The Kent Plateau ( 80°44′S 157°50′E / 80.733°S 157.833°E / -80.733; 157.833 ( Kent Plateau ) ) is an ice-covered plateau in the northern extreme of the Churchill Mountains of Antarctica.
56-477: Kent Plateau was named by the Advisory Committee on Antarctic Names for Commander Donald F. Kent, U.S. Navy , logistics officer to Admiral Dufek at the outset of U.S. Navy Operation Deep Freeze I , 1955–56. The Kent Plateau is an ice-covered plateau, 12 miles (19 km) long and 4 miles (6.4 km) wide, extending northward from Mount Egerton and Kiwi Pass to the vicinity of Mount Hamilton. The plateau
112-854: A claimed territory selected for large size and cursoriality in Tertiary ancestors of ratites. Temperate rainforests dried out throughout the Miocene and transformed into semiarid deserts, causing habitats to be widely spread across the growingly disparate landmasses. Cursoriality was an economic means of traveling long distances to acquire food that was usually low-lying vegetation, more easily accessed by walking. Traces of these events are reflected in ratite distribution throughout semiarid grasslands and deserts today. Gigantism and flightlessness in birds are almost exclusively correlated due to islands lacking mammalian or reptilian predators and competition. However, ratites occupy environments that are mostly occupied by
168-412: A diverse number of mammals. It is thought that they first originated through allopatric speciation caused by breakup of the supercontinent Gondwana . However, later evidence suggests this hypothesis first proposed by Joel Cracraft in 1974 is incorrect. Rather ratites arrived in their respective locations via a flighted ancestor and lost the ability to fly multiple times within the lineage. Gigantism
224-502: A limited number of times per year. High parental involvement denotes the necessity for choosing a reliable mate. In a climatically stable habitat providing year-round food supply, a male's claimed territory signals to females the abundance of resources readily available to her and her offspring. Male size also indicates his protective abilities. Similar to the emperor penguin, male ratites incubate and protect their offspring anywhere between 85 and 92 days while females feed. They can go up to
280-621: A member of the USARP parties which made glaciological and geophysical studies on the Ross Ice Shelf, 1961–62 and 1962-63. 80°41′S 157°40′E / 80.683°S 157.667°E / -80.683; 157.667 . A rugged Y-shaped massif which rises to 1,860 metres (6,100 ft) on the south side of Byrd Glacier in Antarctica. It stands between Brecher Glacier and Twombley Glacier , two southern tributaries to Byrd Glacier. The massif
336-462: A more efficient use of energy in adulthood. The name "ratite" comes from the Latin ratis , raft, a vessel with no keel . Their flat sternum is distinct from the typical sternum of flighted birds because it lacks a keel, like a raft. This structure is the place where flight muscles attach and thus allow for powered flight. However, ratite anatomy presents other primitive characters meant for flight, such as
392-554: A parachute apparatus to help the bird slow down. Wings are hypothesized to have played a role in sexual selection in early ancestral ratites and were thus maintained. This can be seen today in both the rheas and ostriches. These ratites utilize their wings extensively for courtship and displays to other males. Sexual selection also influences the maintenance of large body size, which discourages flight. The large size of ratites leads to greater access to mates and higher reproductive success . Ratites and tinamous are monogamous and mate only
448-416: A week without eating and survive only off fat stores. The emu has been documented fasting for as long as 56 days. If no continued pressures warrant the energy expenditure to maintain the structures of flight, selection will tend towards these other traits. In penguins , wing structure is maintained for use in locomotion underwater. Penguins evolved their wing structure to become more efficient underwater at
504-589: Is 12 kilometres (7.5 mi) east south east of Roberts Pike and overlooks Couzens Bay due east. It was named in honor of Roderick Carr , a member of Shackleton's Expedition of 1914–17. Advisory Committee on Antarctic Names The Advisory Committee on Antarctic Names ( ACAN or US-ACAN ) is an advisory committee of the United States Board on Geographic Names responsible for recommending commemorative names for features in Antarctica . The committee
