New Jersey’s coastline, bays, and inland waterways support at least half a dozen gull species across the course of a year, with some breeding along the shore in summer and others arriving from the north once temperatures drop. The Laughing Gull, Herring Gull, and Great Black-backed Gull are probably the three most recognizable residents, but Ring-billed Gulls, Bonaparte’s Gulls, and a handful of rarer visitors round out the list. Knowing which species you’re looking at changes how you understand the ecology of the Jersey Shore, because these birds occupy surprisingly different niches despite all being lumped together as “seagulls.”
The Laughing Gull, New Jersey’s Summer Icon
If you’ve spent any time on the boardwalk between May and September, the gull screaming overhead and eyeing your funnel cake is almost certainly a Laughing Gull. Named for its loud, high-pitched call that sounds like cackling laughter, this medium-sized gull is the dominant breeding species along New Jersey’s salt marshes. Adults in breeding plumage have a jet-black head, dark gray wings, white underparts, and a reddish bill. By winter, the black hood fades to a smudgy gray patch behind the eye, and most Laughing Gulls leave for points south, making them a largely seasonal presence.
Laughing Gulls nest in large colonies on low salt marsh islands, particularly in the Spartina grass flats of places like Barnegat Bay. A study of one such colony documented roughly 5,000 pairs of Laughing Gulls nesting alongside 800 pairs of Herring Gulls, with the Laughing Gulls concentrated in the Spartina alterniflora growth among pools and pans, consistently choosing the highest available ground for their nests.1Ornithology. Nest Site Selection and Competitive Interactions of Herring and Laughing Gulls in New Jersey Early-arriving pairs get the best spots, and latecomers are stuck with lower, more flood-prone real estate.
This preference for elevated nest sites is a survival strategy. Tidal flooding is the single biggest threat to Laughing Gull nests. Research tracking colonies in Barnegat Bay from 1976 to 1979 found that when high tides hit in early July, they wiped out all nests in the lower Spartina alterniflora habitat and most of those in the slightly higher Spartina patens zones.2The Condor: Ornithological Applications. Colony and Nest Site Selection in Laughing Gulls in Response to Tidal Flooding After a bad flooding year, the gulls shifted their colony locations to higher islands that contained more Spartina patens and Phragmites reed, demonstrating a colony-wide ability to learn from disaster.
Experiments manipulating the marsh habitat revealed just how precisely Laughing Gulls read their environment. When researchers cut the marsh grass in areas where gulls had nested in previous years, the birds refused to nest there. When artificial debris was placed in specific configurations, the gulls arranged their nests to match the debris layout.3Animal Behaviour. Nest-site selection by adult laughing gulls (Larus atricilla) The hypothesis is that daily tidal flooding in the weeks before breeding season teaches gulls which spots in the marsh stay above water, and they use vegetation height as a secondary cue. It’s a remarkably fine-tuned system for a bird most people associate with stealing French fries.
The Herring Gull, the Year-Round Resident
The Herring Gull is what most people picture when they hear the word “seagull.” Large, with a pale gray back, white head and underparts, pink legs, and a yellow bill marked by a red spot near the tip, it’s the quintessential gull of the mid-Atlantic coast. Unlike the Laughing Gull, which largely departs in winter, Herring Gulls are present in New Jersey year-round, breeding along the coast in summer and frequenting parking lots, landfills, and fishing piers through the colder months.
Herring Gulls in New Jersey breed in the same bay systems as Laughing Gulls, but they tend to occupy slightly different spots. In the mixed colony studied at Barnegat Bay, the 800 Herring Gull pairs nested in higher, drier areas compared to the Laughing Gulls that dominated the wetter Spartina flats.4Ornithology. Nest Site Selection and Competitive Interactions of Herring and Laughing Gulls in New Jersey Size plays a role in this partitioning: Herring Gulls are substantially larger and more aggressive, so they tend to win disputes over prime nesting territory. Laughing Gulls, with their sheer numbers, fill in the surrounding lower ground.
