The South Georgia Shag is found only on South Georgia Island (where this species has the greatest population), South Sandwich Island, and the South Orkney Islands (Clements 2014).The islands are located in the Antarctic region of the southern Atlantic Ocean, near to both Argentina and the Antarctic Peninsula. This marine bird is also known as the South Georgia Cormorant and has five other synonymous names: Phalacrocorax georgianus, Notocarbo atriceps georgianus, Notocarbo geogianus, Leucocarbo atriceps georgianus, and Leucocarbo geogianus.The species was described by Einar Lönnberg of Sweden in his book “Contributions to the Fauna of South Georgia” in 1906 (Kennedy and Spencer 2014).Of the order Pelecaniformes, the South Georgia Shag is a member of the Phalacrocoracidae family, containing 39 species of cormorants and shags (Shields 2006).Many researchers use the name Phalacrocorax as the only genus within the Phalacrocoracidae family because of the lack of knowledge of these birds.Others have used Phalacrocorax and Leucocarbo as the two major genera, out of seven total genera, within that family (Kennedy and Spencer 2014).There are also discrepancies over whether or not this is a species or a subspecies of Phalacrocorax atriceps (the Imperial Shag) because it too is a blue-eyed shag (Worthy 2011).
The island and marine habitat of the South Georgia Shag remains cold. The terrestrial portion of their habitat is mostly grassland with inlet waterways.Low-lying coastal regions are the breeding ground for these shags.Near the island there are rock stacks offshore while there are natural barriers due to large glaciers on South Georgia Island itself.These birds forage in coastal waters. In general, all shags have a breeding population of 104-105, are between four and five years old when they first reproduce, have an annual survival rate of 85%, have an average clutch of three, and feed on fish and octopus (Croxall 1987).The benthic fish they tend to eat are thriving (Harris et al. 2014).Although both sexes tend to dive to the bottom of the ocean, males tend to eat fish at slightly higher trophic levels (Bearhop et al. 2006).These bottom divers prefer to eat Notothenia, Trematomus, and Champsocephalus (all genera of Cod Icefishes) that have not yet matured and are found in inshore waters and kelp beds.Because of overfishing, they seem to eat mostly Champsocephalus (Croxall 1987).
South Georgia Shags are known for not using the typical cormorant posture of wing-spreading.Wing-spreading could be for feather maintenance, social display, shading the nest, wing drying, and thermoregulation (Cook and Leblanc 2007).Wing-spreading is probably not exhibited in the South Georgia Shag because the Southern Ocean areas are cold year round.In this climate, avoiding wing-spreading reduces heat loss (Cook and Leblanc 2007).The cost of wing-spreading also outweighs the benefits because these birds are still partially wettable and have little fat to keep them warm, along with notoriously low body temperatures.These traits seem to be adaptations to cold weather conditions (Cook and Leblanc 2007).
ADL, or aerobic dive limit, is the dive duration time at which lactate starts to build up in the blood (Butler 2006).Most dives should not exceed the ADL time limit, but in birds the ADL is normally much less then actual recorded dive durations.However, in blue-eyed shags generally, 36% of their dive durations are greater than the ADL.During diving their already low abdominal temperatures plummet even more (Ponganis and Kooyman 2000).Their common diving duration can be <2 minutes or about 4 minutes (bimodal dive pattern), and their maximum dive duration is around 4.6 minutes.They have a shallow and a deep dive pattern where foraging trips last 6-10 hours (Ponganis and Kooyman 2000).Because of the male-biased sexual size dimorphism, males reach greater depths than the females while foraging (Ponganis and Kooyman 2000)and catch larger prey (Bearhop et al. 2006).
During breeding season, the South Georgia shag uses its energy as efficiently as possible.The energy expenditure during any season is mostly due to buoyancy, depending on the depth of their foraging dives.It was found that a larger depth led to a smaller overall body dynamic, or ODBA (Halsey, Shepard, and Wilson 2011).
