Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, not all of which are related. Most of the 60 species of eagle are from Africa. Outside this area, just 14 species can be found—2 in North America, 9 in Central and South America, 3 in Australia. Eagles are large, powerfully built birds of prey, with heavy beaks; the smallest eagles, such as the booted eagle, comparable in size to a common buzzard or red-tailed hawk, have longer and more evenly broad wings, more direct, faster flight – despite the reduced size of aerodynamic feathers. Most eagles are larger than any other raptors apart from some vultures; the smallest species of eagle is the South Nicobar serpent eagle, at 40 cm. The largest species are discussed below. Like all birds of prey, eagles have large, hooked beaks for ripping flesh from their prey, muscular legs, powerful talons; the beak is heavier than that of most other birds of prey. Eagles' eyes are powerful.
It is estimated that the martial eagle, whose eye is more than twice as long as a human eye, has a visual acuity 3.0 to 3.6 times that of humans. This acuity enables eagles to spot potential prey from a long distance; this keen eyesight is attributed to their large pupils which ensure minimal diffraction of the incoming light. The female of all known species of eagles is larger than the male. Eagles build their nests, called eyries, in tall trees or on high cliffs. Many species lay two eggs, but the older, larger chick kills its younger sibling once it has hatched; the dominant chick tends to be a female. The parents take no action to stop the killing. Due to the size and power of many eagle species, they are ranked at the top of the food chain as apex predators in the avian world; the type of prey varies by genus. The Haliaeetus and Ichthyophaga eagles prefer to capture fish, though the species in the former capture various animals other water birds, are powerful kleptoparasites of other birds.
The snake and serpent eagles of the genera Circaetus and Spilornis predominantly prey on the great diversity of snakes found in the tropics of Africa and Asia. The eagles of the genus Aquila are the top birds of prey in open habitats, taking any medium-sized vertebrate they can catch. Where Aquila eagles are absent, other eagles, such as the buteonine black-chested buzzard-eagle of South America, may assume the position of top raptorial predator in open areas. Many other eagles, including the species-rich genus Spizaetus, live predominantly in woodlands and forest; these eagles target various arboreal or ground-dwelling mammals and birds, which are unsuspectingly ambushed in such dense, knotty environments. Hunting techniques differ among the species and genera, with some individual eagles having engaged in quite varied techniques based their environment and prey at any given time. Most eagles grab prey without landing and take flight with it, so the prey can be carried to a perch and torn apart.
The bald eagle is noted for having flown with the heaviest load verified to be carried by any flying bird, since one eagle flew with a 6.8 kg mule deer fawn. However, a few eagles may target prey heavier than themselves. Golden and crowned eagles have killed ungulates weighing up to 30 kg and a martial eagle killed a 37 kg duiker, 7–8 times heavier than the preying eagle. Authors on birds David Allen Sibley, Pete Dunne, Clay Sutton described the behavioral difference between hunting eagles and other birds of prey thus: They have at least one singular characteristic, it has been observed. All hawks seem to have this habit, from the smallest kestrel to the largest Ferruginous – but not the Eagles. Among the eagles are some of the largest birds of prey: only the condors and some of the Old World vultures are markedly larger, it is debated which should be considered the largest species of eagle. They could be measured variously in body mass, or wingspan. Different lifestyle needs among various eagles result in variable measurements from species to species.
