Wisconsin’s vast inland lakes, mighty rivers, and Great Lakes coasts provide bountiful habitat for a diversity of gull and tern species. These elegant white and gray seabirds arrive in spring to breed in raucous colonies before heading south in fall. Their loud cries echo over waterways as they dip and dive to snatch fish from below. While often seen as pests, gulls and terns captivate birdwatchers with their aerial grace and exhibit unique adaptations that allow them to thrive. This guide explores 8 of the most common gulls and terns that call Wisconsin home each summer, describing their identifying traits, nesting habits, foraging behaviors, and migration patterns that bring bursting colonies back each year. Grab your binoculars and get ready to start spotting these masters of flight!
|Gull Type||Size||Distinguishing Features|
|Ring-billed Gull||Medium-sized||Black ring around yellow bill|
|Herring Gull||Large||Pink legs, heavy yellow bill with red spot|
|Bonaparte’s Gull||Small||Black head with white crescent behind eye|
|Caspian Tern||Large||Red-orange bill, loud raucous call|
|Common Tern||Medium-sized||Black cap, red-orange bill with black tip|
|Forster’s Tern||Medium-sized||Orange bill with black tip, staccato barking call|
|Black Tern||Small||Mostly black plumage|
|Laughing Gull||Medium-sized||Black hood, loud laughing call|
Table of Contents
1. Ring-Billed Gull (300 words)
The ring-billed gull is one of the most common gulls found in Wisconsin. It is a medium-sized gull with a wingspan of around 50 inches. Adults have white heads, gray backs, black wingtips with white spots, and yellow legs and feet. The ring-billed gull gets its name from the black ring around its yellow bill. This is a distinguishing feature that sets it apart from other similar gull species.
Ring-billed gulls breed near inland lakes and rivers across Wisconsin. They make nests of grasses, twigs, and debris on the ground, often on islands or isolated spots. The female lays around 3 eggs that incubate for around 3 weeks. Both parents feed the chicks small fish, insects, and other invertebrates. Ring-billed gulls are opportunistic feeders and will eat a variety of foods including fish, garbage, insects, earthworms, and more.
In winter, ring-billed gulls migrate south to the Gulf Coast, the Great Lakes, and the Atlantic Coast. However, some can still be spotted around open inland waters in Wisconsin during the coldest months. Their loud, laughing calls are a familiar sound around lakes and rivers in summer and can still occasionally be heard in winter. Overall, the ring-billed gull is a common, adaptable gull species found year-round in Wisconsin.
2. Herring Gull (300 words)
The herring gull is another ubiquitous gull in Wisconsin, often seen around the Great Lakes and major inland rivers. It is a large gull with a wingspan reaching up to 58 inches. Herring gulls have white heads, light gray backs, black wingtips with white spots, and pink legs. Their large yellow bill is heavy and slightly hooked at the end. Juvenile herring gulls have mottled brown plumage before molting into adult colors by 4 years old.
Herring gulls nest in noisy colonies on islands and shorelines across Wisconsin. Nests are made of vegetation and debris on the ground. Females lay around 3 eggs that hatch after an incubation of around 4 weeks. Chicks fledge 6-7 weeks after hatching. Herring gulls are opportunistic, omnivorous scavengers that eat a wide variety of foods. Fish, intertidal creatures, garbage, carrion, insects, rodents, and more all make up their diet.
Many herring gulls migrate south for winter, but some can still be found around the Great Lakes and major rivers during cold months. Herring gulls are very adaptable and populations have increased alongside human development. Their loud calls are a regular background noise along shorelines. Though once threatened by egg collecting and hunting, herring gull numbers rebounded strongly in the 20th century.
3. Bonaparte’s Gull (300 words)
Bonaparte’s gull is a small, tern-like gull species that migrates through Wisconsin each spring and fall. It spends summers breeding in Canada and winters along the Gulf Coast and southeastern seaboard. Bonaparte’s gulls are named after Charles Lucien Bonaparte, a 19th century French ornithologist and nephew of Napoleon Bonaparte.
These small gulls reach lengths of 13-15 inches with a wingspan around 33 inches. They have distinctive black heads during breeding plumage with a white crescent shape behind the eye. Their backs and wings are light gray and they have black legs and a small black bill. In non-breeding plumage, their heads are mostly white with a dark ear spot. Bonaparte’s gulls feed on insects, small fish, marine invertebrates and more.
During migration between their summer and winter grounds, Bonaparte’s gulls stop along Great Lakes shorelines, large inland lakes, and major rivers in Wisconsin. They form large flocks sometimes numbering in the thousands as they rest and feed. Peak migration is in May during their northward spring journey and September/October as they head south for winter. With their aerial agility, Bonaparte’s gulls often forage by dipping down to grab food from the water’s surface in flight.
Though not breeding in Wisconsin, migrating Bonaparte’s gulls are a welcome sight each spring and fall season as they pass through the state on their long migratory journeys. Sighting a flock of these graceful birds is a highlight for any birder in Wisconsin.
4. Caspian Tern (300 words)
The Caspian tern is the largest tern species and is commonly found nesting and feeding along Wisconsin’s Great Lakes coasts and inland lakes and rivers. Named after the Caspian Sea, these giant terns breed in scattered colonies across North America.
Caspian terns are large, long-winged birds with a wingspan reaching 50-60 inches. They have black heads and upper bodies, pale gray undersides, a thick red-orange bill, and black legs. Their calls are loud, raucous, and distinct. Caspian terns nest in colonies on sandy or rocky islands and feed primarily on small fish which they catch by diving from great heights.
