Birds With The Largest Clutch Sizes

Common Eider The common eider, a large sea duck found in the Northern Hemisphere, is known for its exceptionally large clutch sizes. These ducks typically lay between 3 and 7 eggs in a single clutch, although some nests have been documented with up to 9 eggs. Eiders are colonial nesters, and their nests are often located in coastal areas or on islands.

Mallard Mallards, perhaps the most recognizable duck species worldwide, are known for their adaptability to a wide range of habitats. They typically lay clutches ranging from 8 to 13 eggs. Mallards are highly prolific and can be found in urban ponds, wetlands, and agricultural areas.

Canvasback The canvasback is a diving duck found in North America. While they often have smaller clutch sizes than other ducks, ranging from 5 to 9 eggs, they are included on this list due to their impressive body size and striking appearance.

American White Pelican The American white pelican, a large waterbird with a distinctive pouch under its bill, typically lays 2 to 3 eggs in a clutch. While this may not seem like a large clutch size, it’s worth noting that these birds engage in cooperative breeding, with several adults tending to the young in a communal effort.  American White Pelicans are large birds with a wingspan of about 8 to 9 feet (2.4 to 2.7 meters).

House Sparrow The house sparrow, a common bird in urban and suburban areas worldwide, is known for its adaptability and prolific breeding. House sparrows typically lay clutches of 2 to 8 eggs, with larger clutches occurring in areas with abundant food resources.

European Starling European starlings, introduced to North America, are another bird species known for their large clutch sizes. They usually lay between 3 and 7 eggs. These birds are often considered invasive due to their rapid population growth.  European Starlings are medium-sized birds with a length of about 7 to 9 inches (18 to 23 centimeters).

Brown-headed Cowbird Brown-headed cowbirds are brood parasites, meaning they lay their eggs in the nests of other bird species. This behavior allows them to have exceptionally large clutch sizes, as they don’t invest in parental care. A single female cowbird can lay up to 36 eggs in different host nests during a breeding season.

American Coot American coots are waterbirds found in North America. They typically lay clutches of 8 to 12 eggs, which is relatively large for a waterbird. Coots are known for their aggressive territorial behavior during the breeding season. American Coots are primarily herbivorous, feeding on aquatic plants such as pondweeds, sedges, and algae.

Northern Fulmar Northern fulmars, seabirds that inhabit the North Atlantic and North Pacific oceans, lay single-egg clutches. While this may seem small, they have a unique adaptation – if their egg is lost, they can lay a replacement egg, sometimes up to seven times in a single breeding season.

Black-crowned Night Heron Black-crowned night herons are wading birds known for their distinctive appearance. They typically lay clutches of 3 to 5 eggs. These herons often nest in colonies in trees, reed beds, or wetland areas.