White-eyed Gull
Encyclopedia
The White-eyed Gull is a small gull
which is endemic
to the Red Sea
. Its closest relative is the Sooty Gull
. It is one of the world's rarest gulls, with a population of just 4,000 - 6,500 pairs. The species is classed as Near Threatened
by the IUCN; human
pressure and oil
pollution
are deemed the major threats. As is the case with many gulls, it has traditionally been placed in the genus
Larus
.
hood in breeding plumage
, which extends down onto the upper throat, and on the neck-sides is bordered below by a narrow white
bar. The upperparts and inner upperwings are medium-dark grey
; the breast is mid-grey but the rest of the underparts are white. The secondaries are black with a white trailing edge, and the primaries are black. The underwing is dark, and the tail white. Adults in non-breeding plumage are similar, but the hood is flecked white small white spots.
The White-eyed Gull acquires adult plumage at two to three years of age. Juvenile birds have a very different plumage - chocolate brown
on the head, neck and breast, and with brown, broadly pale-fringed, feather
s to the upperparts and upperwings, and a black tail. In their first Winter, birds acquire greyer feathering on their head, breast and upperparts; the second-winter plumage is closer to that of the adult, but lacking the hood.
A distinctive feature of White-eyed Gull at all ages is its long slender bill
. This is black in younger birds, but in adults it is deep red
with a black tip. The legs are yellow
– dullest in younger birds, brightest in breeding plumaged adults. The eye itself is not white; the bird takes its name from white eye-crescents, which are present at all ages.
, in the Red Sea from July to September. For the rest of the year it occurs throughout the Red Sea, with some birds travelling to Oman
and Somalia
.
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
which is endemic
Endemism in birds
An endemic bird area is a region of the world that contains two or more restricted-range species, while a "secondary area" contains one or more restricted-range species. Both terms were devised by Birdlife International....
to the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
. Its closest relative is the Sooty Gull
Sooty Gull
The Sooty Gull is a species of gull in the Laridae family.It is found in Bahrain, Djibouti, Egypt, Eritrea, India, Iran, Israel, Jordan, Kenya, Lebanon, Maldives, Mozambique, Oman, Pakistan, Qatar, Saudi Arabia, Somalia, Sri Lanka, Sudan, Tanzania, United Arab Emirates, and Yemen...
. It is one of the world's rarest gulls, with a population of just 4,000 - 6,500 pairs. The species is classed as Near Threatened
Near Threatened
Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...
by the IUCN; human
Human
Humans are the only living species in the Homo genus...
pressure and oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
are deemed the major threats. As is the case with many gulls, it has traditionally been placed in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Larus
Larus
Larus is a large genus of gulls with worldwide distribution . Many of its species are abundant and well-known birds in their ranges...
.
Morphology
Adult White-eyed Gulls have a blackBlack
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
hood in breeding plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
, which extends down onto the upper throat, and on the neck-sides is bordered below by a narrow white
White
White is a color, the perception of which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in nearly equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness.White light can be...
bar. The upperparts and inner upperwings are medium-dark grey
Grey
Grey or gray is an achromatic or neutral color.Complementary colors are defined to mix to grey, either additively or subtractively, and many color models place complements opposite each other in a color wheel. To produce grey in RGB displays, the R, G, and B primary light sources are combined in...
; the breast is mid-grey but the rest of the underparts are white. The secondaries are black with a white trailing edge, and the primaries are black. The underwing is dark, and the tail white. Adults in non-breeding plumage are similar, but the hood is flecked white small white spots.
The White-eyed Gull acquires adult plumage at two to three years of age. Juvenile birds have a very different plumage - chocolate brown
Brown
Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color....
on the head, neck and breast, and with brown, broadly pale-fringed, feather
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
s to the upperparts and upperwings, and a black tail. In their first Winter, birds acquire greyer feathering on their head, breast and upperparts; the second-winter plumage is closer to that of the adult, but lacking the hood.
A distinctive feature of White-eyed Gull at all ages is its long slender bill
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
. This is black in younger birds, but in adults it is deep red
Red
Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
with a black tip. The legs are yellow
Yellow
Yellow is the color evoked by light that stimulates both the L and M cone cells of the retina about equally, with no significant stimulation of the S cone cells. Light with a wavelength of 570–590 nm is yellow, as is light with a suitable mixture of red and green...
– dullest in younger birds, brightest in breeding plumaged adults. The eye itself is not white; the bird takes its name from white eye-crescents, which are present at all ages.
Distribution
The White-eyed Gull breeds on inshore islands with rocks and sandy beaches, such as the Siyal IslandsSiyal Islands
The Siyal Islands are a group of islands off the coast of northeastern Africa, located in the Red Sea. The islands are located in the Halayeb Triangle, which is claimed by both Sudan and Egypt, as part of an ongoing border dispute. Since the 1990s, the islands have been occupied by Egypt, and so...
, in the Red Sea from July to September. For the rest of the year it occurs throughout the Red Sea, with some birds travelling to Oman
Oman
Oman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...
and Somalia
Somalia
Somalia , officially the Somali Republic and formerly known as the Somali Democratic Republic under Socialist rule, is a country located in the Horn of Africa. Since the outbreak of the Somali Civil War in 1991 there has been no central government control over most of the country's territory...
.