Adults are straightforward to identify, but immature Herring Gulls cause headaches for birdwatchers. It takes about four years for a Herring Gull to reach full adult plumage, and during that time the bird passes through a confusing series of mottled brown stages. First-year birds are almost entirely dark brown, and each successive molt brings more gray to the back and more white to the head. On any New Jersey beach in winter, you’ll see Herring Gulls in at least three or four different plumage stages, all of which look like different species to the untrained eye.
The Great Black-Backed Gull
The largest gull in the world, the Great Black-backed Gull is an imposing bird with a wingspan that can exceed five feet. Its slate-black back and wings contrast sharply with its white head and body, and its heavy yellow bill gives it a fierce look that matches its behavior. Great Black-backed Gulls are aggressive predators that will eat just about anything: fish, other seabirds’ eggs and chicks, small mammals, garbage. They’re found along the New Jersey coast year-round, though in smaller numbers than either Herring or Laughing Gulls.
This species breeds on the same barrier islands and bay marshes as its smaller relatives, and it has expanded its range southward along the Atlantic coast over the past century. In New Jersey, Great Black-backed Gulls often nest near Herring Gull colonies, and the two species are frequently studied together because their populations track similar environmental pressures. A study of heavy metals in bird eggs across Barnegat Bay found significant differences among species for nearly all metals tested, with Great Black-backed Gull eggs showing lower mercury levels than some other species nesting in the same area.5PubMed. Food chain differences affect heavy metals in bird eggs in Barnegat Bay, New Jersey Those differences reflect what each species eats rather than how contaminated their shared habitat is.
In winter, Great Black-backed Gulls become more conspicuous at harbors, landfills, and fishing docks. They are the bird most likely to dominate a feeding flock, shouldering aside Herring Gulls and stealing food through sheer size. Despite their intimidating presence, they are less numerous than the other two common breeders and tend to nest in smaller, more scattered groups.
The Ring-Billed Gull and Other Winter Visitors
If you spot a gull in a New Jersey parking lot or farm field between October and April, there’s a good chance it’s a Ring-billed Gull. Slightly smaller than a Herring Gull, with a distinctive black ring encircling the bill near the tip, pale yellow eyes, and yellowish-green legs, this species breeds mainly around the Great Lakes and interior Canada. Come fall, enormous numbers move to the coast. Ring-billed Gulls are probably the most abundant gull in many inland parts of New Jersey during winter, congregating around shopping centers, reservoirs, and agricultural fields in numbers that can reach the hundreds or thousands.
Ring-billed Gulls and Herring Gulls are the pair most often confused with each other. Size is the easiest field mark: a Ring-billed Gull is noticeably smaller, roughly the size of a crow, while a Herring Gull is closer to a small goose. The bill ring versus the red spot is also diagnostic, though immature birds of both species look frustratingly similar in their brown juvenile plumage.
Bonaparte’s Gull is another winter visitor, but it looks nothing like the larger species. It’s a dainty, almost tern-like gull with a thin black bill, a conspicuous white flash on the leading edge of the wing, and a small dark ear spot in nonbreeding plumage. Bonaparte’s Gulls tend to favor estuaries and tidal creeks, picking small fish and invertebrates from the water’s surface rather than scavenging on land. You’re most likely to see them along the coast from late fall through early spring, often in loose flocks that wheel and dip low over the water.
Rarer Gulls Worth Knowing
A few other gull species appear in New Jersey regularly enough to be worth mentioning, even though you’re unlikely to see them without some effort. The Lesser Black-backed Gull, a European species that has become an increasingly common winter visitor along the entire East Coast, can be found mixed in with flocks of Herring and Great Black-backed Gulls. It’s intermediate in size between the two and has a dark slate-gray back that is noticeably lighter than the jet-black mantle of the Great Black-backed. Its legs are bright yellow, which helps distinguish it from the pink-legged Herring Gull.
Iceland Gulls, which breed in the Arctic, occasionally show up in New Jersey during harsh winters. They’re about the same size as a Herring Gull but much paler, with light gray wings that lack the dark wingtips of most other large gulls. Glaucous Gulls, even larger and even paler, are another Arctic breeder that turns up rarely. Both are birds that get New Jersey birders excited precisely because they’re uncommon; finding one at a landfill or fishing pier in January is considered a minor triumph.
