Herring and lesser black-backed gulls are two similar looking seabird species found across the Northern Hemisphere. While they occupy some of the same habitats and have overlapping ranges, there are several key differences between these two gull species in terms of appearance, behavior, distribution and conservation status.
Understanding how to distinguish herring gulls from lesser black-backed gulls takes some practice. Looking at differences in plumage patterns, bill size and shape, leg color and overall size are helpful identification tips. Getting to know the subtle differences in their calls and understanding their preferred nesting and feeding habitats can also aid identification.
This article will highlight the main differences between herring gulls and lesser black-backed gulls in terms of physical features, distribution, habitat, diet and behavior. Comparing and contrasting these two species provides useful context for understanding gull identification and ecology in general.
Physical Differences
Though herring gulls and lesser black-backed gulls appear somewhat similar at first glance, a closer look reveals several consistent physical differences between the two species.
Size
One of the most noticeable ways to distinguish these two gulls is overall size. Herring gulls are larger than lesser black-backed gulls, though there is some overlap between small female herring gulls and large male lesser black-backed gulls.
On average, herring gulls measure 20-26 inches (51-66 cm) long with a wingspan around 59 inches (150 cm). Lesser black-backed gulls are smaller, averaging 21-24 inches (53-61 cm) in length with a wingspan around 49 inches (125 cm).
When seen side by side, the larger size of herring gulls is usually apparent. However, size can be harder to judge without a direct comparison. Paying attention to other physical differences is needed for reliable identification.
Plumage
Plumage patterns are a more reliable way to differentiate herring and lesser black-backed gulls.
Adult herring gulls are white with light grey upper wings and black wing tips dotted with white spots. The back and upperwings are a lighter grey tone.
Lesser black-backed gulls also have white plumage with grey upper wings. But the grey back and wing color is darker, more blackish-grey compared to the paler grey wings of herring gulls. Lesser black-backed gulls also have black wing tips with very little white spotting.
Bill
Bill size and shape are useful identification clues. Herring gulls have a heavy two-toned bill that is yellow with a bright red spot on the lower mandible. Lesser black-backed gulls have a smaller, more slender all-yellow bill without any red marking.
Legs
Leg color differs between adult birds of these species. Herring gulls have pink legs, while lesser black-backed gulls have yellow legs. Watching a walking or swimming gull will reveal this key difference.
Head Shape
Subtle differences in head shape exist. Herring gulls tend to have a more rounded or bucket-shaped head. Lesser black-backed gulls have a slightly flatter and more tapered head shape. This difference is tricky to discern, but can be helpful combined with other characteristics.
Physical Trait | Herring Gull | Lesser Black-backed Gull |
---|---|---|
Size | 20-26 in length, 59 in wingspan | 21-24 in length, 49 in wingspan |
Plumage | Pale grey upperwings, white body, black wing tips with white spots | Blackish-grey upperwings, white body, mostly plain black wing tips |
Bill | Heavy yellow bill with red spot | Slender all yellow bill |
Legs | Pink | Yellow |
Head Shape | Rounded | Flatter and tapered |
Distribution and Habitat
Understanding where herring and lesser black-backed gulls live and their preferred habitats also aids identification. Though some overlap occurs, these species have different geographic breeding ranges and occupy somewhat different coastal and inland environments.
Herring Gull Range
Herring gulls have a circumpolar distribution, occurring across northern Europe, Asia, and North America. They breed as far north as Iceland and Arctic Canada and as far south as northern France and the Great Lakes. Large populations occur throughout their breeding range and around ocean coasts during the nonbreeding season.
Lesser Black-backed Gull Range
The breeding range of lesser black-backed gulls is centered across Western Europe, including countries like the UK, Netherlands, France, and Iceland. Smaller numbers breed in Greenland, at scattered inland sites in Eurasia, and on the East Coast of North America. Overall, lesser black-backed gulls have a more restricted global range compared to herring gulls.
Coastal Habitats
During the nonbreeding season, both gull species frequent coastal habitats like harbors, beaches, tidal mudflats, estuaries, and marine coastlines. Herring gulls tend to prefer more northern coastal wintering sites. Lesser black-backed gulls are more likely to winter a bit further south along the Atlantic and Pacific Coasts, or around the Mediterranean Sea.
Inland Habitats
While wintering coastal birds are difficult to separate, during breeding season their inland habitat preferences differ. Herring gulls favor islands and shoreline habitats across the northern Holarctic. Lesser black-backed gulls nest more often at inland locations like rooftops, reservoirs, and garbage dumps, especially across Europe and eastern North America.
Distribution and Habitat | Herring Gull | Lesser Black-backed Gull |
---|---|---|
Breeding Range | Circumpolar across northern Holarctic | Mainly Western Europe, scattered inland Eurasia and NE North America |
Wintering Range | Northern coastal sites | Southern coastal sites and Mediterranean |
Nesting Habitat | Islands, shorelines | Coastal and inland – rooftops, landfills etc. |
Diet and Feeding
The dietary habits of herring and lesser black-backed gulls also show some key differences. Their feeding behaviors and prey preferences are adapted to their particular habitats.
Herring Gull Diet
Herring gulls are supreme opportunistic feeders. They consume a wide variety of marine prey like fish, squid, shellfish and marine worms. But they have also adapted well to human food sources. Herring gulls often scavenge in urban areas and at garbage dumps. They do extensive kleptoparasitism, harassing other birds to steal their food.