For example, many forest-dwelling eagles, including the large harpy eagle, have short wingspans, a feature necessary for being able to maneuver in quick, short bursts through densely forested habitats. Eagles in the genus Aquila, though found strictly in open country, are superlative soarers, have long wings for their size; these lists of the top five eagles are based on weight and wingspan, respectively. Unless otherwise noted by reference, the figures listed are the median reported for each measurement in the guide Raptors of the World in which only measurements that could be verified by the authors were listed. Australasian Australia: wedge-tailed eagle, white-bellied sea-eagle, little eagle. New Guinea: Papuan eagle, white-bellied sea-eagle, pygmy eagle. Nearctic: golden eagle, bald eagle. Neotropical: Spizaetus, solitary eagles, harpy eagle, crested eagle, black-chested buzzard-eagle
The Accipitridae, one of the four families within the order Accipitriformes, are a family of small to large birds with hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-sized mammals, with a number feeding on carrion and a few feeding on fruit; the Accipitridae have a cosmopolitan distribution, being found on all the world's continents and a number of oceanic island groups. Some species are migratory. Many well-known birds, such as hawks, kites and Old World vultures are included in this group; the osprey is placed in a separate family, as is the secretary bird, the New World vultures are usually now regarded as a separate family or order. Karyotype data indicate the accipitrids analysed are indeed a distinct monophyletic group, but whether this group should be considered a family or one or several order on their own is a question still to be resolved; the accipitrids have been variously divided into some five to 10 subfamilies. Most share a similar morphology, but many of these groups contain taxa that are more aberrant.
These are placed in their respective position more for lack of better evidence than anything else. It is thus not surprising that the phylogenetic layout of the accipitrids has always been a matter of dispute; the accipitrids are recognizable by a peculiar rearrangement of their chromosomes. Apart from this, morphology and mtDNA cytochrome b sequence data give a confusing picture of these birds' interrelationships. What can be said is that the hawks, kites and Old World vultures as presently assigned in all likelihood do not form monophyletic groups: According to the molecular data, the Buteoninae are most poly- or paraphyletic, with the true eagles, the sea eagles, the buteonine hawks representing distinct lineages; these appear to form a group with the Milvinae and Circinae but the exact relationships between the lineages are not at all robustly resolvable with the present data. The Perninae and the Elaninae are older lineages, as are the Old World vultures; the latter are likely poly- or paraphyletic, with some aberrant species like the bearded and Egyptian vultures standing apart from the naked-necked "true" vultures.
The Accipitridae are a diverse family with a great deal of variation in shape. They range in size from the tiny pearl kite and little sparrowhawk, both of which are 23 cm in length and weigh about 85 g, to the cinereous vulture, which measures up to 120 cm and weighs up to 14 kg. Wingspan can vary from 39 cm in the little sparrowhawk to more than 300 cm in the cinereous and Himalayan vultures. In these extreme species, wing chord length can range from 113 to 890 mm and culmen length from 11 to 88 mm; until the 14th century these huge vultures were surpassed by the extinct Haast's eagle of New Zealand, estimated to have measured up to 140 cm and to have weighed 15 to 16.5 kg in the largest females. In terms of body mass, the Accipitridae are the most diverse family of birds and may be in terms of some aspects of linear size diversity, although lag behind the true parrots and pheasant family in length diversity. Most accipitrids exhibit sexual dimorphism in size, unusually for birds, it is the females that are larger than the males.
This sexual difference in size is most pronounced in active species that hunt birds, such as the Accipiter hawks, in which the size difference averages 25–50%. In a majority of species, such as generalist hunters and rodent-, reptile-, fish-, insect-hunting specialists, the dimorphism is less between a 5% to 30% size difference. In the carrion-eating Old World vultures and snail eating kites, the difference is non-existent; the beaks of accipitrids are hooked. In some species, there is a notch or'tooth' in the upper mandible. In all accipitrids, the base of the upper mandible is covered by a fleshy membrane called the cere, yellow in colour; the tarsi of different species vary by diet. The plumage of the Accipitridae can be striking, but utilises bright colours. Overall they tend to be paler below. There is sexual dimorphism in plumage, when it occurs the males are brighter or the females resemble juveniles. In many species juveniles have a distinctly different plumage; some accipitrids mimic the plumage patterns of other eagles.