An Antarctic Treaty that includes the Agreed Measures for the Conservation of Antarctic Flora and Fauna both preserves and conserves all biotic resources south of -60° latitude.No human can kill, capture, or hurt any native bird in this region without a permit (Croxall 1987).Also, there are waste-disposal methods being used to minimize pollution, regulation of introducing non-native species, and rules prohibiting interference with the birds. SPAs (specially protected areas) and SSSIs (sites of special scientific interest) were also instated to protect the birds.Where there are known populations of the blue-eyed shags in the sub-Antarctic region, there are 5 SPAs and 2 SSSIs.Of the 5 SPAs in this region, 1 is at South Georgia Island (Croxall 1987),and both of the SSIs in the region are written in the range of the South Georgia Shag. Also at South Georgia there are areas of special tourist interest where people can visit, while the rest of the island is completely protected from human activities (Croxall 1987).
Marine reserves are a very good idea as well, but because food resources can move in and out of the normal foraging range for these birds, it is difficult to delineate potential areas for reserves.Overall, conservation priorities for the protection of the South Georgia Shag are: creation of both marine and terrestrial resources, non-native species removal, and research focused on the interaction between the shags and their environment (especially their prey) (Croxall 1987).
The South Georgia Shag is a blue-eyed seabird.They exhibit traits that are similar to those of other members of the cormorant family including long bills, white/black/grey/brown plumage, and webbed feet (Kennedy and Spencer 2014).The average adult weighs 2.5 kg (Croxall 1987).Their plumage is hypothesized to be partially wettable, meaning that part of the plumage is hidden from the air.This is similar to the wettable plumage of cormorants in general. They can fly, so they have partially pneumatic bones.Unlike other cormorants, the South Georgia Shag does not display wing-spreading after diving and foraging (Cook and Leblanc 2007).This species also exhibits sexual size dimorphism (where the males are larger then the females; Wearmouth and Sims 2008).They have generally low abdominal body temperatures as well (Cook and Leblanc 2007).
Current threats to L. georgianus are believed to be habitat disturbance/destruction, predation, and competition for food.They inhabit both marine and terrestrial habitats so they must adapt to problems in both. Humans have introduced many non-native vertebrates to the terrestrial landscape.Non-native herbivores, such as reindeer, goats, and sheep, are degrading and destroying the grassland (Croxall 1987).Reindeer have been killed to restore the South Georgia Island’s native ecosystem (Bazilchuk 2013).Rats, cats, and rabbits were all introduced to the South Georgia Island at some point; only the rats survived long-term.Rats killed the eggs and chicks because they are direct predators of these small birds (Croxall 1987).A non-native rat removal project is in progress to remove rats from the island as well (Bazilchuk 2013).
The biggest conservation issue comes from fisheries.They are exceeding the maximum sustainable yield of prey fish, outcompeting the shags for food.The fisheries take the bottom feeding fish, which have been overexploited, so they are now taking the mid-water fish as well.The South Georgia Shag has a high energy cost for foraging, and they are not good at coping with food shortages, so they are highly susceptible to negative effects due to overexploitation of their food sources by commercial fisheries (Croxall 1987).
Leucocarbo a zo ur genad e rummatadur an evned, krouet e 1856 gant an evnoniour gall Charles Lucien Bonaparte (1803-1857).
Pevarzek spesad a ya d'ober ar genad :
a vo kavet e Wikimedia Commons.
Leucocarbo a zo ur genad e rummatadur an evned, krouet e 1856 gant an evnoniour gall Charles Lucien Bonaparte (1803-1857).
Leucocarbo és un gènere d'ocells de la família dels falacrocoràcids (Phalacrocoracidae). Aquests corbs marins són habitualment inclosos al gènere Phalacrocorax.
Aquests ocells es caracteritzen per un anell al voltant de l'ull, de color blau, porpra o vermell. Comparteixen altres característiques com les parts inferiors blanques (almenys en alguns individus) i els peus de color rosa.[1]
Habiten zones fredes de l'hemisferi sud, especialment a prop de la part meridional d'Amèrica del Sud, l'Antàrtida i Nova Zelanda. Moltes són endèmiques d'illes remotes.
