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Pedra Branca, Tasmania
Pedra Branca is a rock islet in the Southern Ocean, off the southern coast of Tasmania, Australia. The island is situated approximately south southeast of South East Cape and is contained within the Southwest National Park, part of the Tasmanian Wilderness World Heritage Site. An erosional remnant of the Tasmanian mainland, the island is approximately long, wide, with an elevation of above sea level. The island is estimated to have separated from the Tasmanian mainland at least 15,000 years ago. Features and location Pedra Branca experiences wet and windy weather, and large waves. With an area of , the island is small enough to provide an example of an outcrop that lies on the border between being a rock or islet and an island. The geology features three breccia cones of dolerite and sandstone. Flora and fauna The only plant species found on the island is the succulent ''Sarcocornia quinqueflora''. Recorded breeding seabird species include fairy prion, Pacific gull, sil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolerite
Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained to aphanitic chilled margins which may contain tachylite (dark mafic glass). ''Diabase'' is the preferred name in North America, while ''dolerite'' is the preferred name in the rest of the English-speaking world, where sometimes the name ''diabase'' refers to altered dolerites and basalts. Some geologists prefer to avoid confusion by using the name ''microgabbro''. The name ''diabase'' comes from the French ', and ultimately from the Greek - meaning "act of crossing over, transition". Petrography Diabase normally has a fine but visible texture of euhedral lath-shaped plagioclase crystals (62%) set in a finer matrix of clinopyroxene, typically augite (20–29%), with minor olivine (3% up to 12% in olivine diabase), magnetite (2%), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hauling-out
Hauling-out is a behaviour associated with pinnipeds (true seals, sea lions, fur seals and walruses) temporarily leaving the water. Hauling-out typically occurs between periods of foraging activity. Rather than remain in the water, pinnipeds haul-out onto land or sea-ice for reasons such as reproduction and rest. Hauling-out is necessary in seals for mating (with the exception of the Baikal seal) and giving birth (although a distinction is generally made between reproductive aggregations, termed "rookeries", and non-reproductive aggregations, termed "haul-outs"). Other benefits of hauling-out may include predator avoidance, thermoregulation, social activity, parasite reduction and rest. There is much variation in haul-out patterns among different seal species.Hoelzel, A. Rus. (2002). ''Marine Mammal Biology: An Evolutionary Approach''. Blackwell Publishing. . p. 197. Haul-out sites may be segregated by age and sex within the same species. Many species of pinniped have only a fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian Fur Seal
The brown fur seal (''Arctocephalus pusillus''), also known as the Cape fur seal, South African fur seal and Australian fur seal, is a species of fur seal. Description The brown fur seal is the largest and most robust member of the fur seals. It has a large and broad head with a pointed snout that may be flat or turned up slightly. They have external ear flaps (pinnae) and their whiskers (vibrissae) are long, and may extend backward past the pinnae, especially in adult males. The fore flippers are covered with sparse hair over about three-quarters of their length. The hind flippers are short relative to the large body, with short, fleshy tips on the digits. The size and weight of the brown fur seal depends on the subspecies. The Southern African subspecies is on average slightly larger than the Australian subspecies. Males of the African subspecies (''A. p. pusillus'') are in length on average and weigh . Females are smaller, averaging in length and typically weighing .King, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shy Albatross
The shy albatross, also known as shy mollymawk, (''Thalassarche cauta'', formerly ''Diomedea cauta''), is a medium-sized albatross that breeds on three remote islands off the coast of Tasmania, Australia, in the southern Indian Ocean. Its lifespan is about 60 years, and it has been seen as far afield as South Africa and the Pacific coast of the United States. , the species is listed as "Endangered" in Australia; there are thought to be 15,000 pairs of shy albatross left. It is Australia's only endemic albatross. Some authorities call this species the white-capped albatross, but the White-capped albatross is generally the common name given to ''Thalassarche cauta steadi''. Taxonomy This mollymawk was once considered to be the same species as the Salvin's albatross, ''Thalassarche salvini'' and the Chatham albatross, ''Thalassarche eremita'', but they were split around 2004. In 1998, Robertson and Nunn suggested a four-way split including the white-capped albatross, ''Thalass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australasian Gannet
The Australasian gannet (''Morus serrator''), also known as the Australian gannet or tākapu, is a large seabird of the booby and gannet family, Sulidae. Adults are mostly white, with black flight feathers at the wingtips and lining the trailing edge of the wing. The central tail feathers are also black. The head is tinged buff-yellow, with a pale blue-grey bill edged in black, and blue-rimmed eyes. Young birds have mottled plumage in their first year, dark above and light below. The head is an intermediate mottled grey, with a dark bill. The birds gradually acquire more white in subsequent seasons until they reach maturity after five years. The species range over water above the continental shelf along the southern and eastern Australian coastline, from Steep Point in Western Australia to Rockhampton, Queensland, as well as the North and South Islands of New Zealand, Lord Howe and Norfolk Islands. Nesting takes place in colonies along the coastlines of New Zealand, Victoria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black-faced Cormorant