560-416: Is likely because penguins have well-developed pectoral muscles for hunting and diving in the water. For ground-feeding birds, a cursorial lifestyle is more economical and allows for easier access to dietary requirements. Flying birds have different wing and feather structures that make flying easier, while flightless birds' wing structures are well adapted to their environment and activities, such as diving in
616-411: Is not a requirement for flightlessness. The kiwi do not exhibit gigantism, along with tinamous , even though they coexisted with the moa and rheas that both exhibit gigantism. This could be the result of different ancestral flighted birds arrival or because of competitive exclusion. The first flightless bird to arrive in each environment utilized the large flightless herbivore or omnivore niche, forcing
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#1732858732286672-431: Is often why flightlessness coincides with body mass. By reducing large pectoral muscles that require a significant amount of overall metabolic energy, ratites decrease their basal metabolic rate and conserve energy. A study looking at the basal rates of birds found a significant correlation between low basal rate and pectoral muscle mass in kiwis. On the contrary, flightless penguins exhibit an intermediate basal rate. This
728-456: Is on the west of a ridge of mountains that runs north from Mount Durnford, dips at Kiwi Pass, then continues north from Mount Moa to Mount Hamilton along the east edge of the plateau. To the west of the plateau along the southeast edge of the Byrd Glacier there is a chain of mountains broken by glaciers that flow down from the plateau region to Byrd Glacier. Several short glaciers run down from
784-485: Is that until the arrival of humans roughly a thousand years ago, there were no large mammalian land predators in New Zealand; the main predators of flightless birds were larger birds. Ratites belong to the superorder Palaeognathae , which include the volant tinamou , and are believed to have evolved flightlessness independently multiple times within their own group. Some birds evolved flightlessness in response to
840-543: The Advisory Committee on Antarctic Names is suggestive of the appearance of the peaks. Nearby features to the west and north, along the southern edge of the Byrd Glacier, include from southwest to northeast, Keating Massif, Mount Fries, Zeller Glacier, Mount Rainbow, Sefton Glacier, the Rundle Peaks, Brecher Glacier, Mandarich Massif, Twombley Glacier, Blake Massif, Lowry Massif, Mount Tuatara, Judith Glacier, Mount Tadpole,
896-639: The Holocene (no more than 11,000 years ago). Extinct species are indicated with a cross (†). A number of species suspected, but not confirmed to be flightless, are also included here. Longer-extinct groups of flightless birds include the Cretaceous patagopterygiformes , hesperornithids , the Cenozoic phorusrhacids ("terror birds") and related bathornithids , the unrelated eogruids , geranoidids , gastornithiforms , and dromornithids (mihirungs or "demon ducks"), and
952-487: The domestic chicken and domestic duck , have lost the ability to fly for extended periods, although their ancestral species, the red junglefowl and mallard , respectively, are capable of extended flight. A few particularly bred birds, such as the Broad Breasted White turkey , have become totally flightless as a result of selective breeding ; the birds were bred to grow massive breast meat that weighs too much for
1008-610: The Deputy Secretary responsible for Multi Lateral Affairs, which included the Legal and Antarctic Divisions. Later, as the Deputy Secretary responsible for Corporate Affairs, he retained authority for the Antarctic Policy Unit, at a time of considerable changes to the organizational structure of New Zealand Antarctic institutions from 1985 through to 1993. He provided much of the intellectual input behind New Zealand's work leading to
