By Alex Steele
Geographic Range
Larus canus, the Mew Gull, has a range that spans throughout the Northern Hemisphere. It is found in Europe, Asia, North Africa and North America. (Bent, 1963; Felix, 1998)
Biogeographic Regions:
nearctic 
(native ); palearctic (native ); oceanic islands (native ); arctic ocean (native ); atlantic ocean (native ); pacific ocean (native ).
Habitat
Mew gulls flourish in and along coastal ranges, tidal estuaries, interior lakes and marshy grasslands. (Bent, 1963)
These animals are found in the following types of habitat:
saltwater or marine ; freshwater .
Physical Description
(10.21 to 19.43 oz; avg. 15.21 oz)
(15.75 to 18.11 in; avg. 16.93 in)
(46.85 to 48.03 in; avg. 47.44 in)
Mew gulls have an average length of 40 cm (1.3 ft.), with slender, yellowish-green legs and webbed feet. Male and Female gulls have a similar appearance, although males usually are a bit larger. They have gray wings and back with a plain white head and a greenish-yellow bill. The wingspan is usually around 119 to 122 cm (47 to 48 in.). Young gulls plummage is brown and spotted with tan; their beak is dark with a pink undertone. They will not develop adult coloration until about 27 months. (Felix, 1998; Del Hoya, 1996)
Some key physical features:
endothermic ; bilateral symmetry .
Reproduction
March and early April
Breeding among Mew Gulls occurs in colonies on the coasts of Scandinavia, Finland, Russia, Great Britain, Ireland, Denmark, Poland, Germany, Alaska, northwest Canada and on occasion, Holland and France. They are usually already paired when they arrive in March and early April at the breeding grounds. During the initial courtship the female will make primary contact, begging the male for food in a crouched posture. They will generally create large nests, which are almost entirely constructed by the female, while the male keeps his distance, occasionally bringing building materials. The nest itself will be made up of many different materials, such as seaweed, twigs, mosses, bark, grasses, and weed stalks.Mew Gulls tend to build their nests on bare rocks or hummocks.(Bent, 1963; Harrison, 1983; Royal BC Museum, 1995; USGS, 2001; Ehrlich, Dobkin & Wheye, 1988)
Mating systems:
monogamous .
Mew Gull eggs are a light brown/olive with brown markings, and are about 57 mm(2.2in) in length. They are laid in March and early April during the breeding season. The female gull will lay her first egg at anytime during a 24 hour period, but the majority of 2nd and 3rd eggs are laid from midday to evening. The eggs are incubated by both sexes at intervals of two to three hours, and will begin to hatch at around three to four weeks. When the chicks are hatched, they are tended by both parents. For the first four days, they will feed the hatchlings insects and small fish. At 20 days the young will begin to forage for food on their own, feeding on insects and their larvae, although they will still occasionally be fed by the parents, and will not be fully independent until about eight weeks.
The young gulls will stay in the nest until near to full growth, all the while being camoflouged by thick, speckled down. However, because many young gulls will often cannibalise their younger or weaker siblings, it is a rarity for more than one chick to survive.(Time Life, 1976; Skutch, 1976; Felix, 1998; Bent, 1963; Ehrlich, Dobkin & Wheye 1988)
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous .
Lifespan/Longevity
Lifespan of up to 24 years.
Behavior
Mew Gulls will not stray far from land and are known to seek the shore first in the occurrence of stormy weather. The gulls will also advance further inland in large flocks, into agricultural districts, to feast on the exposed worms and larvae after the land has been plowed. Northern gulls will migrate south when breeding season begins. (Bent, 1963)
Food Habits
Mew gulls can be quite opportunistic, which certainly contributes to their adeptness at survival and their great abundance. As an example, the Mew gull, when it is able to get a clam or muscle, will fly over and drop the creature repeatedly on a hard surface until the shell gives way and cracks open. However the Mew gulls food of choice is almost always fish or seafood, which it will catch by dipping down into the water, or simply floating above and waiting for the fish. Worms, insects, mice, berries and grains from farmlands also make up the wide spectrum of food gulls will consume. Many times when food is scarce, gulls will resort to cannibalism, eating a large number of hatchlings and younger birds, which in many gull colonies leads to a high infant mortality rate.
Foods eaten include: cod, herring, worms, insects, berries, grains, crustaceans, clams, mussels and young sea birds.
(Time Life, 1976; Bent, 1963; Harrison, 1983)
Primary Diet:
omnivore .
Animal Foods:
birds; mammals; fish; eggs; carrion ; insects; mollusks; terrestrial worms; aquatic crustaceans.
Plant Foods:
seeds, grains, and nuts; fruit.
Predation
- gulls (Laridae)
- gray foxes (Urocyon cinereoargenteus)
- weasels (Mustela)
- sharks (Chondrichthyes)
Cannibalistic adult gulls will eat eggs and hatchlings. Also, mammals such as foxes and weasels may at times kill more than they can eat at one time (Time Life, 1976; Ehrlich, Dobkin & Wheye 1988)
Ecosystem Roles
Mew Gulls, as with their many relatives, are known as efficient garbage collectors. They scavenge off dead animals washed ashore and human debris left behind, in effect, keeping their habitat somewhat clean. (Time Life, 1976)
Key ways these animals impact their ecosystem:
disperses seeds.
Economic Importance for Humans: Negative
In some areas the gulls become too numerous and cause problems, such as crashing into planes, defecating on buildings and statues, and crowding out other species of birds from their habitats. (Time Life, 1976)
Economic Importance for Humans: Positive
Mew Gulls, along with many other types of gulls, have helped to keep beaches a bit cleaner due to their scavenging nature. This in effect, cuts the cost of maintenance of beaches. (Time Life, 1976)
Conservation Status
IUCN Red List: [link]:
Least Concern.
US Migratory Bird Act: [link]:
Protected.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
State of Michigan List: [link]:
No special status.
In some areas they are protected by law for their esteemed ability to keep beaches and coastal waters relatively clean of natural and human debris. (Time Life, 1976)
For More Information
Find Larus canus information at
Contributors
Alex Steele (author), Fresno City College.
Carl Johansson (editor), Fresno City College.