Segons la classificació del Congrés Ornitològic Internacional (versió 2.10, 2011), aquest gènere està format per 14 espècies:
Segons la classificació de Clements 6a edició (2009), totes aquestes espècies pertanyen al gènere Phalacrocorax. A més algunes es contemplen com a subespècies d'atriceps.[2]
Leucocarbo és un gènere d'ocells de la família dels falacrocoràcids (Phalacrocoracidae). Aquests corbs marins són habitualment inclosos al gènere Phalacrocorax.
Aquests ocells es caracteritzen per un anell al voltant de l'ull, de color blau, porpra o vermell. Comparteixen altres característiques com les parts inferiors blanques (almenys en alguns individus) i els peus de color rosa.
Habiten zones fredes de l'hemisferi sud, especialment a prop de la part meridional d'Amèrica del Sud, l'Antàrtida i Nova Zelanda. Moltes són endèmiques d'illes remotes.
Leucocarbo is a genus of birds in the family Phalacrocoracidae. Several species within the genus are collectively known as blue-eyed shags. This is a group of closely related cormorant taxa. Many have a blue, purple or red ring around the eye (not a blue iris); other shared features are white underparts (at least in some individuals) and pink feet.[1]
They are found around the colder parts of the Southern Hemisphere, especially near southern South America, Antarctica, and New Zealand. Many are endemic to remote islands. Determining which types are species and which are subspecies of what larger species is problematic; various recent authorities have recognized from 8 to 14 species and have placed them in a variety of genera. The common names are even more confusing, "like myriad footprints criss-crossing in the snow and about as easy to disentangle." Only one common name is given for most species here.[1]
The genus Leucocarbo was introduced in 1856 by the French naturalist Charles Lucien Bonaparte.[2] He did not specify a type species but this was designated as the guanay cormorant by William Ogilvie-Grant in 1898.[3][4] The name Leucocarbo combines the Ancient Greek leukos meaning "white" with the genus name Carbo introduced by Bernard Germain de Lacépède in 1799.[5]
A molecular phylogenetic study published in 2014 found that Leucocarbo is sister to the American cormorants in the genus Nannopterum; the genera split between 6.7 - 8.0 million years ago.[6]
The genus contains 16 species:[7]
Leucocarbo is a genus of birds in the family Phalacrocoracidae. Several species within the genus are collectively known as blue-eyed shags. This is a group of closely related cormorant taxa. Many have a blue, purple or red ring around the eye (not a blue iris); other shared features are white underparts (at least in some individuals) and pink feet.
They are found around the colder parts of the Southern Hemisphere, especially near southern South America, Antarctica, and New Zealand. Many are endemic to remote islands. Determining which types are species and which are subspecies of what larger species is problematic; various recent authorities have recognized from 8 to 14 species and have placed them in a variety of genera. The common names are even more confusing, "like myriad footprints criss-crossing in the snow and about as easy to disentangle." Only one common name is given for most species here.
La bluokulaj tufkormoranoj estas grupo de tre proksime rilataj taksonoj de kormoranoj. Ĉiu havas bluajn, purpurajn aŭ ruĝajn okulringojn (ne blua iriso); aliaj kunhavas karakterojn kiaj blankaj subaj partoj (almenau ĉe kelkaj individuoj) kaj rozkolorajn piedojn.[1]
Ili troviĝas ĉe la plej malvarmaj partoj de la Suda Hemisfero, ĉefe ĉe suda Sudameriko, Antarkto, kaj Novzelando. Multaj estas endemiaj de malproksimaj insuloj. Determini kiuj tipoj estas specioj kaj kiuj estas subspecioj de pli grandaj specioj estas problemiga; variaj ĵusaj fakuloj agnoskis el 8 al 14 speciojn kaj situis ilin en varioj de genroj. La komunaj nomoj estas eĉ pli konfuzaj.