1064-450: The Interior is in charge of formally appointing the members of the committee. [REDACTED] This article incorporates public domain material from "Advisory Committee on Antarctic Names" . Geographic Names Information System . United States Geological Survey . Flightless bird Flightless birds are birds that cannot fly . They have, through evolution , lost
1120-471: The Miscast Nunataks and Couzens Saddle. Roberts Pike and Carr Crest are isolated features to the east of Lowry Massif. 81°00′00″N 156°34′00″E / 81°N 156.5666667°E / 81; 156.5666667 . A rugged mainly ice-covered massif, 20 kilometres (12 mi) long, rising to approximately 2,370 metres (7,780 ft), and lying northwest. It is located at the southern edge of
1176-598: The Northern Party of the NZGSAE (1960–61) who used the pass in crossing these mountains. Kiwi is a familiar nickname for New Zealanders. Not: Kiwi Saddle. 80°46′S 157°57′E / 80.767°S 157.950°E / -80.767; 157.950 . A mountain rising above 2,000 metres (6,600 ft) at the northern end of the Churchill Mountains. Located above Kiwi Pass and at the southern end of Kent Plateau, it
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#17328587322861232-894: The U.S. Weather Bureau, a member of the Little America V winter party, 1956. 80°42′S 157°28′E / 80.700°S 157.467°E / -80.700; 157.467 . A broad glacier 5 nautical miles (9 km) long in the north Churchill Mountains that flows north between the Rundle Peaks and Mandarich Massif into Byrd Glacier . It was named after Henry H. Brecher of the Byrd Polar Research Center , Ohio State University ; he conducted Antarctic glaciological investigations for over 30 years, 1960–95, including determinations of surface velocities and elevations on Byrd Glacier. 80°29′S 158°49′E / 80.483°S 158.817°E / -80.483; 158.817 . Glacier about 9 miles (14 km) long, flowing from
1288-515: The ability to fly. There are over 60 extant species, including the well-known ratites ( ostriches , emus , cassowaries , rheas , and kiwis ) and penguins . The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird in general, is the common ostrich (2.7 m, 156 kg). Many domesticated birds, such as
1344-413: The ability to fly. They are, however, weak fliers and are incapable of traveling long distances by air. Although selection pressure for flight was largely absent, the wing structure has not been lost except in the New Zealand moas. Ostriches are the fastest running birds in the world and emus have been documented running 50 km/h. At these high speeds, wings are necessary for balance and serving as
1400-404: The absence of predators, for example on oceanic islands . Incongruences between ratite phylogeny and Gondwana geological history indicate the presence of ratites in their current locations is the result of a secondary invasion by flying birds. It remains possible that the most recent common ancestor of ratites was flightless and the tinamou regained the ability to fly. However, it is believed that
1456-670: The adoption of the Environment Protocol. 80°57′S 156°36′E / 80.950°S 156.600°E / -80.950; 156.600 A prominent peak, 1,985 metres (6,512 ft) high, standing just south of the mouth of Zeller Glacier and being one of the westernmost summits along the south wall of Byrd Glacier. Named by US-ACAN for Robert H. Fries, aurora scientist at the South Pole Station, 1963. 80°54′S 156°55′E / 80.900°S 156.917°E / -80.900; 156.917 . A peak, 2,050 m, along
1512-704: The bird's wings to support in flight. Flightlessness has evolved in many different birds independently, demonstrating repeated convergent evolution. There were families of flightless birds, such as the now-extinct Phorusrhacidae , that evolved to be powerful terrestrial predators. Taking this to a greater extreme, the terror birds (and their relatives the bathornithids ), eogruids , geranoidids , gastornithiforms , and dromornithids (all extinct) all evolved similar body shapes – long legs, long necks and big heads – but none of them were closely related. Furthermore, they also share traits of being giant, flightless birds with vestigial wings, long legs, and long necks with some of
1568-598: The continent, in consultation with other national nomenclature bodies where appropriate, as defined by the Antarctic Treaty System . The research and staff support for the ACAN is provided by the United States Geological Survey . ACAN has a published policy on naming, based on priority of application, appropriateness, and the extent to which usage has become established. The United States Secretary of
