Where do Ring-billed Gulls nest?

The Ring-billed Gull (Larus delawarensis) is a medium-sized gull species that breeds in North America. Ring-billed Gulls build their nests in a variety of habitats near water, including lakes, rivers, marshes, and coastal areas. Their nesting habits and preferred nesting locations vary across their wide geographic range.

Some key facts about where Ring-billed Gulls nest:

• Ring-billed Gulls nest colonially in colonies ranging from just a few pairs up to several thousand pairs.
• They prefer to build their nests on the ground on low islands, sandbars, beaches, rooftops, breakwalls, or wetlands.
• Vegetation such as grasses or shrubs are used to build the nest, which is a shallow depression lined with materials like twigs, grass, seaweed, or other debris.
• Ring-billed Gulls often nest in mixed colonies alongside other gull species.
• Nesting occurs between April and August, varying by latitude.
• The female typically lays a clutch of 2-4 eggs.
• Both parents incubate the eggs for around 4 weeks until hatching.

In the sections below, we’ll take a closer look at the nesting habits of Ring-billed Gulls across different regions of North America.

Nesting Habits in the Northeastern United States and Southeastern Canada

The Ring-billed Gull breeds across much of northeastern North America, including in the following areas:

• Great Lakes region (including the states of Michigan, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York)
• St. Lawrence River Valley
• Atlantic provinces of Canada
• New England

In these areas, Ring-billed Gulls prefer to nest colonially on islands in the Great Lakes and other inland lakes. Some key nesting sites include:

• Lake Michigan islands like Beaver Island
• Lake Huron islands such as Chantry Island and Charity Island
• Lake Erie islands like Middle Island and East Sister Island
• Lake Ontario islands including Pigeon Island, Snake Island, and Spider Island
• Oneida Lake and lakes in central New York
• Isles of Shoals off New Hampshire

Nesting also commonly occurs in coastal habitats along the Atlantic Ocean, such as on islands in Massachusetts, Maine, and Atlantic Canada.

Inland, Ring-billed Gulls may nest on rooftops near lakes or rivers. One notable example is the colony on the rooftops of Wayne State University in Detroit, Michigan.

Colony Sizes

Colony sizes of Ring-billed Gulls in the northeast vary substantially, ranging from just a few breeding pairs up to colonies of thousands of pairs. Some examples:

• Middle Island, Lake Erie: 8,500 pairs
• Pigeon Island, Lake Ontario: 2,500 pairs
• Charity Island, Lake Huron: 700-800 pairs
• Isles of Shoals, NH: 200-300 pairs

Nest Locations

Typical nesting locations in the northeast include:

• Sparsely vegetated areas on island beaches and shorelines
• Island interiors with grasses and low shrubs
• Bare ground on rocky islands and islets
• Gravel rooftops on buildings near water

Nests are shallow scrapes or depressions built on the ground and lined with grasses, weeds, twigs or other debris.

Nesting Habits in the Prairie Provinces of Canada

The Prairie Provinces of Alberta, Saskatchewan, and Manitoba host sizeable breeding populations of Ring-billed Gulls, especially in lake-dotted regions of central and northern Alberta and Saskatchewan.

Key nesting locations in the Prairie Provinces include:

• Lake Diefenbaker in Saskatchewan
• Last Mountain Lake in Saskatchewan
• Frank Lake and Buffalo Lake in central Alberta

Ring-billed Gulls nest both along shorelines and on islands in these lakes. Colony sizes range from just a few dozen up to a few thousand pairs.

Compared to more densely-vegetated islands on the Great Lakes, prairie islands used for nesting tend to be sparsely vegetated with grasses, reeds and occasional shrubs. Nests are built on the open ground similar to colonies further east.

Nesting Habits in British Columbia

On the west coast, Ring-billed Gulls breed mainly in southern British Columbia. The two most significant colonies are located at:

• Okanagan Lake
• Kootenay Lake

At Okanagan Lake, most nesting takes place on islands near the north end of the lake, including Goose Island, Lost Island, Tiny Island, and Kingfisher Island. Colony sizes range from around 100 to 900 nesting pairs.

At Kootenay Lake, Ring-billed Gulls nest on small islands at the south end of the lake near Creston, British Columbia, often intermixed with California Gulls.