One thing that complicates identification in the field is that gulls hybridize. Herring Gulls and Lesser Black-backed Gulls, for instance, have been documented hybridizing along the East Coast, producing offspring with intermediate features that fit neatly into neither parent species’ description. This kind of crossbreeding is one reason experienced birders sometimes call an oddly plumaged gull “interesting” and move on rather than assigning a definitive species label.
Where and When to Find Each Species
New Jersey’s gull diversity shifts dramatically by season, and knowing when to look helps you narrow down what you’re seeing. The simplest framework: in summer, Laughing Gulls dominate the coast and breed in the salt marshes, Herring Gulls are present but in moderate numbers, and Great Black-backed Gulls are scattered among the breeding colonies. By winter, Laughing Gulls are essentially gone. Herring Gulls, Ring-billed Gulls, and Great Black-backed Gulls take over, joined by smaller numbers of Bonaparte’s Gulls and occasional rarities like Iceland and Glaucous Gulls.
Location matters too. The open beach and boardwalk areas from Sandy Hook to Cape May are prime Laughing Gull and Herring Gull territory in summer. Barnegat Bay’s salt marshes are where the large nesting colonies concentrate. In winter, inland sites become important: reservoirs in central and northern New Jersey, farm fields in the Delaware Valley, and landfills anywhere in the state all attract large gull flocks, especially Ring-billed and Herring Gulls. The Delaware Bay shore in spring is its own spectacle, when horseshoe crabs spawn and draw enormous numbers of shorebirds. Gulls participate in that feast too, feeding on the abundant crab eggs alongside migrant sandpipers and other species.6PubMed. Shorebird predation of horseshoe crab eggs in Delaware Bay: species contrasts and availability constraints
How Gulls Compete for Nesting Space
New Jersey’s breeding gull colonies are not harmonious neighborhoods. Space on the salt marsh is limited, flooding is a constant threat, and species with different body sizes and temperaments are all trying to nest in the same general area. The dynamics of how they share that space tell you a lot about each species’ ecology.
Laughing Gulls, as the smaller species, nest at higher densities and tolerate closer neighbors. Their nest-site decisions are driven primarily by the physical landscape: marsh elevation, vegetation height, and tidal exposure. Research in Barnegat Bay showed that Laughing Gulls returned to the same discrete areas of the marsh year after year, homing in on subtle elevation differences that would be invisible to a casual observer.7Animal Behaviour. Nest-site selection by adult laughing gulls (Larus atricilla) Herring Gulls, being larger and more dominant, claim the prime high-ground spots and push Laughing Gulls into the lower, riskier habitat. The result is a spatial gradient: Herring Gulls on the best ground, Laughing Gulls filling in around them, and Great Black-backed Gulls scattered at the edges or on separate islets where they can dominate without the density of the Laughing Gull masses.
Nest failure in these mixed colonies comes from multiple directions. Predation and flooding are the two biggest threats, but human disturbance and nest abandonment also play roles. Research on beach-nesting birds in New Jersey, including studies of Piping Plovers that share the same coastal habitats, documented that predation, human destruction, abandonment, and flooding all contributed to nest loss.8The Condor: Ornithological Applications. Physical and Social Determinants of Nest-Site Selection in Piping Plover in New Jersey Gulls face many of the same pressures, especially on low-lying marsh islands where a single abnormally high tide can erase an entire season’s nesting effort in hours.
What NJ Gulls Are Eating, Including Things They Shouldn’t
Gulls are famously omnivorous, and each species’ diet reflects both its size and its habitat preferences. Laughing Gulls eat insects, small fish, crustaceans, and whatever human food they can grab. Herring Gulls are broader scavengers, comfortable eating fish, invertebrates, garbage, and smaller birds. Great Black-backed Gulls are active predators more often than the other two, taking other birds’ eggs and chicks, large fish, and even adult birds on occasion.
