What is a seagull?
A seagull is a common name for any of the species that belong to the seabird family Laridae. There are around 50 different species of seagulls worldwide. They are found across a wide range of coastal habitats and are known for their scavenging behavior. Some key characteristics of seagulls include:
- Long, pointed wings
- Webbed feet
- Stout, slightly hooked bills
- Omnivorous diet – they eat anything from fish, mollusks, crustaceans, insects, rodents, and more
- Opportunistic feeding habits – they will readily scavenge for food sources
- Gregarious nesting habits – they nest in large, noisy colonies
Some of the most common seagull species include the herring gull, ring-billed gull, laughing gull, and California gull. The herring gull has a widespread distribution and is the quintessential “seagull” that most people are familiar with.
Seagull breeding and courtship
Seagulls reach sexual maturity around 2-4 years of age. Their breeding seasons usually align with the warmer months, which varies across species and locations. Courtship rituals involve noisy calls, aerial displays, and pairing behavior.
Once mated, the male and female will construct a nest together in a colony, usually on an island, shoreline, or elevated location like a rooftop. Nests are made from scraps of vegetation, debris, feathers, and more. The female will then lay a clutch of 1-3 eggs within the nest.
Both parents take turns incubating the eggs for around 3-4 weeks until they hatch. The chicks are semiprecocial at hatching, covered in down feathers with eyes open. The parents feed the chicks through regurgitation for 4-6 weeks until they fledge and leave the nest.
Seagull courtship rituals and displays
Seagulls engage in elaborate courtship rituals to attract and bond with a mate. Some displays include:
- Skycalling – Loud, shrieking calls given in flight
- Head tossing – Repeatedly throwing head back
- Parading – Walking with an erect posture around potential mates
- Aerial displays – Flying in exaggerated loops and dives
- Billing – Gentle tapping of bills between mates
- Nest building – Mates work together to build nests
These displays stimulate pair bonding. The male often initiates courtship through skycalling and aerial displays. Once paired, mutual billing and nest building help maintain the bond.
Seagull nesting, eggs, and chicks
Nest sites
Seagulls nest in large, dense colonies that can number into the thousands of pairs. Nest site selection depends on the species but often includes:
- Islands – Isolated and secure from mainland predators
- Beaches – Open with a good view and access to the ocean
- Cliffs – Protected ledges on rocky coasts
- Rooftops – Elevated and safe from disturbance
- Marshes – Islands of vegetation in wetlands
Nesting in groups provides safety through more vigilance against predators. However, the close quarters also means high competition for nesting space and materials.
Nest Structure
Seagull nests are bulky, mound-shaped structures built from any debris the birds can find. This includes:
- Sticks
- Seaweed
- Feathers
- Shells
- Bones
- Garbage
- Plants
- Dirt
The nest provides a shallow depression to cradle the eggs and shelter newly hatched chicks. Both the male and female work to build the nest, often adding to it between breeding seasons.
Eggs
Female seagulls lay clutches of 1-3 eggs within the nest. The eggs are light tan to brown with dark splotches for camouflage. Incubation lasts around 3-4 weeks until hatching.
Some key facts about seagull eggs:
- Size – Typically 2.5-3 inches long
- Shape – Tapered or oval
- Clutch size – Usually 2-3 eggs
- Incubation – 23-28 days by both parents
- Hatching – Semi-precocial, down covered with open eyes
The parents share incubation duties, rotating every 1-2 days. They’ll leave the nest to search for food and return to incubate.
Chicks
Seagull chicks hatch covered in down. Their eyes are open but they cannot leave the nest initially. The parents feed the chicks through regurgitation. Chicks fledge at 4-6 weeks, when they develop wing feathers strong enough for flight.
Early growth of seagull chicks:
- Week 1 – Down covered, require constant brooding
- Week 2 – Down is replaced by juvenile plumage
- Week 3 – Feathers grow for flight
- Week 4 – Fully feathered and active, start flapping wings
- Week 5 – Able to flutter short distances
- Week 6 – Fledge from the nest
After fledging, the parents continue to feed and protect the juveniles until they become independent. Full adult plumage doesn’t develop until 2-3 years old.
Seagull feeding habits and diet
Seagulls are omnivores and highly opportunistic in their feeding habits. They will eat just about anything they can get their hands on, both through scavenging and hunting. Their diverse diet includes:
Seafood
Seagulls flock to ocean shores and intertidal zones to feed on:
- Small fish
- Crabs
- Mussels
- Clams
- Shrimp
- Krill
- Squid
They use their hooked beaks to catch live prey or scavenge washed up seafood from tidal areas.
Insects
From beaches to fields, seagulls consume a variety of insects like:
- Flies
- Grasshoppers
- Beetles
- Caterpillars
- Ants
- Worms
- Spiders
Insects provide an abundant protein source, especially to feed growing chicks.
Rodents and Eggs
Gulls will prey on rodents, eggs, and hatchlings of other bird species. Examples include:
- Mice
- Voles
- Rats
- Bird eggs
- Turtle eggs
These prey items supplement the seabird diet and provide nourishment for breeding adults and chicks.
