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Sea Gulls
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari. They are most closely related to the terns and skimmers and only distantly related to auks, and even more distantly to waders. Until the 21st century, most gulls were placed in the genus ''Larus'', but that arrangement is now considered polyphyletic, leading to the resurrection of several genera. An older name for gulls is mews, which is cognate with German ''Möwe'', Danish ''måge'', Swedish ''mås'', Dutch ''meeuw'', Norwegian ''måke''/''måse'' and French ''mouette'', and can still be found in certain regional dialects. Gulls are typically medium to large in size, usually grey or white, often with black markings on the head or wings. They typically have harsh wailing or squawking calls; stout, longish bills; and webbed feet. Most gulls are ground-nesting carnivores which take live food or scavenge opportunistically, particularly the ''Larus'' species. Live food often includes crustac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Oligocene
The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian Stage. Name The stage is named after the small river Rupel in Belgium, a tributary to the Scheldt. The Belgian Rupel Group derives its name from the same source. The name Rupelian was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The separation between the group and the stage was made in the second half of the 20th century, when stratigraphers saw the need to distinguish between lithostratigraphic and chronostratigraphic names. Stratigraphic definition The base of the Rupelian Stage (which is also the base of the Oligocene Series) is at the extinction of the foraminiferan genus ''Hantkenina''. An official GSSP for the base of the Rupelian has been assigned in 1992 (Massignano, Italy). The transi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobbing (animal Behavior)
Mobbing in animals is an antipredator adaptation in which individuals of prey species mob a predator by cooperatively attacking or harassing it, usually to protect their offspring. A simple definition of mobbing is an assemblage of individuals around a potentially dangerous predator. This is most frequently seen in birds, though it is also known to occur in many other animals such as the meerkat and some bovines. While mobbing has evolved independently in many species, it only tends to be present in those whose young are frequently preyed upon. This behavior may complement cryptic adaptations in the offspring themselves, such as camouflage and hiding. Mobbing calls may be used to summon nearby individuals to cooperate in the attack. Konrad Lorenz, in his book ''On Aggression'' (1966), attributed mobbing among birds and animals to instincts rooted in the Darwinian struggle to survive. In his view, humans are subject to similar innate impulses but capable of bringing them under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Gull
The lava gull (''Leucophaeus fuliginosus''), also known as the dusky gull, is a medium-sized gull and a member of the "hooded gull" group. It is most closely related to the Laughing gull and Franklin's gull and is the rarest gull in the world. It is endemic to the Galapagos Islands. Taxonomy and systematics First described by John Gould in 1841 from a specimen collected on Santiago Island in the Galápagos. The species is sometimes placed in the genus ''Larus''. It is possibly closely related to the laughing gull. Description The lava gull is a distinctive gull, and weighs . The adult plumage consists of a sooty brown to black head, which unlike other dark hooded gulls doesn't vary by season. The wings are dark gray with a contrasting white line on the leading edge, thought to play a function in displays and camouflage. Its dark gray body contrasts with a paler gray belly. The uppertail is white and grey lower down. The bill and legs are black, and the inside of the mouth is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ivory Gull
The ivory gull (''Pagophila eburnea'') is a small gull, the only species in the genus ''Pagophila''. It breeds in the high Arctic and has a circumpolar distribution through Greenland, northernmost North America, and Eurasia. Taxonomy The ivory gull was initially described by Constantine Phipps, 2nd Baron Mulgrave in 1774 as ''Larus eburneus'' from a specimen collected on Spitsbergen during his 1773 expedition towards the North Pole. Johann Jakob Kaup later recognized the unique traits of the ivory gull and gave it a monotypic genus, ''Pagophila'', in 1829. Johan Ernst Gunnerus later gave the species a new specific name, ''Pagophila alba''. The genus name ''Pagophila'' is from Ancient Greek ''pagos'', "sea-ice", and ''philos'', "-loving", and specific ''eburnea'' is Latin for "ivory-coloured", from ''ebur'', "ivory". Today some authors consider the ivory gull not deserving of its monotypic genus, instead choosing to merge it, along with the other monotypic gulls, back into '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, there can be different colour morphs. The placement of feathers on a bird is not haphazard, but rather emerge in organized, overlapping rows and groups, and these are known by standardized names. Most birds moult twice a year, resulting in a breeding or ''nuptial plumage'' and a ''basic plumage''. Many ducks and some other species such as the red junglefowl have males wearing a bright nuptial plumage while breeding and a drab ''eclipse plumage'' for some months afterward. The painted bunting's juveniles have two inserted moults in their first autumn, each yielding plumage like an adult female. The first starts a few days after fledging replacing the ''juvenile plumage'' with an ''auxiliary formative plumage''; the second a month or so l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross's Gull
Ross's gull (''Rhodostethia rosea'') is a small gull, the only species in its genus, although it has been suggested it should be moved to the genus '' Hydrocoloeus'', which otherwise only includes the little gull. This bird is named after the British explorer James Clark Ross. Its breeding grounds were first discovered in 1905 by Sergei Aleksandrovich Buturlin near the village of Pokhodsk in North-Eastern Yakutia, while visiting the area as a judge. The genus name ''Rhodostethia'' is from Ancient Greek ''rhodon'', "rose", and ''stethos'', "breast". The specific ''rosea'' is Latin for "rose-coloured". Description This small bird is similar in size and some plumage characteristics to the little gull. It is slightly larger and longer winged than the little gull species, and has more-pointed wings and a wedge-shaped tail. Its legs are red. Summer adults are pale grey above and white below, with a pink flush to the breast, and a neat black neck ring. In winter, the breast tints and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swallow-tailed Gull
