The bird commonly referred to as the Black-headed Gull, or also called as Larus Argentatus is the second largest typical gulls of Finland, then the Atlantic Gull. Adults have bluish-gray turn, with their wingtips marked with white spots (like the gray gulls). Their head and underparts are white.
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Description of the herring gull
The feathers of the herring gull, head, neck and back of young gulls are generally grayish-brown, with yellowish edges and spots. The abdomen is grayish white with many brownish spots and streaks. Their wing feathers are dark brown (compared to the almost black feathers of young Atlantic terns), and their inner primates form a transparent adhesive (absent in young Atlantic terns).
The Atlantic kittiwake has four stages in its life cycle and many different plumages. From its second winter onwards, it has a gray back and yellow iris. Older gulls have pink legs, while younger gulls have brownish-gray legs. The iris is light yellow in adults and dark brown to light yellow in young birds.
Herring gulls often fly high in the sky in V-shaped formations, between the places where they roost and where they feed, and such flocks may even resemble bands of cranes. The bill of mature birds is yellow with a lighter tip, and a red spot on the underside of the upperparts, which appears during their third winter. Young birds have a dark reddish count.
In Finland, you can see two closely related species, the Caspian Gull (Larus cachimans) and the Yellow-legged Gull (Larus michahellis), but identification of these birds is challenging and requires excellent viewing conditions. Only adult Yellow-legged Gulls have yellow legs.
Characteristics
This species of gull, has an average size with respect to other gulls, up to 70 cm in length and up to 150 wing tips, reaching a kilo and a half in weight. It is white or gray, black at the end of the wings, and its main characteristics are the pink legs and the yellow cuff with a red subterminal space on the lower jaw. Meet the Sooty Bunting.
Adults not appreciated for sexual dimorphism are white on the head, tail and ventral areas, while the rest is grayish; The main references are white-tipped and black, clarifying the inner wing; Another white subterminal spot is also characteristic of the second outermost primary wing.
During the conception period, they have a grayish line on the neck and sides of the chest. Juveniles, unlike adults, with a blackish bill and a pinkish spot on the underside; Their plumage is grayish brown, with grayish lines on the body of the body. The wings have a lighter position on the inner main shoulders, while the rest and the secondary are black. The tail is white The individuals found in the Bay of Biscay belong to the subterranean Argentine.
Size 53-67 cm; wingspan 120-155 cm. Five subspecies are recognized: L. a. argentatus, L. a. argenteus, L. a. smithsonianus, L. a. vegae and L. a. mongolicus, which basically differ in size, proportions, wing shading and backward, as well as the pattern of the primary penalties.
The herring gull is a large gull characterized by the light gray tone of the upperparts, darker on the razvegae. Compared to other large gulls, it is characterized by a strong expression, with a more angular head, a powerful beak and shorter wings that give a corpulent appearance when perched.
The adult has a white underside, tail and head, while the wings and back are light gray with black wingtips with small white spots. It has a yellow bill with a red spot on the distal part of the mandible. The lower extremities are pink, with bluish tones in the “birulae” and yellow in the “omissus” form. The eye is pale yellow, the eye ring is pink.
In the summer (January-September), it shows the brightest bare parts. In the winter (September to February), the head and neck are covered with a variable amount of a more intense form in the ear and around the eye brown striped thin and bare parts become dulled and may present dark beak marking.
The juvenile has grayish coloration in general, being whiter on the forehead and nape. The feathers on the back have whitish margins with black centers in the shape of an oak leaf. The tips of the wings are black, as is the end of the tail whose base is white with an intense brown exploration. The eye is brown, the bill black, while the legs are gray or flesh-colored. In subspeciesmithsonianus, the general coloration is chocolate brown and the tail is almost completely dark.
Feeding of the herring gull
It is an onivorous and highly opportunistic species, exploring the most numerous resources at all times. Its diet includes mainly fish, but also invertebrates, chicks and eggs of other birds, as well as meat and rodents. Feeding techniques in the water are dipping in the air or on the surface of the water, while on land he goes hunting whatever is left in sight. He also goes to garbage dumps and follows ships to feed on discards.
The gull argentatus argentea argentatus is quite common, although varied, although it is a bird that takes advantage of the available resources, its diet consists mainly of food of animal origin.It has been reported to feed on crustaceans, clams and mussels (Mytillus edulis), fish such as capelin (Mallotus villosus), eggs of other birds such as the common guillemot (Uria aalgae) or with other gull eggs. (see article: (tixagag_16) Lanius Collurio ).
Their diet has changed in some geographic areas, and due to environmental changes and human intervention they can be introduced to garbage in their diet, including human food debris and plastic and other human waste. In fishing areas, they also tend to feed on garbage discarded by boats. Its diet may also contain plant parts (roots, fruits, seeds, tubers, among others).
Habitat
The herring gull, usually lives on beaches, like most of these gulls in rock formations, gathered in ports and estuaries. It has a very varied diet, feeding on fish, mollusks, small birds, eggs, carcasses … It has a clumsy flight in appearance but powerful, allowing it to attack other birds in flights. You can make brief dives in search of food.
The argentine gull argentatus is classified in the category of “least concern” of the red list of the UUCN (International Union for Conservation of Nature). The main threats to the silver gull involve man as a protagonist in the pollution of the coasts, lakes or bodies of water where this bird lives, especially by oil. It is currently protected by the African-Eurasian Waterbird Agreement.
Breeding
It uses as breeding sites cliffs and coastal islands, beaches, gravel, lakes and marshes, and even urban and port structures, forming monospecific colonies. There are known cases of hybridization with Shadow-rumped Gull, Yellow-legged Gull, Bering’s Gull and Hyperboreal Gabion. Days and hens will fly 40 to 45 days after hatching. They reach sexual maturity in their fourth year of life, showing high philopatry for their place of birth.
L. argentatus like all other birds, reproduces through eggs. The nuptial procession involves the approach of the female to the male, erect posture, emission of long sounds and feeding of the male to the female. It prefers to nest in colonies in bare rocky places with little vegetation or to build nests with grasses and branches, on the top or on the ground.
The appearance of the silvery gold varies according to its life span. Thus, the adult has the head and ventral part of the body fluid; its wings and part of the back are light gray, hence the name “argentatus” which refers to silver; The wings are black with white spots; the bill is yellow tones with a red spot on the lower jaw; their eyes are yellow. At the same time, juveniles are darker in color with shades ranging from brown and gray, with a black and brown upper eye.
It takes about four years for the argentate gull argentatus to reach sexual maturity and thus the characteristic adult feathered suit. They are measles gender dimorphism in the size of females and males, which males are larger than females. The Silver Gold is a moving bird with a characteristic disturbing song when it feels threatened.
The gulls normally return to the same colony to breed for several years, and nest in the same place as it did previous seasons, it was shown to occur only changes this behavior when there was hatching success or survival of the offspring.