They may attempt to resemble a less dangerous species to fool prey, or instead resemble a more dangerous species in order to reduce mobbing by other birds. Several species of accipitrid have crests used in signalling, species without crests can raise the feathers of the crown when alarmed or excited. In contrast most of the Old World vultures possess bare heads without feathers; the senses of the Accipitridae are adapted to hunting, in particular their vision is legendary. The sight of some hawks and eagles is up to 8 times better than that of humans. Large eyes with two fovea provide binocular vis
The harpy eagle is a neotropical species of eagle. It is called the American harpy eagle to distinguish it from the Papuan eagle, sometimes known as the New Guinea harpy eagle or Papuan harpy eagle, it is the largest and most powerful raptor found in the rainforest, among the largest extant species of eagles in the world. It inhabits tropical lowland rainforests in the upper canopy layer. Destruction of its natural habitat has caused it to vanish from many parts of its former range, it is nearly extirpated in Central America. In Brazil, the harpy eagle is known as royal-hawk; the harpy eagle was first described by Linnaeus in his Systema Naturae in 1758 as Vultur harpyja, after the mythological beast harpy. The only member of the genus Harpia, the harpy eagle is most related to the crested eagle and the New Guinea harpy eagle, the three composing the subfamily Harpiinae within the large family Accipitridae. Thought to be related, the Philippine eagle has been shown by DNA analysis to belong elsewhere in the raptor family, as it is related to the Circaetinae.
The species name harpyja and the word harpy in the common name harpy eagle both come from Ancient Greek harpyia. They refer to the Harpies of Ancient Greek mythology; these were wind spirits that took the dead to Hades, were said to have a body like an eagle and the face of a human. The upper side of the harpy eagle is covered with slate-black feathers, the underside is white, except for the feathered tarsi, which are striped black. A broad black band across the upper breast separates the gray head from the white belly; the head is pale grey, is crowned with a double crest. The upper side of the tail is black with three gray bands, while the underside of it is black with three white bands; the iris is gray or brown or red, the cere and bill are black or blackish and the tarsi and toes are yellow. The plumage of males and females are identical; the tarsus is up to 13 cm long. Female harpy eagles weigh 6 to 9 kg. One source states. An exceptionally large captive female, "Jezebel", weighed 12.3 kg. Being captive, this large female may not be representative of the weight possible in wild harpy eagles due to differences in the food availability.
The male, in comparison, weighs only about 4 to 4.8 kg. Harpy eagles have a wingspan of 176 to 224 cm. Among the standard measurements, the wing chord measures 54–63 cm, the tail measures 37–42 cm, the tarsus is 11.4–13 cm long, the exposed culmen from the cere is 4.2 to 6.5 cm. It is sometimes cited as the largest eagle alongside the Philippine eagle, somewhat longer on average, the Steller's sea eagle, heavier on average; the wingspan of the harpy eagle is small, an adaptation that increases maneuverability in forested habitats and is shared by other raptors in similar habitats. The wingspan of the harpy eagle is surpassed by several large eagles who live in more open habitats, such as those in the Haliaeetus and Aquila genera; the extinct Haast's eagle was larger than all extant eagles, including the harpy. This species is silent away from the nest. There, the adults give a penetrating, melancholy scream, with the incubating males' call described as "whispy screaming or wailing"; the females' calls while incubating are lower-pitched.
While approaching the nest with food, the male calls out "rapid chirps, goose-like calls, occasional sharp screams". Vocalization in both parents decreases as the nestlings age; the nestlings call chi-chi-chi...chi-chi-chi-chi in alarm in response to rain or direct sunlight. When humans approach the nest, the nestlings have been described as uttering croaks and whistles. Rare throughout its range, the harpy eagle is found from Mexico, through Central America and into South America to as far south as Argentina. In rainforests, they live in the emergent layer; the eagle is most common in Brazil. With the exception of some areas of Panama, the species is extinct in Central America, subsequent to the logging of much of the rainforest there; the harpy eagle inhabits tropical lowland rainforests and may occur within such areas from the canopy to the emergent vegetation. They occur below an elevation of 900 m, but have been recorded at elevations up to 2,000 m. Within the rainforest, they hunt in the canopy or sometimes on the ground, perch on emergent trees looking for prey.