1624-453: The cost of their efficiency in the air. The only known species of flightless bird in which wings completely disappeared was the gigantic, herbivorous moa of New Zealand , hunted to extinction by humans by the 15th century. In moa, the entire pectoral girdle is reduced to a paired scapulocoracoid , which is the size of a finger. Many flightless birds are extinct ; this list shows species that are either still extant or became extinct in
1680-632: The east edge of Kent Plateau, 7 miles (11 km) south of Mount Tuatara. Discovered by the BrNAE (1901–04) and named for Admiral Sir Richard Vesey Hamilton, who served on Arctic voyages (1850–54) and was a member of the Ship Committee for this expedition. 80°42′S 158°36′E / 80.700°S 158.600°E / -80.700; 158.600 ). Two rounded peaks, or nunataks , which rise to 1,391 metres (4,564 ft) 3 nautical miles (6 km) southeast of Mount Hamilton. The allusive name given by
1736-827: The end of the ridge extending west from Mount Egerton. The feature is 6 nautical miles (11 km) west of the Mount Egerton summit. Mount Morse was named by the Advisory Committee on Antarctic Names after Robert M. Morse of the Department of Physics, University of Wisconsin , a United States Antarctic Program principal investigator from 1989 to 2002, including research relating to the Antarctic Muon And Neutrino Detector Array near South Pole Station . 80°48′S 158°00′E / 80.800°S 158.000°E / -80.800; 158.000 . A high pass immediately northeast of Mount Egerton. Named by
Kent Plateau - Misplaced Pages Continue
1792-535: The entire outcrop is not sandstone but Shackleton Limestone . 80°31′S 159°35′E / 80.517°S 159.583°E / -80.517; 159.583 A saddle rising to approximately 500 metres (1,600 ft), between the Miscast Nunataks and Mount Madison at west and east, and Byrd Glacier and Couzens Bay at north and south. It was named at the suggestion of the US Advisory Committee on Antarctic Names , in association with Couzens Bay, which
1848-473: The evolution of flightlessness hypothesized intraspecific competition selected for a reduced individual energy expenditure, which is achieved by the loss of flight. Some flightless varieties of island birds are closely related to flying varieties, implying flight is a significant biological cost . Flight is the most costly type of locomotion exemplified in the natural world. The energy expenditure required for flight increases proportionally with body size, which
1904-402: The fusion of wing elements, a cerebellar structure, the presence of a pygostyle for tail feathers, and an alula on the wing. These morphological traits suggest some affinities to volant groups. Palaeognathes were one of the first colonizers of novel niches and were free to increase in abundance until the population was limited by food and territory. A study looking at energy conservation and
1960-687: The head of Byrd Glacier. The feature includes Mount Fries and forms the southwestern boundary of Zeller Glacier . Named in honor of Colin Keating, who was the Secretary for Justice from 1997–2000. He had a distinguished 30 year career in the Public Service, mostly with the Ministry of Foreign Affairs and Trade, during which time he had a significant Antarctic focus through his work in the Legal Division and then as
2016-504: The later arrivals to remain smaller. In environments where flightless birds are not present, it is possible that after the K/T Boundary there were no niches for them to fill. They were pushed out by other herbivorous mammals . New Zealand had more species of flightless birds (including the kiwi , several species of penguins , the takahē , the weka , the moa, and several other extinct species ) than any other such location. One reason
2072-475: The loss of flight is an easier transition for birds than the loss and regain of flight, which has never been documented in avian history. Moreover, tinamou nesting within flightless ratites indicates ancestral ratites were volant and multiple losses of flight occurred independently throughout the lineage. This indicates that the distinctive flightless nature of ratites is the result of convergent evolution. Two key differences between flying and flightless birds are