Limigi tiun grupon laŭ Nelson sed atribui specilimojn laŭ HANZAB havigas la jenan speciliston, dividata en du "kompleksoj":
Se Leucocarbo estas konsiderata distinga genro (kio probable postulus disigon de Phalacrocorax), ankaŭ la Guana kormorano apartenus ĉi tien; alternative, Leucocarbo povus etendiĝis al kelkaj amerikaj specioj (kiaj la Nefluga kormorano kaj la Roka tufkormorano).[2]
La bluokulaj tufkormoranoj estas grupo de tre proksime rilataj taksonoj de kormoranoj. Ĉiu havas bluajn, purpurajn aŭ ruĝajn okulringojn (ne blua iriso); aliaj kunhavas karakterojn kiaj blankaj subaj partoj (almenau ĉe kelkaj individuoj) kaj rozkolorajn piedojn.
Leucocarbo es un género de aves suliformes perteneciente a la familia Phalacrocoracidae. Sus especies son conocidas comúnmente como cormoranes de ojos azules. Junto a los géneros Phalacrocorax y Microcarbo conforma la familia Phalacrocoracidae.[1] Son aves acuáticas que capturan peces zambulléndose bajo el agua.
El nombre del género procede de la combinación del término griego leukos «blanco» y carbo, el nombre científico del cormorán grande,[2] en referencia a las manchas blancas que presentan muchos de sus miembros.
Habitan aguas frías a templadas del hemisferio sur, en la Patagonia, y la costa del océano Pacífico de América del Sur, en la Antártida, Nueva Zelanda, e islas subantárticas. Muchos de sus taxones son endémicos de islas remotas.
Todas sus especies tienen un anillo periocular azul, púrpura, o rojo, aunque siempre el iris es azul. Otras características compartidas son las partes inferiores blancas y las patas de color rosa.[3]
A diferencia de la mayoría de las aves acuáticas, sus plumas no son completamente impermeables, por lo que al mojarse, éstas le hacen aumentar de peso, lo que les permite hundirse más y bucear con facilidad. Una vez en tierra, extienden las alas para secarlas. Además, regulan el volumen de sus sacos aéreos.
Se alimentan principalmente de peces que capturan bajo el agua. Se impulsan principalmente con las patas y pueden zambullirse durante más de un minuto, alcanzando una profundidad de unos 10 m. Habitan en aguas marinas cercanas a las costas. Asimismo, ciertas especies presentan también algunas poblaciones totalmente lacustres, las cuales no tienen contacto con el mar. Nidifican en colonias.
Según la clasificación del Congreso ornitológico internacional el género Leucocarbo contiene 15 especies:[4]
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|fechaacceso= requiere |url= (ayuda) Leucocarbo es un género de aves suliformes perteneciente a la familia Phalacrocoracidae. Sus especies son conocidas comúnmente como cormoranes de ojos azules. Junto a los géneros Phalacrocorax y Microcarbo conforma la familia Phalacrocoracidae. Son aves acuáticas que capturan peces zambulléndose bajo el agua.
El nombre del género procede de la combinación del término griego leukos «blanco» y carbo, el nombre científico del cormorán grande, en referencia a las manchas blancas que presentan muchos de sus miembros.
Leucocarbo est un genre d'oiseaux de la famille des Phalacrocoracidae.
Selon la classification du Congrès ornithologique international (version 5.1, 2015)[1] :
Leucocarbo est un genre d'oiseaux de la famille des Phalacrocoracidae.
Leucocarbo Bonaparte, 1856 è un genere di uccelli acquatici della famiglia Phalacrocoracidae.[1]
Comprende le seguenti specie:[1]
Leucocarbo Bonaparte, 1856 è un genere di uccelli acquatici della famiglia Phalacrocoracidae.
Leucocarbo is een geslacht van vogels uit de familie van de aalscholvers (Phalacrocoracidae).[1] De wetenschappelijke naam van het geslacht is voor het eerst geldig gepubliceerd in 1856 door Bonaparte.
Dit is een groep van verwante soorten aalscholvers die vaak ook nog als soorten uit het geslacht Phalacrocorax worden beschreven. Deze soorten komen allemaal voor in het zuiden van de Grote Oceaan en de Subantarctische wateren.
Bijna alle soorten zijn zwart en wit met vooral wit in de bovenvleugeldekveren, een kuifje op de kruin en een blauwe ring om het oog.