The swallow-tailed gull (''Creagrus furcatus'') is an equatorial seabird in the gull family, Laridae. It is the only species in the genus ''Creagrus'', which derives from the Latin ''Creagra'' and the Greek ''kreourgos'' which means butcher, also from ''kreas'', meat; according to Jobling it would mean "hook for meat" referring to the hooked bill of this species. It was first described by French naturalist and surgeon Adolphe-Simon Neboux in 1846. Its scientific name is originally derived from the Greek word for gull, "Glaros" and via Latin ''Larus'', "gull" and ''furca'' "two-tined fork". It spends most of its life flying and hunting over the open ocean. The main breeding location is in the Galápagos Islands, particularly the rocky shores and cliffs of Hood, Tower and Wolf Islands, with lower numbers on most of the other islands. It is more common on the eastern islands where the water is warmer. It is the only fully nocturnal gull and seabird in the world, preying on squid a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sabine's Gull
Sabine's gull ( ) (''Xema sabini'') also known as the fork-tailed gull or xeme, is a small gull. It is the only species placed in the genus ''Xema''. It breeds in colonies on coasts and tundra, laying two or three spotted olive-brown eggs in a ground nest lined with grass. Sabine's gull is pelagic outside the breeding season. It takes a wide variety of mainly animal food, and will eat any suitable small prey. Taxonomy Sabine's gull was formally described in 1819 by the naturalist Joseph Sabine under the binomial name ''Larus sabini''. Sabine based his description on specimens that had been collected by his brother Captain Edward Sabine who had accompanied Captain John Ross's on a voyage to look for the Northwest Passage. The birds were found breeding on low lying islands off the west coast of Greenland in July 1818. Sabine's gull is now the only species placed in the genus ''Xema'' that was introduced in 1819 by the zoologist William Leach in an appendix to Ross's account of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Black-backed Gull
The great black-backed gull (''Larus marinus'') is the largest member of the gull family. Described by the Cornell Lab of Ornithology as "the king of the Atlantic waterfront", it is a very aggressive hunter, pirate, and scavenger. It breeds on the European and North American coasts and islands of the North Atlantic and is fairly sedentary, though some move farther south or inland to large lakes or reservoirs. The adult great black-backed gull has a white head, neck and underparts, dark grey wings and back, pink legs and yellow bill. Taxonomy The great black-backed gull was one of the many species originally described by Carl Linnaeus in his 1758 10th edition of ''Systema Naturae'', and it still bears its original name of ''Larus marinus''. The scientific name is from Latin. ''Larus'' appears to have referred to a gull or other large seabird. The specific name ''marinus'' means "marine", or when taken together, "sea gull". This predates Linnean taxonomy, as it had been called ''L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Gull
The little gull (''Hydrocoloeus minutus'' or ''Larus minutus''), is a small gull that breeds in northern Europe and across the Palearctic. The genus name ''Hydrocoloeus'' is from Ancient Greek , "water", and , a sort of web-footed bird. The specific is Latin for "small". It also has small colonies in parts of southern Canada. It is migratory, wintering on coasts in western Europe, the Mediterranean and (in small numbers) the northeast United States; in recent years non-breeding birds have summered in western Europe in increasing numbers and in 2016 they successfully nested for the first time in Great Britain at the Royal Society for the Protection of Birds reserve at Loch of Strathbeg reserve in Aberdeenshire. As is the case with many gulls, it has traditionally been placed in the genus ''Larus''. It is the only member of the genus ''Hydrocoloeus'', although it has been suggested that Ross's gull also should be included in this genus. This species breeds colonially on freshwate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larus Pacificus Bruny Island
''Larus'' is a large genus of gulls with worldwide distribution (by far the greatest species diversity is in the Northern Hemisphere). Many of its species are abundant and well-known birds in their ranges. Until about 2005–2007, most gulls were placed in this genus, but this arrangement is now known to be polyphyletic, leading to the resurrection of the genera ''Ichthyaetus'', ''Chroicocephalus'', ''Leucophaeus'', and '' Hydrocoloeus'' (this last had been recognized more often than the other genera) for several species traditionally included in ''Larus''. They are in general medium to large birds, typically grey or white, often with black markings on their heads or wings. They have stout, longish bills and webbed feet. The taxonomy of the large gulls in the herring and lesser black-backed complex is very complicated, with different authorities recognising between two and eight species. Taxonomy The genus ''Larus'' was introduced in 1758 by the Swedish naturalist Carl Linn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kleptoparasitism
Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when food is scarce or when victims are abundant. Many kleptoparasites are arthropods, especially bees and wasps, but including some true flies, dung beetles, bugs, and spiders. Cuckoo bees are specialized kleptoparasites which lay their eggs either on the pollen masses made by other bees, or on the insect hosts of parasitoid wasps. They are an instance of Emery's rule, which states that insect social parasites tend to be closely related to their hosts. The behavior occurs, too, in vertebrates including birds such as skuas, which persistently chase other seabirds until they disgorge their food, and carnivorous mammals such as spotted hyenas and lions. Other species opportunistically indulge in kleptoparasitism. Strategy Kleptoparasitism is a fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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