Herring gulls and lesser black-backed gulls are two species of gull that are closely related and can look quite similar to an untrained eye. However, there are some key differences between the two species that allow birders and ornithologists to distinguish them.
In this article, we will explore the similarities and differences between herring gulls and lesser black-backed gulls in terms of their physical characteristics, behavior, habitat and distribution, diet, and conservation status. Understanding these distinctions can help anyone hoping to identify these two common gull species.
Physical Characteristics
At first glance, an adult herring gull and an adult lesser black-backed gull appear quite alike. They have similar body shapes and sizes, with herring gulls reaching around 25 inches in length and weighing 2-3 pounds, while lesser black-backed gulls reach 24 inches and weigh 1.5-2.5 pounds.
Both species have pale grey upperparts, white underparts, yellow legs and feet, and yellow bills with red spots. However, when observed more closely, some key physical differences emerge:
Plumage
– Lesser black-backed gulls have a darker grey or blackish colored back and upperwings, which gives rise to their name. Herring gulls have a lighter grey back and wings.
– Lesser black-backed gulls have bright yellow legs, while herring gulls have flesh-colored or pinkish legs.
– Lesser black-backed gulls have a yellow iris eye color, whereas herring gulls have a pale yellow to white iris color.
Bill
– The bill of a herring gull has a more curved or drooping tip than that of a lesser black-backed gull, whose bill tip is straighter.
– Lesser black-backed gulls have a bill that appears slightly thinner and more pointed than the thicker bill of a herring gull.
Head
– In flight, the head of a lesser black-backed gull appears more rounded compared to the flatter head profile of flying herring gulls.
– Lesser black-backed gulls in flight display obvious white “mirrors” at the tip of each wing, which are not seen in the wings of flying herring gulls.
Behavior
Lesser black-backed gulls and herring gulls also exhibit some subtle but noticeable differences in their behavior:
Flight
– Lesser black-backed gulls have slightly more pointed wings and often a more graceful flight style compared to the broader, heavier wingbeats of herring gulls.
Foraging
– Herring gulls are notorious opportunistic scavengers, boldly approaching humans and SCHIP food in urban areas. Lesser black-backed gulls tend to forage more naturally in marine habitats.
Calls
– The most common call of herring gulls is a loud, repeated “laughing” cry. Lesser black-backed gulls make a series of plaintive, higher-pitched calls.
Aggression
– Herring gulls are often very assertive and competitive around food sources. Lesser black-backed gulls tend to be slightly less pushy and domineering than herring gulls when feeding.
Habitat and Distribution
Herring and lesser black-backed gulls occupy overlapping but differing habitats and ranges:
Breeding Habitat
– Herring gulls nest in coastal areas but also readily in urban environments and on inland lakes. Lesser black-backed gulls strongly prefer natural coastal habitats for nesting.
Coastal Habitats
– During the non-breeding season, herring gulls frequent both coastal and inland areas. Lesser black-backed gulls are most abundant in coastal marine environments year-round.
Range
– Herring gulls have a circumpolar distribution, inhabiting cooler climates across the Northern Hemisphere. Lesser black-backed gulls are found across Western Europe and Iceland, with some smaller populations in Eastern North America.
Migration
– Many herring gull populations migrate south for the winter. Lesser black-backed gulls are more likely to remain along coastal areas year-round rather than migrating long distances.
Diet
The dietary preferences of herring and lesser black-backed gulls show some overlap as well as differences:
Foods Eaten
– Both species feed opportunistically on small fish, marine invertebrates, intertidal organisms, insects, earthworms, eggs and chicks of other bird species, and carrion.
– Herring gulls are infamous scavengers willing to eat human food waste and garbage. Lesser black-backed gulls rely more on natural foods.
Foraging
– Herring gulls forage in a wider variety of urban and agricultural areas. Lesser black-backed gulls do most of their feeding in coastal marine habitats.
– Lesser black-backed gulls will plunge dive from flight to catch prey underwater, a technique not commonly used by herring gulls.
Adaptability
– Herring gulls can survive on a broader range of foods and foraging sites. Lesser black-backed gulls are less adaptable and more dependent on traditional marine food sources.
Conservation Status
Despite some similarities, herring gulls and lesser black-backed gulls have differing conservation needs and populations trends:
Population Trends
– Many herring gull populations are stable or increasing, thanks to their ability to thrive around human activity. Lesser black-backed gull numbers have been declining in recent decades across parts of their range.
Major Threats
– For herring gulls, entanglement in marine litter and plastics is a problem. Lesser black-backed gulls face threats from reduced food availability, disturbance of nesting sites, and hunting in some regions.
Conservation Status
– Herring gulls are listed as a species of Least Concern by the IUCN Red List due to their abundance. The status of lesser black-backed gulls ranges from Near Threatened to Vulnerable depending on the regional population.
Protection
– In many areas, herring gulls receive little formal legal protection and control programs exist to limit populations. Lesser black-backed gulls receive stronger protective designations across Europe and North America.
Conclusion
In summary, while herring gulls and lesser black-backed gulls occupy a similar ecological niche and may appear rather similar, careful examination reveals key differences in their plumage, structure, behavior, habitat preferences, and conservation status. By understanding these distinguishing traits, birdwatchers and biologists can reliably tell these two gull species apart. Paying attention to plumage patterns, bill shape, leg color, wing mirrors in flight, and behavior provides the best clues for identification.
So in answer to the original question – no, the herring gull and the lesser black-backed gull are not the same species. They have distinct appearances, behaviors, and distributions once you know what differences to look for. With a bit of practice, even casual observers can learn to differentiate between these two common but distinct gull species. The ability to properly identify species is an important skill for amateur naturalists and scientists alike.