In Wisconsin, Caspian terns nest on islands in Lakes Michigan, Superior, and inland lakes. Nesting colonies usually number in the dozens up to a couple hundred breeding pairs. Nests consist of scrapes in sand or gravel with 1-3 eggs laid per pair. Both parents share incubation duties lasting about 3 weeks until hatching. Chicks fledge at 6-7 weeks old.
Caspian terns migrate from more southerly wintering grounds to breed in Wisconsin from April-August before returning south in September-October. During summer, they are a common sight along Wisconsin’s coastlines, rivers, and lakes, diving for fish in their distinct manner. Their loud calls carry over the water. Conservation efforts have helped Caspian tern numbers increase in recent decades after previous declines from feather and egg collecting.
5. Common Tern (300 words)
The common tern is a widespread summer breeding resident along Wisconsin’s lakeshores and rivers. It migrates north to nest in colonies from April-August before heading back to wintering grounds in coastal areas further south. Common terns are graceful, medium-sized birds with long, pointed wings and a deeply forked tail.
Adults have gray backs and upperwings, whitish undersides, a black cap, red-orange legs, and a red-orange bill with a black tip. Juvenile common terns have darker charcoal coloring on their backs and crowns. The common tern’s wingspan reaches around 31 inches. Its short legs mean it typically hunts for fish while hovering and diving from the air rather than swimming.
Nesting common terns form noisy colonies numbering from just a few to over a thousand pairs. Colonies are situated on islands along coastlines or on platforms specially built for terns. Nesting areas are fiercely defended from intruders and other birds. Females lay 2-3 eggs in a simple scrape nest, with both parents sharing incubation duties. Chicks hatch after 3 weeks and fledge about 4 weeks later.
Common terns eat small fish and occasionally insects, catching prey by hovering and diving from flight. Watching common terns hunt gracefully along the shoreline is a highlight of summer in Wisconsin. Conservation efforts including colony management and predator control have allowed common tern numbers to increase in recent decades.
6. Forster’s Tern (300 words)
Forster’s terns are medium-sized terns that breed across Wisconsin and can be found feeding along the shores of Lakes Michigan and Superior as well as inland lakes and rivers. They winter along the Gulf Coast and migrate through the state to their breeding grounds further north.
These slender terns have pale gray backs and upperwings, white undersides, a black cap, and a deeply forked tail. Their orange bill has a black tip, and their legs are also orange. Forster’s terns have a wingspan of about 30 inches. Their calls are distinct, sounding like a rapid staccato barking.
During the summer breeding season, Forster’s terns nest in marshy areas along lakes and rivers, laying 2-4 eggs in a depression in vegetation. Both parents share incubation and feeding of the chicks after they hatch around 3 weeks later. Young birds are flying by 25 days old.
Forster’s terns feed mainly on small fish, which they catch by hovering and diving into the water. They also sometimes eat frogs, tadpoles, insects and other aquatic invertebrates. Watch for them flying and fishing over waterways in Wisconsin during summer. Migrating flocks pass through in April-May and August-October as they travel between wintering and breeding areas.
Conservation efforts have helped stabilize Forster’s tern numbers in recent decades after population declines due to hunting for feathers and habitat loss. Ongoing management of breeding sites is important for maintaining tern populations.
7. Black Tern (300 words)
The black tern is a small, uniquely colored tern found across Wisconsin in summer. It breeds in colonies in marshy wetlands and along the edges of lakes and rivers. Black terns spend winters along the Atlantic and Gulf Coasts before migrating north to their breeding grounds each spring.
As their name suggests, black terns have darker plumage than other tern species. Adults have black heads, a black body, gray upper wings, and whitish underwings. Their tail is lightly forked and their legs are black. Black terns have a 25 inch wingspan and a short, straight black bill.
Black terns nest in loosely grouped colonies in wetland areas, laying 2-3 eggs in a depression on floating vegetation or muskrat mounds. Parents take turns incubating the eggs for around 3 weeks until hatching. Chicks fledge in another 3 weeks, relying on their parents for food during this time.
Foraging black terns fly over waterways grabbing insects and small fish from near the surface in a unique hovering, dipping manner. They also occasionally eat amphibians and aquatic invertebrates. Watch for them feeding in marshy areas and along the shorelines of Wisconsin’s lakes and rivers in summer. Their high-pitched call carries over the water as they fish.
Habitat loss has caused black tern numbers to decline over the past decades. Conservation efforts focus on protecting and managing wetland nesting areas to support breeding populations in Wisconsin.
8. Laughing Gull (300 words)
The laughing gull is a unique summertime gull visitor to Wisconsin. It breeds primarily along the Atlantic Coast and Gulf of Mexico before dispersing northward after breeding season ends. The laughing gull gets its name from its loud, laughing call.
This medium-sized gull has a dark gray hood, white head, grayish back and upperwings, black wingtips, and white undersides. Its legs are black and its bill is black with a red spot near the tip of the lower mandible. Laughing gulls reach lengths of 17-20 inches with a 43 inch wingspan.
During summer, laughing gulls occur along Wisconsin’s Lake Michigan and Lake Superior coasts. They are also occasionally spotted inland at lakes and rivers. These gulls likely wander north chasing food sources and spreading out after breeding further south.
Laughing gulls eat a varied diet including insects, fish, crabs, mollusks, and other small aquatic creatures. They forage in shallow waters and intertidal zones as well as scavenging scraps from boats and piers. Their loud, cackling calls ring out as they fly and feed.
While laughing gull numbers have declined in parts of their core range, they have shown increases along the Great Lakes thanks to greater food availability from human sources. Continued management and monitoring is important to track populations of this unique migratory gull visitor to Wisconsin’s coastal zones.