Both the black-headed gull (Chroicocephalus ridibundus) and the Mediterranean gull (Ichthyaetus melanocephalus) are medium-sized gulls that belong to the family Laridae. They can be found across much of Europe and Asia. At a glance, they appear quite similar, with gray wings and back, white underparts, and a black head in breeding plumage. However, there are several key differences between these two species in terms of appearance, habitat, diet, and behavior.
Appearance
While both gulls have black heads during the breeding season, the black-headed gull’s hood is chocolate brown in winter. The Mediterranean gull retains its jet black head year-round. In flight, the Mediterranean gull has bright white wingtips whereas the black-headed gull’s wingtips are speckled gray and black. The Mediterranean gull has blood red legs and bill, compared to the black-headed gull’s red bill and orange-red legs. The Mediterranean is also slightly larger, measuring 15-17 inches long with a 39-43 inch wingspan. The black-headed gull is 13-15 inches in length with a 35-41 inch wingspan.
Appearance | Black-headed Gull | Mediterranean Gull |
---|---|---|
Head color | Black in summer, brown in winter | Black year-round |
Wingtips | Speckled gray and black | Bright white |
Legs | Orange-red | Blood red |
Bill | Red | Blood red |
Size | 13-15 inches long, 35-41 inch wingspan | 15-17 inches long, 39-43 inch wingspan |
In terms of plumage, juvenile birds of both species have mottled brown coloration until they reach adulthood at 2-3 years old. However, juvenile Mediterranean gulls have a pale yellow bill with a distinctive black band, compared to the black bill of juvenile black-headed gulls.
Habitat
The black-headed gull is found across large parts of Europe and Asia. It breeds in colonies at inland locations such as lakes, rivers, marshes, and wetlands. Outside of the breeding season, it frequents coastal habitats. The Mediterranean gull has a more restricted range centered around the Mediterranean Sea. It nests on islands and coastal cliffs and spends the rest of the year foraging at sea or on beaches.
Habitat | Black-headed Gull | Mediterranean Gull |
---|---|---|
Range | Across large parts of Europe and Asia | Centered on Mediterranean Sea |
Breeding habitat | Inland lakes, rivers, marshes | Coastal islands, cliffs |
Non-breeding habitat | Coastal areas | At sea or beaches |
The black-headed gull is migratory over much of its range, but Mediterranean gull populations are generally resident year-round near breeding sites. The black-headed gull has a large global population estimated at 19-26 million birds. The Mediterranean gull has a much smaller population of around 320,000-420,000 pairs.
Diet
Both gulls are opportunistic feeders, though their diets differ somewhat based on habitat. On the coast, they eat small fish, crustaceans, mollusks, and marine worms. Inland, they feed on a wide variety of insects, earthworms, grain, seeds, berries, small rodents, eggs, and even carrion and garbage.
However, the Mediterranean gull relies more heavily on live marine prey than the black-headed gull. The Mediterranean gull is known for gracefully plunge diving to catch fish underwater, whereas the black-headed gull does most of its fishing while swimming at the surface. The black-headed gull frequents more terrestrial habitats like fields and landfill sites.
Diet | Black-headed Gull | Mediterranean Gull |
---|---|---|
Marine prey | Small fish, crustaceans, mollusks, worms | Small fish, crustaceans, mollusks, worms |
Inland prey | Insects, worms, grain, seeds, rodents, eggs, carrion, garbage | Insects, worms, grain, seeds, rodents, eggs |
Fishing strategy | Mostly surface swimming | Plunge diving underwater |
Foraging habitat | Fields, landfills, inland waters | Primarily at sea |
Research has shown that the Mediterranean gull depends much more on just a few prey species like five-bearded rockling and sand lance. The black-headed gull is a more generalist feeder that switches between many types of prey.
Behavior
These two gulls differ in some aspects of their breeding and social behaviors as well.
The black-headed gull nests in dense colonies that can contain more than 25,000 pairs. Nests are built on the ground in protected areas near water. In contrast, the Mediterranean gull nests in smaller groups, rarely more than 1,500 pairs together. Their nests are built on cliff ledges or rocky islands, sometimes in crevices or small caves. This species is territorial and mates are faithful from year to year.
Mediterranean gulls are less social outside of the breeding season than black-headed gulls. The former species spends much of its time solitary or in pairs, while the latter often gathers in large flocks of hundreds or even thousands of individuals at lakes or along the coast.
Both gulls produce loud, laughing calls. However, the call of the Mediterranean gull is lower pitched and sounds more like “kyow” or “kiwee”. The black-headed gull’s most common call is a higher, more nasal “kree-ar” or “ree-arr”.
Behavior | Black-headed Gull | Mediterranean Gull |
---|---|---|
Breeding colony size | Up to 25,000 pairs | Up to 1,500 pairs |
Nest location | Ground near water | Cliffs, rocky islands |
Mate fidelity | Variable | Faithful |
Non-breeding sociality | Large flocks | Solitary or pairs |
Call | Nasal, laughing “kree-ar” | Lower “kyow” or “kiwee” |
The Mediterranean gull can be very aggressive in defending nest sites and chicks, more so than the black-headed gull. Its sharp calls are often given as warnings or during attacks on intruders.
Status and Conservation
The black-headed gull has an extremely large global population estimated at 19-26 million individuals. The species expanded its breeding range dramatically in the 19th and 20th centuries alongside human activities like agriculture and landfills. As a result, this gull is classified as Least Concern on the IUCN Red List.
In contrast, the Mediterranean gull has a much smaller population of only 320,000-420,000 pairs. However, numbers today are increasing after human persecution and egging caused declines in the late 19th/early 20th centuries. The species has rebounded following conservation efforts and legal protections, leading to a Near Threatened listing.
Major threats to Mediterranean gulls today include disturbance at breeding colonies, marine pollution, overfishing, and entanglement in fishing gear. Conservation priorities include preserving nesting sites, controlling tourism impacts, reducing marine debris, and sustainably managing fisheries.
Conservation Status | Black-headed Gull | Mediterranean Gull |
---|---|---|
Population | 19-26 million | 320,000-420,000 pairs |
Population trend | Increasing | Increasing |
IUCN Red List status | Least Concern | Near Threatened |
Major threats | None significant | Disturbance, marine pollution, overfishing, entanglement |
Conclusion
While the black-headed and Mediterranean gulls may appear rather similar at first glance, they exhibit key differences in their appearance, habitat preferences, feeding ecology, behavior, and conservation status. The Mediterranean gull is more specialized for marine habitats and is less numerous and more vulnerable to extinction threats. Ongoing monitoring and protection of breeding sites will be important for the long-term viability of Mediterranean gull populations sharing the coasts and seas with widespread black-headed gulls.