Garbage and Scavenging
Seagulls have adapted readily to scavenging human garbage and food waste. They congregate wherever people dispose of food scraps, including:
- Landfills
- Trash cans
- Fast food parking lots
- Picnic areas
- Fishing ports
Their opportunistic feeding gives them a bad reputation. But in many cases, the ample food supply helps populations thrive.
Digestion and salt glands
Seagulls have special glands above their eyes which are their equivalent of kidneys. These glands remove excess salt from the seagulls’ bodies, allowing them to drink saltwater and feed on salty marine prey. Their digestive system is also adapted for their varied diet, allowing them to consume fish, garbage, and more.
Seagull migration patterns
Different seagull species demonstrate varying migration habits depending on food availability and breeding habitat.
Resident
Some seagulls like the California gull are non-migratory and live year-round in the same region where they breed. They may relocate slightly between the breeding colony and winter feeding areas.
Partial
Many coastal species are partial migrants – some individuals migrate while others remain resident year-round. Migration may depend on factors like food availability and an individual bird’s age.
Long distance
Species like the lesser black-backed gull undertake long distance migrations, traveling thousands of miles between distinct breeding and nonbreeding ranges. Their migration follows seasonal food availability.
Some patterns seen in migratory seagulls:
- Northward migration in spring to reach breeding grounds
- Return south in fall to warmer nonbreeding areas
- Travel mostly overland and along coasts
- Winter along southern coasts and the Gulf of Mexico in the US
- Young birds often winter further south than adults
Tracking studies show gulls can travel 50-100 miles or more each day during migration, navigating to specific breeding sites.
Seagull behavior patterns
Foraging
Seagulls are highly opportunistic and adaptable when searching for food. They utilize a range of foraging techniques:
- Scavenging – Finding carrion or human garbage and food waste
- Beach patrolling – Walking along shorelines scouting for food
- Tidal zone feeding – Scavenging the intertidal zone when tides go out
- Surface plunging – Diving from flight into the water to catch prey
- Kleptoparasitism – Stealing food from other birds and animals
Younger seagulls often adopt more aggressive techniques like kleptoparasitism. As they mature, they become more efficient foragers.
Roosting
Seagulls congregate in large groups to roost or rest in between periods of active foraging. Preferred roost sites include:
- Islands
- Breakwaters
- Cliffs
- Beaches
- Piers
- Waters offshore
Coastal cities provide ample roosting sites like building rooftops with easy access to garbage as food.
Bathing and Preening
Seagulls bathe frequently, whether in freshwater or the ocean. Their preen gland secretes oils that they spread over their feathers to maintain waterproofing. Preening also helps realign feathers and remove parasites.
Reasons for Seagull Sounds
Seagulls make a range of familiar sounds from laughing calls to begging screams. Some reasons they vocalize:
- Courting and bonding with mates
- Defending nesting territories
- Begging for food from parents
- Warning others of predators
- Communicating hunger, alarm, or contentment
- Keeping the flock together while flying or roosting
Their loud, familiar cries carry well in their coastal habitat. The gull colony is a noisy place with adults and chicks constantly vocalizing.
Seagull habitat range and distribution
Region | Example Species |
---|---|
North America | Herring gull, ring-billed gull, California gull, laughing gull |
Europe and Asia | Black-headed gull, common gull, herring gull, Armenian gull |
Africa | Gray-headed gull, Hartlaub’s gull, Caspian gull |
South America | Kelp gull, gray gull, Andean gull |
Oceania | Silver gull, Pacific gull, red-billed gull |
Seagulls have a nearly worldwide coastal distribution across temperate to polar regions. They are found on every continent except Antarctica.
Some key habitats seagulls occupy:
- Coastlines
- Islands
- Cliffs
- Beaches
- Rivers and lakes
- Cities
- Garbage dumps
- Fishing ports
Any combination of open habitat near water and food sources suits seagulls well. Their adaptability allows them to thrive alongside humans.
Seagull conservation status
Most seagull species have thriving, stable populations due to their broad habitat tolerance and opportunistic diet. However, a few localized populations of large gulls are in decline, facing threats like:
- Disturbance of nesting colonies
- Pollution and contamination
- Food shortages from overfishing and decline of fisheries waste
- Predation of eggs and chicks by expanding populations of crows, ravens, foxes, etc.
- Entanglement in marine debris and plastic pollution
Specific species of conservation concern include:
- European herring gull – Near Threatened
- Audouin’s gull – Near Threatened
- Relict gull – Vulnerable
- Saunders’s gull – Vulnerable
For most seagulls, their flexible foraging strategies continue to allow substantial populations despite some threats. But conservation measures are needed where colonies face significant disturbance or mortality risks.
Conclusion
Seagulls exhibit remarkable adaptability to thrive across a variety of coastal and urban habitats. Their lifecycle revolves around breeding colonies where pairing, nesting, and chick rearing occurs. Seagulls are opportunistic and voracious feeders, consuming anything from fish to garbage depending on local availability. While often considered pests, they fill an important niche in many ecosystems. Some populations do require conservation measures where significant habitat loss or reproductive threats occur. Overall, the future looks bright for most of the world’s seagull species due to their resilience and ability to take advantage of human food waste.