Unfortunately, their willingness to eat almost anything means gulls also ingest debris. A study of three gull species that feed in landfill environments found that Herring Gulls, Great Black-backed Gulls, and Iceland Gulls all ingested plastic and other debris including metal, glass, and building materials. One bird had a metal fragment embedded in an abscess in its stomach.9PubMed. Plastic and Non-plastic Debris Ingestion in Three Gull Species Feeding in an Urban Landfill Environment The study found no significant differences among species, age classes, or sexes in how much debris they ingested, and no clear link between plastic ingestion and the birds’ body condition. That last finding doesn’t necessarily mean the debris is harmless; it may simply mean the birds process and pass most of it before it causes detectable chronic effects.
Separate research on Herring Gull pellets found plastic in about 13% of samples, consisting mostly of thin polyethylene sheets, rope and fishing line fragments, and foam.10Northeastern Naturalist. Diet and Ingestion of Plastic Debris by Herring Gulls Breeding at Brier Island, Nova Scotia The pieces were small, averaging under 17 millimeters in length, and all were classified as consumer-use plastics rather than industrial pellets. For a species that feeds along the wrack line, in harbors, and at dumps, encounters with debris are essentially inevitable.
Gulls as Indicators of Coastal Pollution
Because gulls sit near the top of coastal food chains and eat from a wide range of sources, they make useful biological indicators for pollution. Researchers have used gull eggs in particular to track heavy metal contamination across different parts of the New Jersey coast. A study of Herring Gull eggs at six breeding colonies across the New York Bight found significant differences in metal concentrations from site to site, though the patterns varied by metal. Eggs from Shooter’s Island in Newark Bay ranked first or second for five of six elements measured, consistent with its location in one of the most industrialized estuaries on the East Coast. Meanwhile, mercury levels were highest at the Lavallette colony in northern Barnegat Bay, a comparatively isolated site, suggesting that mercury contamination follows different pathways than metals like chromium and lead.11PubMed. Spatial patterns in a bioindicator: heavy metal and selenium concentration in eggs of herring gulls (Larus argentatus) in the New York Bight
A broader comparison of egg contaminants across five bird species in Barnegat Bay reinforced that what each species eats matters more than where it lives. Mercury showed the greatest variation among species, with fish-eating birds accumulating much more than those feeding lower on the food chain.12PubMed. Food chain differences affect heavy metals in bird eggs in Barnegat Bay, New Jersey For Herring Gulls specifically, their mixed diet of fish, invertebrates, and garbage puts them at intermediate mercury levels, enough to be useful as a pollution barometer but generally below the concentrations seen in strictly fish-eating species.
This monitoring role is one of the underappreciated reasons gulls matter ecologically. They’re easy to dismiss as pests, the noisy birds stealing your sandwich at the beach. But their eggs, their movements, and their health tell researchers a great deal about the condition of the bays, marshes, and ocean they depend on. When metal levels spike in gull eggs from a particular colony, it’s a signal that something in that local food web deserves a closer look.
Telling Them Apart in the Field
For a quick identification guide, here are the field marks that matter most for the common New Jersey species:
- Laughing Gull: Black head in summer (grayish smudge in winter), dark gray wings, reddish bill in breeding season. Medium-sized. The only gull with a fully black hood that’s common on the NJ coast in summer.
- Herring Gull: Pale gray back, pink legs, yellow bill with red spot. Large. Present year-round. Immatures are mottled brown and take four years to reach adult plumage.
- Great Black-backed Gull: Very large, with a black back and wings, white head, and heavy yellow bill. Pink legs. Dwarfs the other species.
- Ring-billed Gull: Similar to Herring Gull but smaller, with a distinct black ring on the bill and yellowish-green legs. Mostly a winter visitor. Common in parking lots and inland areas.
- Bonaparte’s Gull: Small and tern-like. Thin black bill, white wing flash, dark ear spot in winter plumage. Found along estuaries in fall through spring.
The biggest challenge is immature birds. Young gulls of every species go through years of confusing, intermediate plumages before they look like the adults pictured in field guides. If you see a large brownish gull and can’t place it, you’re almost certainly looking at an immature Herring Gull or Great Black-backed Gull, since those are by far the most common large gulls along the coast. Size helps: if it’s enormous, lean toward Great Black-backed; if it’s merely large, lean toward Herring Gull. Smaller brown gulls in winter might be immature Ring-billed Gulls, which go through a similar but faster progression and reach adult plumage in about three years instead of four.