2128-407: The main mass. The mountain is 4 nautical miles (7 km) east-northeast of Mount Tuatara on the south side of Byrd Glacier. So named by Advisory Committee on Antarctic Names (US-ACAN) because of the appearance of the mountain. 80°30′S 159°9′E / 80.500°S 159.150°E / -80.500; 159.150 . A group of four nunataks which rise to 910 metres (3,000 ft) on
2184-430: The ocean. Species with certain characteristics are more likely to evolve flightlessness. For example, species that already have shorter wings are more likely to lose flight ability. Some species will evolve flatter wings so that they move more efficiently underwater at the cost of their flight. Additionally, birds that undergo simultaneous wing molt, in which they replace all of the feathers in their wings at once during
2240-568: The plateau into Byrd Glacier. From southwest to northeast they are: 80°55′S 156°30′E / 80.917°S 156.500°E / -80.917; 156.500 . A glacier about 10 miles (16 km) long, flowing west-north-west to enter the south side of Byrd Glacier just north of Mount Fries. Named by US-ACAN for Edward J. Zeller, geologist at McMurdo Station, 1959–60 and 1960-61 seasons. 80°45′S 156°52′E / 80.750°S 156.867°E / -80.750; 156.867 . Glacier about 10 miles (16 km) long, flowing into
2296-638: The ratites, although they are not related. Divergences and losses of flight within ratite lineage occurred right after the K-Pg extinction event wiped out all non-avian dinosaurs and large vertebrates 66 million years ago. The immediate evacuation of niches following the mass extinction provided opportunities for Palaeognathes to distribute and occupy novel environments. New ecological influences selectively pressured different taxa to converge on flightless modes of existence by altering them morphologically and behaviorally. The successful acquisition and protection of
Kent Plateau - Misplaced Pages Continue
2352-513: The smaller wing bones of flightless birds and the absent (or greatly reduced) keel on their breastbone, which anchors muscles needed for wing movement. Adapting to a cursorial lifestyle causes two inverse morphological changes to occur in the skeleto-muscular system: the pectoral apparatus used to power flight is paedorphically reduced while peramorphosis leads to enlargement of the pelvic girdle for running. Repeated selection for cursorial traits across ratites suggests these adaptions comprise
2408-515: The south side of Byrd Glacier . The unit lies between Lowry Massif to the northeast and Mandarich Massif to the southwest. It was named in honor of Sir Peter Blake , who died in December 2001 during an environmental awareness expedition on the Amazon River . He was an exceptional sailor, and sought to raise worldwide awareness of environmental issues, to help protect life in, on and around the waters of
2464-608: The south side of Byrd Glacier just west of Rundle Peaks. Named by the US-ACAN for Ronald Sefton, ionospheric physicist, a member of the Byrd Station winter parties of 1962 and 1964. 80°35′S 157°45′E / 80.583°S 157.750°E / -80.583; 157.750 A glacier 6 miles (9.7 km) long, flowing from the north side of the Kent Plateau into the south side of Byrd Glacier. Named by US-ACAN for C.E. Twombley of
2520-410: The south side of Byrd Glacier, 7 miles (11 km) north of Mount Hamilton. Mapped by the NZGSAE (1960–61) who so named it because the long spiny summit ridge resembles a lizard. 80°31′S 158°41′E / 80.517°S 158.683°E / -80.517; 158.683 . A rounded and mostly ice-free mountain, about 1,000 metres (3,300 ft) high, with a narrow ridge running southwest from
2576-487: The south side of Byrd Glacier, surmounting the broad ridge between Zeller and Sefton Glaciers. So named by the NZGSAE (1960–61) as the peak consists of multi-colored beds of sandstone with probable dolerite sitting on pink-green limestone. 80°44′S 157°12′E / 80.733°S 157.200°E / -80.733; 157.200 . A cluster of mainly ice-covered peaks at the south side of Byrd Glacier, just east of Sefton Glacier. Named by US-ACAN for Arthur S. Rundle,
2632-470: The south side of Byrd Glacier. The outcrops lie between Mount Tadpole and Mount Madison . To their East is Couzens Saddle. The feature was geologically mapped as Dick Formation, a clastic, sandstone unit, by the New Zealand Geological Survey in 1960–61. The current name arose following remapping by United States Antarctic Program geologist Edmund Stump in 2000–01, and the determination that