They do not occur in disturbed areas, but visit semiopen forest/pasture mosaic in hunting forays. Harpies, can be found flying over forest borders in a variety of habitats, such as cerrados, buriti palm stands, cultivated fields, cities, they have been found in areas. Adults are near or at the top of a food chain and are preyed on. However, two adult eagles that were being released into the wild as part of a reintroduction program were taken by a jaguar and the much smaller ocelot Its main prey are tree-dwelling mammals and a majority of the diet has been shown to focus on sloths and monkeys. Research conducted by Aguiar-Silva between 2003 and 2005 in a nesting site in Parintins, Brazil, collected remains from prey offered to the nestling by its parents and after sor
The Precambrian is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic eon, named after Cambria, the Latinised name for Wales, where rocks from this age were first studied; the Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons of the geologic time scale, it spans from the formation of Earth about 4.6 billion years ago to the beginning of the Cambrian Period, about 541 million years ago, when hard-shelled creatures first appeared in abundance. Little is known about the Precambrian, despite it making up seven-eighths of the Earth's history, what is known has been discovered from the 1960s onwards; the Precambrian fossil record is poorer than that of the succeeding Phanerozoic, fossils from the Precambrian are of limited biostratigraphic use. This is because many Precambrian rocks have been metamorphosed, obscuring their origins, while others have been destroyed by erosion, or remain buried beneath Phanerozoic strata.
It is thought that the Earth coalesced from material in orbit around the Sun at 4,543 Ma, may have been struck by a large planetesimal shortly after it formed, splitting off material that formed the Moon. A stable crust was in place by 4,433 Ma, since zircon crystals from Western Australia have been dated at 4,404 ± 8 Ma; the term "Precambrian" is recognized by the International Commission on Stratigraphy as the only "supereon" in geologic time. "Precambrian" is still used by geologists and paleontologists for general discussions not requiring the more specific eon names. As of 2010, the United States Geological Survey considers the term informal, lacking a stratigraphic rank. A specific date for the origin of life has not been determined. Carbon found in 3.8 billion-year-old rocks from islands off western Greenland may be of organic origin. Well-preserved microscopic fossils of bacteria older than 3.46 billion years have been found in Western Australia. Probable fossils 100 million years older have been found in the same area.
However, there is evidence. There is a solid record of bacterial life throughout the remainder of the Precambrian. Excluding a few contested reports of much older forms from North America and India, the first complex multicellular life forms seem to have appeared at 1500 Ma, in the Mesoproterozoic era of the Proterozoic eon. Fossil evidence from the Ediacaran period of such complex life comes from the Lantian formation, at least 580 million years ago. A diverse collection of soft-bodied forms is found in a variety of locations worldwide and date to between 635 and 542 Ma; these are referred to as Vendian biota. Hard-shelled creatures appeared toward the end of that time span, marking the beginning of the Phanerozoic eon. By the middle of the following Cambrian period, a diverse fauna is recorded in the Burgess Shale, including some which may represent stem groups of modern taxa; the increase in diversity of lifeforms during the early Cambrian is called the Cambrian explosion of life. While land seems to have been devoid of plants and animals and other microbes formed prokaryotic mats that covered terrestrial areas.
Tracks from an animal with leg like appendages have been found in what was mud 551 million years ago. Evidence of the details of plate motions and other tectonic activity in the Precambrian has been poorly preserved, it is believed that small proto-continents existed prior to 4280 Ma, that most of the Earth's landmasses collected into a single supercontinent around 1130 Ma. The supercontinent, known as Rodinia, broke up around 750 Ma. A number of glacial periods have been identified going as far back as the Huronian epoch 2400–2100 Ma. One of the best studied is the Sturtian-Varangian glaciation, around 850–635 Ma, which may have brought glacial conditions all the way to the equator, resulting in a "Snowball Earth"; the atmosphere of the early Earth is not well understood. Most geologists believe it was composed of nitrogen, carbon dioxide, other inert gases, was lacking in free oxygen. There is, evidence that an oxygen-rich atmosphere existed since the early Archean. At present, it is still believed that molecular oxygen was not a significant fraction of Earth's atmosphere until after photosynthetic life forms evolved and began to produce it in large quantities as a byproduct of their metabolism.