De volgende soorten zijn bij het geslacht ingedeeld:[1]
Leucocarbo is een geslacht van vogels uit de familie van de aalscholvers (Phalacrocoracidae). De wetenschappelijke naam van het geslacht is voor het eerst geldig gepubliceerd in 1856 door Bonaparte.
Dit is een groep van verwante soorten aalscholvers die vaak ook nog als soorten uit het geslacht Phalacrocorax worden beschreven. Deze soorten komen allemaal voor in het zuiden van de Grote Oceaan en de Subantarctische wateren.
Bijna alle soorten zijn zwart en wit met vooral wit in de bovenvleugeldekveren, een kuifje op de kruin en een blauwe ring om het oog.
Multimedia w Wikimedia Commons Phalacrocorax – rodzaj ptaka z rodziny kormoranów (Phalacrocoracidae).
Rodzaj obejmuje gatunki występujące na wszystkich kontynentach oprócz obszarów antarktycznych[5].
Długość ciała 55–100 cm; masa ciała 520–4000 g; rozpiętość skrzydeł 90–160 cm[6].
Do rodzaju należą następujące gatunki[9]:
Phalacrocorax – rodzaj ptaka z rodziny kormoranów (Phalacrocoracidae).
Leucocarbo är ett fågelsläkte i familjen skarvar inom ordningen sulfåglar.[1] Det inkluderas ofta i släktet Phalacrocorax.[2] Leucocarbo omfattar här 15 arter med utbredning i västra och södra Sydamerika, på Antarktishalvön samt på öar österut till Nya Zeeland och dess ögrupper:[1][3]
Arterna georgianus, melanogenis, bransfieldensis, nivalis och purpurascens behandlas alla av vissa auktoriteter som underarter till kejsarskarven.
Wikimedia Commons har media som rör Leucocarbo.
Leucocarbo är ett fågelsläkte i familjen skarvar inom ordningen sulfåglar. Det inkluderas ofta i släktet Phalacrocorax. Leucocarbo omfattar här 15 arter med utbredning i västra och södra Sydamerika, på Antarktishalvön samt på öar österut till Nya Zeeland och dess ögrupper:
Guanoskarv (L. bougainvillii) Kejsarskarv (L. atriceps) Sydgeorgisk skarv (L. georgianus) Antarktisskarv (L. bransfieldensis) Heardskarv (L. nivalis) Crozetskarv (L. melanogenis) Macquarieskarv (L. purpurascens) Kerguelenskarv (L. verrucosus) Vårtskarv (L. carunculatus) Otagoskarv (L. chalconotus) Foveauxskarv (L. stewarti) – behandlas ofta som underart till chalconotus Chathamskarv (L. onslowi) Campbellskarv (L. campbelli) Aucklandskarv (L. colensoi) Bountyskarv (L. ranfurlyi)Arterna georgianus, melanogenis, bransfieldensis, nivalis och purpurascens behandlas alla av vissa auktoriteter som underarter till kejsarskarven.
Metne bakınız.
Dış bağlantılar
Wikimedia Commons'ta Leucocarbo ile ilgili çoklu ortam belgeleri bulunur. 
Wikispecies'te Leucocarbo ile ilgili detaylı taksonomi bilgileri bulunur. Leucocarbo, karabatakgiller (Phalacrocoracidae) familyasından bir kuş cinsidir. Önceleri Phalacrocorax cinsinin içinde sınıflandırılmaktaydı.
Leucocarbo, karabatakgiller (Phalacrocoracidae) familyasından bir kuş cinsidir. Önceleri Phalacrocorax cinsinin içinde sınıflandırılmaktaydı.
Leucocarbo là một chi chim thuộc họ Phalacrocoracidae,[1]. Chúng đôi khi được xếp như một thành phần của chi Phalacrocorax
Một số tài liệu xếp chi Leucocarbo gồm 14 loài[2]. Số khác xếp thành 10 loài[3]
Trong trường hợp sau, các phân loài L. albiventer được xếp chung vào loài L. atriceps, như phân loài L. albiventer albiventer sẽ trở thành phân loài L. atriceps albiventer.
Leucocarbo là một chi chim thuộc họ Phalacrocoracidae,. Chúng đôi khi được xếp như một thành phần của chi Phalacrocorax
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