Herring gulls are migratory birds that breed in northern latitudes during the summer months and migrate south to warmer climates for the winter. Their migration patterns and wintering grounds depend on the specific breeding population.
Quick Answers
Herring gulls from different breeding populations migrate to different wintering areas:
- Most North American herring gulls winter along the Atlantic and Pacific Coasts of the United States and Mexico
- European herring gulls winter along the coasts of Western Europe from Scandinavia to Spain
- Siberian/Russian herring gulls winter in the Black Sea, Caspian Sea, and Middle East
- Iceland gulls winter off the coasts of Greenland and Newfoundland
North American Population
The majority of North American herring gulls breed across Canada and Alaska and down into the northern United States. Their wintering grounds are mainly along the Atlantic and Pacific Coasts:
- East coast birds migrate south along the Atlantic Coast to winter from New England to Florida, Gulf Coast, and Caribbean
- Midwest birds follow the Mississippi Flyway to the Gulf Coast
- West coast birds migrate down the Pacific Coast to winter from British Columbia to Baja California
- Some birds from the interior of North America migrate east or west to winter along the coasts
On the East Coast, major wintering sites extend from Massachusetts to Florida and include:
- Chesapeake Bay
- Carolinas coast
- Georgia and northeast Florida coast
- Gulf Coast of Florida and Alabama
On the West Coast, highest concentrations are found from Washington to California, including:
- Puget Sound
- San Francisco Bay
- Monterey Bay
- Channel Islands
- Los Angeles harbors
- San Diego
Some vagrants may wander even farther south to Mexico, the Bahamas, and Greater Antilles islands.
European Population
European herring gulls breed across Iceland, northern Europe, and Russia. Their migration covers relatively shorter distances than North American gulls. Key wintering areas include:
- Coasts of northwestern Europe from northern France to Denmark
- British Isles
- Low Countries of Belgium and Netherlands
- Baltic Sea
- North Sea coasts
- Black Sea
- Caspian Sea
- Mediterranean coasts
European birds are mostly short-distance migrants, though some will migrate as far south as West Africa.
Iceland Population
Herring gulls that breed in Iceland are sometimes classified as a subspecies called the Iceland gull. Their migration ranges are the shortest among herring gull populations. Most birds winter off southeast Greenland, while some migrate across the Denmark Strait to Newfoundland.
Timing of Migration
The timing of herring gull migration depends on the population:
- North American gulls start migrating south in August, with peak migration from September to November. They return north from February to April.
- European gulls migrate later from October to December, returning in March/April.
- Iceland gulls leave breeding grounds in late summer, arriving on wintering grounds by October to November. They return quickly in March.
Younger birds typically migrate later and return earlier than mature adults. Migration is a gradual process, as birds move progressively farther south (or north in spring).
Navigation and Route
Experiments with tagging and tracking herring gulls suggest that migration routes and destinations are learned behaviors, passed from older to younger birds. Herring gulls use multiple cues to navigate during migration:
- Polarized light patterns – detect direction using sunlight
- Stars – used for orientation at night
- Coastlines – provide visual guidance over water
- Smell – detect odors from upwind locations
- Earth’s geomagnetic field – sense magnetic pole positions
Their routes follow coastlines, barriers like mountain ranges, and major river systems like the Mississippi Flyway. Young gulls likely learn routes and winter sites from experienced adults.
Why Migrate?
Herring gulls migrate to take advantage of abundant food sources and milder weather during the winter months. Key factors include:
- Lack of food – Fish, invertebrates, and garbage decline or become unavailable in northern breeding areas during winter.
- Frozen waters – Makes feeding difficult as coastal areas freeze.
- Inclement weather – Avoid harsh winter storms, wind, rain, and snow.
- Less energy expenditure – Milder temperatures at wintering grounds reduces energy needs.
- Optimal breeding habitat – Northern latitudes provide excellent nesting and chick-rearing habitat in summer.
By migrating south, gulls can survive on abundant coastal food resources during winter, then return northward quickly for breeding season when conditions become favorable again.
Threats and Conservation
Although still common, threats to herring gull populations include:
- Habitat loss at breeding colonies and coastal wintering grounds
- Disturbance of nesting sites
- Declines in fishery waste
- Competition with other gull species
- Predation
- Human persecution due to conflicts
Conservation priorities include protecting breeding and wintering habitats, managing gull-human conflicts, and monitoring populations. Banding studies continue to provide insights into migration patterns and population connectivity across the annual cycle.
Conclusion
In conclusion, herring gulls are migratory birds that breed in the northern hemisphere during summer and migrate south to temperate coastal areas each winter. Different populations follow distinct migration routes from their specific breeding sites to regular wintering grounds. Their migratory habits are driven by seasonal changes in food availability, weather conditions, and access to critical breeding habitat. Maintaining diversity of migration strategies across populations provides resilience. Continued research and habitat conservation will help ensure healthy herring gull populations into the future.