This radical shift from a chemically inert to an oxidizing atmosphere caused an ecological crisis, sometimes called the oxygen catastrophe. At first, oxygen would have combined with other elements in Earth's crust iron, removing it from the atmosphere. After the supply of oxidizable surfaces ran out, oxygen would have begun to accumulate in the atmosphere, the modern high-oxygen atmosphere would have developed. Evidence for this lies in older rocks that contain massive banded iron formations that were laid down as iron oxides. A terminology has evolved covering the early years of the Earth's existence, as radiometric dating has allowed real dates to be assigned to specific formations and features; the Precambrian is divided into
The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago to the start of the Silurian Period 443.8 Mya. The Ordovician, named after the Celtic tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same rock beds in northern Wales into the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed strata were different from those of either the Cambrian or the Silurian systems, placed them in a system of their own; the Ordovician received international approval in 1960, when it was adopted as an official period of the Paleozoic Era by the International Geological Congress. Life continued to flourish during the Ordovician as it did in the earlier Cambrian period, although the end of the period was marked by the Ordovician–Silurian extinction events.
Invertebrates, namely molluscs and arthropods, dominated the oceans. The Great Ordovician Biodiversification Event increased the diversity of life. Fish, the world's first true vertebrates, continued to evolve, those with jaws may have first appeared late in the period. Life had yet to diversify on land. About 100 times as many meteorites struck the Earth per year during the Ordovician compared with today; the Ordovician Period began with a major extinction called the Cambrian–Ordovician extinction event, about 485.4 Mya. It lasted for about 42 million years and ended with the Ordovician–Silurian extinction events, about 443.8 Mya which wiped out 60% of marine genera. The dates given are recent radiometric dates and vary from those found in other sources; this second period of the Paleozoic era created abundant fossils that became major petroleum and gas reservoirs. The boundary chosen for the beginning of both the Ordovician Period and the Tremadocian stage is significant, it correlates well with the occurrence of widespread graptolite and trilobite species.
The base of the Tremadocian allows scientists to relate these species not only to each other, but to species that occur with them in other areas. This makes it easier to place many more species in time relative to the beginning of the Ordovician Period. A number of regional terms have been used to subdivide the Ordovician Period. In 2008, the ICS erected a formal international system of subdivisions. There exist Baltoscandic, Siberian, North American, Chinese Mediterranean and North-Gondwanan regional stratigraphic schemes; the Ordovician Period in Britain was traditionally broken into Early and Late epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column; the faunal stages from youngest to oldest are: Late Ordovician Hirnantian/Gamach Rawtheyan/Richmond Cautleyan/Richmond Pusgillian/Maysville/Richmond Middle Ordovician Trenton Onnian/Maysville/Eden Actonian/Eden Marshbrookian/Sherman Longvillian/Sherman Soudleyan/Kirkfield Harnagian/Rockland Costonian/Black River Chazy Llandeilo Whiterock Llanvirn Early Ordovician Cassinian Arenig/Jefferson/Castleman Tremadoc/Deming/Gaconadian The Tremadoc corresponds to the Tremadocian.