Lesser Black-backed Gull Diet
The diet of lesser black-backed gulls overlaps with herring gulls in coastal areas, where they also eat marine invertebrates and some fish. Inland populations show more reliance on terrestrial foods though like earthworms, insects and agricultural grains. Lesser black-backed gulls only occasionally scavenge urban areas for food.
Foraging Differences
Subtle differences in how they obtain prey have been noted. Herring gulls do more surface plunging and diving to catch swimming fish. Lesser black-backed gulls use a method called ground sifting more often, walking through grass and leaf litter snapping up hidden prey. But both species exhibit flexible feeding behaviors depending on local food availability.
Diet and Feeding | Herring Gull | Lesser Black-backed Gull |
---|---|---|
Primary Prey | Marine fish, invertebrates | Marine invertebrates, worms, terrestrial insects |
Foraging Strategy | Scavenging, kleptoparasitism, surface plunging | More ground sifting, less scavenging |
Food Flexibility | Extremely opportunistic | Moderately opportunistic |
Behavior and Nesting
Aspects of breeding biology like nest sites and parenting behavior offer additional comparison points between herring gulls and lesser black-backed gulls.
Nest Sites
Herring gulls often nest in large colonies on offshore islands and coastal cliffs. Lesser black-backed gulls exhibit more solitary nesting, with just a few pairs in one location. Inland city-nesting lesser black-backed gulls also favor rooftop and industrial nest sites.
Parenting
Both species build a nest scrape lined with vegetation and feathers on the ground or a roof surface. The female lays usually three speckled olive-brown eggs.
Herring gulls are attentive parents, with both male and female alternating incubation duties and guarding chicks after hatching. Lesser black-backed gulls have a somewhat more hands-off parenting style. The chicks become independent sooner, forced to wander and find their own food earlier.
Mobbing Potential
When nests or chicks are threatened, herring gulls become extremely aggressive, mobbing predators with loud calls and dive bombing intruders. Lesser black-backed gulls are less likely to attack, but will still act defensive around the nest.
Behavior and Nesting | Herring Gull | Lesser Black-backed Gull |
---|---|---|
Nest Sites | Offshore islands, coastal cliffs, large colonies | Solitary roof and inland nests |
Parenting Style | Attentive guarding and feeding | Chicks independent sooner |
Mobbing Potential | Fiercely aggressive mobbing | Less aggressive mobbing |
Calls and Vocalizations
Listening to the calls of herring and lesser black-backed gulls provides helpful clues for identification. Their repertoires sound similar to the average ear, but differences in tone and pitch exist.
Herring Gull Calls
The most common herring gull call is a laughing “kweh-kweh-kweh” sound, with a lower pitch and huskier tone compared to lesser black-backed gulls. Other vocalizations include a short barking “kyow”, deep growl, and mewing “mee-au”. Young herring gulls emit a plaintive, squealing “peep-peep”.
Lesser Black-backed Gull Calls
The characteristic call of lesser black-backed gulls is a higher-pitched, more nasal laughing cry, sounding like “keouw-keouw-keouw”. Their growl is higher pitched than herring gulls. Chicks make a weaker, whistling “peep”. Overall their calls are sharper, clearer and less gravelly than herring gulls.
Mobbing Calls
When mobbing predators, both species produce a harsh “kek-kek-kek” vocalization. But herring gulls mob more intensely, emitting a descending wail combined with frenzied kek calls. Lesser black-backed gulls make mobbing calls less urgently and aggressively.
Vocalizations | Herring Gull | Lesser Black-backed Gull |
---|---|---|
Laughing Call | Husky, lowering “kweh-kweh” | Higher, nasal “keouw-keouw” |
Bark Call | Deep “kyow” | No distinct bark |
Chick Call | Squealing “peep-peep” | Whistling “peep” |
Mobbing Call | Harsh, intense “kek-kek” | Milder, less urgent “kek-kek” |
Identification Tips
Telling apart herring and lesser black-backed gulls can be challenging at first. But focusing on a few key identification markers makes recognizing the species much easier:
– Size – Herring gulls are larger overall
– Back and wing color – Look for pale grey wings on herring gulls vs. blackish-grey on lesser black-backed
– Amount of white in wing tips – Herring gulls have more white spots
– Bill color and size – Yellow with red spot and thicker on herring gulls, all yellow and thinner on lesser black-backed gulls
– Leg color – Pink legs confirm herring gull, yellow legs are lesser black-backed gull
– Calls – Listen for deep, husky laughs of herring gulls, higher pitched laughs of lesser black-backed gulls
– Nest location – More coastal and island nesting by herring gulls, solitary inland nesting in lesser black-backed gulls
With practice, birders can learn to identify these species by their distinct appearance, voices and behaviors. Understanding how they differ ecologically also aids in distinguishing herring gulls from lesser black-backed gulls in the field.
Summary and Conclusion
In summary, herring gulls and lesser black-backed gulls overlap in some aspects of their natural history, but show distinct differences in:
– Physical features like size, plumage tones, bill traits and leg color
– Geographic distribution and preferred habitats – lesser black-backed gulls range less far north
– Dietary preferences – herring gulls eat more fish and urban food waste
– Nest sites and parenting behavior – herring gulls nest in dense colonies and are more attentive parents
– Vocalizations – herring gull calls sound lower-pitched and hoarser
Looking at this combination of factors allows positive identification between these two sometimes confusing gull species. Herring gulls and lesser black-backed gulls fill similar ecological niches, yet have adapted in unique ways to their environments across the Northern Hemisphere.