2688-617: The summit commands a view of the drainage areas of Judith Glacier , Entrikin Glacier , and Couzens Bay . It was named by Advisory Committee on Antarctic Names (US-ACAN) after John "J.R." Roberts, a New Zealand mountaineer and field guide in 12 Antarctic seasons with United States Antarctic Program (USAP), 1987–88 to 2000–01, the last season in Churchill Mountains including work at this peak. 80°38′S 159°23′E / 80.633°S 159.383°E / -80.633; 159.383 . A rock summit rising to 1,200 metres (3,900 ft). It
2744-468: The vicinity of Mount Hamilton northeastward to enter Byrd Glacier just east of Mount Tuatara. Named by US-ACAN for Cdr. J.H. Judith, USN, commanding officer of the Edisto during USN OpDFrz 1964. Nearby features to the east include, from south to north: 80°49′S 157°21′E / 80.817°S 157.350°E / -80.817; 157.350 . A mountain rising to over 1,800 metres (5,900 ft) at
2800-650: The world. He sailed to the Antarctic Peninsula aboard the Seamaster in January 2001. 80°37′S 158°12′E / 80.617°S 158.200°E / -80.617; 158.200 . A compact block of ridgelines without a prominent culminating summit, rising to about 1,800 metres (6,000 ft) on the south side of Byrd Glacier. The unit is 3 nautical miles (6 km) long and stands 3 nautical miles south-southwest of Mount Tuatara. A section of Shackleton Limestone
2856-562: The year, are more likely to evolve flight loss. A number of bird species appear to be in the process of losing their powers of flight to various extents. These include the Zapata rail of Cuba , the Okinawa rail of Japan , and the Laysan duck of Hawaii . All of these birds show adaptations common to flightlessness, and evolved recently from fully flighted ancestors, but have not yet completely given up
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#17328587322862912-713: Was established in 1943 as the Special Committee on Antarctic Names (SCAN). It became the Advisory Committee on Antarctic Names in 1947. Fred G. Alberts was Secretary of the Committee from 1949 to 1980. By 1959, a structured nomenclature was reached, allowing for further exploration, structured mapping of the region and a unique naming system. A 1990 ACAN gazeeter of Antarctica listed 16,000 names. The United States does not recognise territorial boundaries within Antarctica, so ACAN assigns names to features anywhere within
2968-453: Was measured here by United States Antarctic Program geologist Edmund Stump on November 21, 2000. The massif is named after geologist Patrick H. Lowry, a member of Stump's Arizona State University field parties, 1977–78 and 1978–79, the latter season being in the Byrd Glacier area. 80°34′S 158°20′E / 80.567°S 158.333°E / -80.567; 158.333 . A mountain, 1,640 metres (5,380 ft) high, standing on
3024-573: Was named after an extinct and flightless bird species in New Zealand , the moa ( Dinornis gigantea ). The naming is in association with the adjacent feature, Kiwi Pass, which was named after a familiar nickname for New Zealanders , the kiwi being also a species of flightless bird (currently endangered and protected) found only in New Zealand. 80°40′S 158°17′E / 80.667°S 158.283°E / -80.667; 158.283 . A mountain, 1,990 metres (6,530 ft) high, standing at
3080-453: Was named by the Advisory Committee on Antarctic Names after Captain (later Rear Admiral) Stevan Mandarich (1911–2001), U.S. Navy , Chief of Staff to Rear Admiral Richard E. Byrd on Operation Deep Freeze I, 1955–56. 80°38′S 158°0′E / 80.633°S 158.000°E / -80.633; 158.000 . A compact block of ridgelines without a prominent culminating summit, rising to approximately 1,800 metres (5,900 ft) on
3136-575: Was named by the New Zealand Geological Survey Antarctic Expedition (1960–61) in honor of Lieutenant Thomas Couzens, Royal New Zealand Air Force , who lost his life in a crevasse accident near Cape Selborne on 19 November 1959. 80°36′S 158°45′E / 80.600°S 158.750°E / -80.600; 158.750 . A peak rising to 1,630 metres (5,350 ft), 5 nautical miles (9 km) southeast of Mount Tuatara. The culmination of several ridgelines,
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