The Floian corresponds to the lower Arenig. The Llanvirn occupies the rest of the Darriwilian, terminates with it at the base of the Late Ordovician; the Sandbian represents the first half of the Caradoc. During the Ordovician, the southern continents were collected into Gondwana. Gondwana started the period in equatorial latitudes and, as the period progressed, drifted toward the South Pole. Early in the Ordovician, the continents of Laurentia and Baltica were still independent continents, but Baltica began to move towards Laurentia in the period, causing the Iapetus Ocean between them to shrink; the small continent Avalonia separated from Gondwana and began to move north towards Baltica and Laurentia, opening the Rheic Ocean between Gondwana and Avalonia. The Taconic orogeny, a major mountain-building episode, was well under way in Cambrian times. In the early and middle Ordovician, temperatures were mild, but at the beginning of the Late Ordovician, from 460 to 450 Ma, volcanoes along the margin of the Iapetus Ocean spewed massive amounts of carbon dioxide, a greenhouse gas, into the atmosphere, turning the planet into a hothouse.
Sea levels were high, but as Gondwana moved south, ice accumulated into glaciers and sea levels dropped. At first, low-lying sea beds increased diversity, but glaciation led to mass extinctions as the seas drained and continental shelves became dry land. During the Ordovician, in fact during the Tremadocian, marine transgressions worldwide were the greatest for which evidence is preserved; these volcanic island arcs collided with proto North America to form the Appalachian mountains. By the end of the Late Ordovician the volcanic emissions had stopped. Gondwana had by that time neared the South Pole and was glaciated
The martial eagle is a large eagle native to sub-Saharan Africa. It is the only member of the genus Polemaetus. A species of the booted eagle subfamily, it has feathering over its tarsus. One of the largest and most powerful species of booted eagle, it is a opportunistic predator that varies it prey selection between mammals and reptiles, its hunting technique is unique as it is one of few eagle species known to hunt from a high soar, by stooping on its quarry. An inhabitant of wooded belts of otherwise open savanna, this species has shown a precipitous decline in the last few centuries due to a variety of factors; the martial eagle is one of the most persecuted bird species in the world. Due to its habit of taking livestock and regionally valuable game, local farmers and game wardens seek to eliminate martial eagles, although the effect of eagles on this prey is certainly exaggerated; the martial eagle is classified with the status of Vulnerable to extinction by the IUCN. The martial eagle can be found in most of sub-Saharan Africa, wherever food is abundant and the environment favourable.
With a total estimated distribution of about 26,000 km2, it is widely distributed in the continent, having a somewhat broader range than species like the crowned eagle and the Verreaux's eagle. Although never common, greater population densities do exist in southern Africa and in some parts of east Africa. Martial eagles tend to be rare and irregular in west Africa but are known to reside in Senegal, The Gambia and northern Guinea-Bissau, southern Mali and the northern portions of Ivory Coast and Ghana. From southern Niger and eastern Nigeria the species is distributed spottily through Chad and the Central African Republic as well as the northern and southern portions of the Democratic Republic of the Congo. In east Africa, they range from northwestern Somalia and Ethiopia more or less continuously south through Kenya, Tanzania and in southern Africa from Angola, Zambia and southern Mozambique to South Africa; some of the larger remaining populations are known to persist in South Africa. These birds are more abundant in protected areas such as Kruger National Park and Kgalagadi Transfrontier Park in South Africa, or Etosha National Park in Namibia.
The Accipitridae family is by far the most diverse family of diurnal raptors in the world with more than 230 accepted species. As a member of the booted eagle subfamily, Aquilinae, it is one of the 15% extant species of the family to have feathers covering its legs; this may be a useful feature for distinguishing these species from other eagles and raptors, as they are present in tropical species such as the martial eagle. Under current classifications, booted eagles consist of 38 living species that are distributed in every continent inhabited by the accipitrids, which excludes only the continent of Antarctica. Just under half of the living species of booted eagle are found in Africa. Studies have been conducted on the mitochondrial DNA of most booted eagle species, including the martial eagle, in order to gain insight on how the subfamily is ordered and which species bear relation to one another. DNA testing in the 1980s indicated the martial eagle was a specialized off-shoot of the small-bodied Hieraaetus eagles and one study went so far as to advocate that the martial eagle be included in the genus.