Scattered nesting also occurs at other lakes in southern British Columbia. Compared to the Great Lakes, colony sizes are substantially smaller, typically fewer than 1,000 pairs.

Nesting Habits in the Western United States

In the western contiguous United States, Ring-billed Gulls nest in lakes and rivers in the following areas:

• Northern plains states such as North Dakota and western Minnesota
• Western Great Lakes region in states like Minnesota and Iowa
• Interior mountain states including Montana, Idaho, Wyoming, Utah, Colorado, and Nevada
• Pacific Northwest in Oregon and Washington

California and southwest states including New Mexico, Arizona, and locally inland in California

Some important colony locations include:

• Great Salt Lake in Utah
• Mono Lake in California
• Flathead Lake in Montana
• Malheur Lake in Oregon
• Islands in the lower Mississippi River

Western colonies are typically smaller than those on the Great Lakes, ranging from several dozen up to 2,000 pairs. Nests are built on islands and along shorelines similar to elsewhere in their range.

Nesting Chronology

Ring-billed Gulls arrive at breeding sites between March and May depending on latitude. Egg-laying typically spans April to early July across their range:

Incubation lasts around 4 weeks, with chicks hatching from late May through August. The young fledge at around 5 weeks of age, and start migrating south as early as late July.

Factors Influencing Nest Site Selection

A number of factors influence where Ring-billed Gulls choose to establish their colonies each breeding season:

• Proximity to Foraging Areas: Ring-billed Gulls nest close to productive feeding areas like lakes, rivers, farmland, garbage dumps, and coastal waters.
• Predator Avoidance: Islands provide safety from terrestrial predators like foxes and coyotes.
• Human Disturbance: Ring-billed Gulls avoid excessive human activity when choosing nest sites.
• Vegetation Cover: Some vegetation provides nesting material, but too much cover makes take-offs and landings difficult.
• Colony Size: Larger colonies may provide protection from predators.
• Fledging Area: Wide expanses of water are needed nearby for the young to take their first flights.

Ring-billed Gulls exhibit high nest site fidelity. Pairs and colonies typically return to the same nesting locations year after year, as long as conditions remain favorable.

Adaptability of Nest Sites

Ring-billed Gulls are adaptable in their nest site requirements. If traditional island nest sites become unsuitable due to factors like predation, flooding, or human disturbance, gulls may pioneer alternative nesting locations.

Examples of adaptability include:

• Nesting on rooftops when natural island sites are limited
• Switching to more densely-vegetated islands when preferred bare islands become overcrowded
• Forming small colonies on breakwalls and harbor structures when island nesting is disrupted
• Pioneering artificial islands built specifically for nesting birds

This adaptability allows Ring-billed Gulls to take advantage of diverse man-made and natural habitats for nesting. It has contributed to the species’ abundance across North America.

Conservation Considerations

In portions of its range, Ring-billed Gulls nest in protected areas where human disturbance is limited during breeding season. This includes national wildlife refuges, provincial parks, sanctuaries, and islands that are off-limits to visitors during nesting.

For example, Middle Island in Lake Erie is part of a federal wildlife refuge with restricted access in summer. Many Lake Ontario gull nesting islands are designated provincial wildfowl sanctuaries. Access to certain Great Lakes islands is prohibited when Ring-billed Gulls are nesting.

Other management practices that can help protect gull nesting habitat include:

• Managing vegetation to maintain suitable nesting substrate
• Controlling predators like foxes, coyotes, raccoons, and gulls through exclusion or removal
• Installing signage to deter human disturbance
• Restricting aircraft overflights near colonies
• Maintaining suitable water quality and fish populations for feeding

With appropriate habitat conservation measures in place, Ring-billed Gulls are likely to continue thriving across diverse nesting locations in North America. Their adaptability provides resilience in the face of human changes to the landscape. Protecting key island colonies will be important for the future of these abundant but still vulnerable waterbirds.

Conclusion

In summary, Ring-billed Gulls nest in a variety of coastal and inland habitats across North America. They exhibit adaptability in nest site selection, allowing them to breed successfully across a wide geographic range. Conservation of island nesting colonies is important for maintaining productive breeding sites safe from disturbance and predators. With appropriate habitat management, Ring-billed Gulls can continue thriving as a ubiquitous North American waterbird.