Also

• Bird
• Aquatic bird
• Diving bird