The black-faced cormorant (''Phalacrocorax fuscescens''), also known as the black-faced shag, is a medium-sized member of the cormorant family. Upperparts, including facial skin and bill, are black, with white underparts. It is endemic to coastal regions of southern Australia. Description Like other cormorant species, the black-faced cormorant is a large aquatic bird, with a long hooked bill, webbed feet, and monochromatic plumage. This is one of the largest cormorants found in south-western Australia and has pied plumage with the upper half of its body black and the undersides white. Its face is naked and black, hence the "black-faced" name, and the tail, feet, and thighs are also black. The back feathers are glossy, and its bill is dark grey with a prominent hook at the tip. It has blue-green eyes. When flying, it holds its head level or lower than its body and holds its wings in a cross-shape like most cormorants. Species that are similar in appearance include the pied c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelp Gull
The kelp gull (''Larus dominicanus''), also known as the Dominican gull, is a gull that breeds on coasts and islands through much of the Southern Hemisphere. The nominate ''L. d. dominicanus'' is the subspecies found around South America, parts of Australia (where it overlaps with the Pacific gull), and New Zealand (where it is known as the black-backed gull, the southern black-backed gull, mollyhawk – particularly the juveniles, or by its Māori name ''karoro''). ''L. d. vetula'' (known as the Cape gull) is a subspecies occurring around Southern Africa. The specific name comes from the Dominican Order of friars, who wear black and white habits. Description The kelp gull superficially resembles two gulls from further north in the Atlantic Ocean, the lesser black-backed gull and the great black-backed gull and is intermediate in size between these two species. This species ranges from in total length, from in wingspan and from in weight. Adult males and females weigh on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver Gull
The silver gull (''Chroicocephalus novaehollandiae'') is the most common gull of Australia. It has been found throughout the continent, but particularly at or near coastal areas. It is smaller than the Pacific gull (''Larus pacificus''), which also lives in Australia. The silver gull should not be confused with the herring gull, which is called "silver gull" in many other languages (scientific name ''Larus argentatus'', German ''Silbermöwe'', French ''Goéland argenté'', Dutch ''zilvermeeuw''), but is a much larger, robust gull with no overlap in range. Taxonomy It has traditionally been placed in the genus ''Larus'', as is the case with many gulls, but is now placed in the genus ''Chroicocephalus''. Hartlaub's gull (''C. hartlaubii'') of South Africa was formerly sometimes considered to be subspecies of the silver gull. There are three subspecies: * ''C. n. forsteri'' ( Mathews, 1912) – north and northeast Australia, New Caledonia, Loyalty Islands * ''C. n. novaehollan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Gull
The Pacific gull (''Larus pacificus'') is a very large gull, native to the coasts of Australia. It is moderately common between Carnarvon in the west, and Sydney in the east, although it has become scarce in some parts of the south-east, as a result of competition from the kelp gull, which has "self-introduced" since the 1940s. Much larger than the ubiquitous silver gull, and nowhere near as common, Pacific gulls are usually seen alone or in pairs, loafing around the shoreline, steadily patrolling high above the edge of the water, or (sometimes) zooming high on the breeze to drop a shellfish or sea urchin onto rocks. Diet The gulls' diet consists of a number various fish species and invertebrates. They frequently consume crabs, most often the species ''Ovalipes australiensis'' and ''Paragrapsus gaimardii.'' They also commonly eat '' Platycephalus bassensis'' (sand flatheads) and cephalapods, both of which are sourced from their regular consumption of waste from fish which hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fairy Prion
The fairy prion (''Pachyptila turtur'') is a small seabird with the standard prion plumage of blue-grey upperparts with a prominent dark "M" marking and white underneath. The sexes are alike. This is a small prion of the low subantarctic and subtropic seas. Taxonomy The fairy prion was formally described in 1820 by the German naturalist Heinrich Kuhl under the binomial name ''Procellaria turtur''. It is now placed with the other prions in the genus ''Pachyptila'' that was introduced in 1811 by Johann Karl Wilhelm Illiger. The genus name combines the Ancient Greek ''pakhus '' meaning "dense" or "thick" with ''ptilon'' meaning "feather" or "plumage". The specific epithet ''turtur'' is Latin for "turtle dove". The word comes from the Ancient Greek word meaning "a saw", which is in reference to its serrated edges of its bill.Gotch, A. T. (1995) The fairy prion is a member of the genus ''Pachyptila'', and along with the blue petrel makes up the prions. They in turn are members of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seabird
Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period, and modern seabird families emerged in the Paleogene. In general, seabirds live longer, breed later and have fewer young than other birds do, but they invest a great deal of time in their young. Most species nest in colonies, which can vary in size from a few dozen birds to millions. Many species are famous for undertaking long annual migrations, crossing the equator or circumnavigating the Earth in some cases. They feed both at the ocean's surface and below it, and even feed on each other. Seabirds can be highly pelagic, coastal, or in some cases spend a part of the year away from the sea entirely. Seabirds and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_in_flight%2C_from_above.jpg "Click for more on -> Australasian Gannet")