However, more modern and comprehensive genetic testing has shown that the martial eagle is distinct from other living booted eagles and diverged from other existing genera several million years ago. Genetically, the martial eagle fell between two other species in monotypical genera, the African long-crested eagle and the Asian rufous-bellied eagle, that diverged long ago from other modern species. Given the disparity of this species’ unique morphology and that the two aforementioned most related living species are only about as large as the bigger buzzards, the unique heritage of the martial eagle is considered superficially evident. There are no subspecies of martial eagle and the species varies little in appearance and genetic diversity across its distribution; the martial eagle is a large eagle. In total length, it can range from 78 to 96 cm, with an average of 85.5 cm. Its total length – in comparison to its wingspan – is restricted by its short tail. Nonetheless, it appears to be the seventh longest living eagle species.
The wingspan of martial eagles can range from 188 to 260 cm. Average wingspans have been claimed of 205 cm and 207.5 cm for the species, however ten measured martial eagles in the wild were found to average 211.9 cm in wingspan. Thus, the martial eagle appears to average fourth in wingspan among living eagles, behind only the Steller's sea-eagle, the white-tailed eagle and the wedge-tailed eagle, in that order. For a species, homogeneous in its genetic make-up, the body mass of martial eagles is variable. To some extent, the variation of body masses in the species is attributable to considerable reverse sexual dimorphism as well as varying environmental conditions of various eagle populations. Unsexed martial eagles from various studies have been found to have weighed an average of 3.93 kg in 17 birds, 3.97 kg in 20 birds and 4.23 kg in 20 birds while the average weight of martial eagles shot by game wardens in the early 20th
The Māori are the indigenous Polynesian people of New Zealand. Māori originated with settlers from eastern Polynesia, who arrived in New Zealand in several waves of canoe voyages some time between 1250 and 1300. Over several centuries in isolation, the Polynesian settlers developed a unique culture, with their own language, a rich mythology, distinctive crafts and performing arts. Early Māori formed tribal groups based on organisation. Horticulture flourished using plants; the arrival of Europeans to New Zealand, starting in the 17th century, brought enormous changes to the Māori way of life. Māori people adopted many aspects of Western society and culture. Initial relations between Māori and Europeans were amicable, with the signing of the Treaty of Waitangi in 1840, the two cultures coexisted as part of a new British colony. Rising tensions over disputed land sales led to conflict in the 1860s. Social upheaval, decades of conflict and epidemics of introduced disease took a devastating toll on the Māori population, which fell dramatically.
By the start of the 20th century, the Māori population had begun to recover, efforts have been made to increase their standing in wider New Zealand society and achieve social justice. Traditional Māori culture has thereby enjoyed a significant revival, further bolstered by a Māori protest movement that emerged in the 1960s. In the 2013 census, there were 600,000 people in New Zealand identifying as Māori, making up 15 percent of the national population, they are the second-largest ethnic group in New Zealand, after European New Zealanders. In addition, more than 140,000 Māori live in Australia; the Māori language is spoken to some extent by about a fifth of all Māori, representing 3 per cent of the total population. Māori are active in all spheres of New Zealand culture and society, with independent representation in areas such as media and sport. Disproportionate numbers of Māori face significant economic and social obstacles, have lower life expectancies and incomes compared with other New Zealand ethnic groups.
They suffer higher levels of crime, health problems, educational under-achievement. A number of socioeconomic initiatives have been instigated with the aim of "closing the gap" between Māori and other New Zealanders. Political and economic redress for historical grievances is ongoing. In the Māori language, the word māori means "normal", "natural" or "ordinary". In legends and oral traditions, the word distinguished ordinary mortal human beings—tāngata māori—from deities and spirits. Wai māori denotes "fresh water", as opposed to salt water. There are cognate words in most Polynesian languages, all deriving from Proto-Polynesian *maqoli, which has the reconstructed meaning "true, genuine"; the spelling of "Māori" with or without the macron is inconsistent in general-interest English-language media in New Zealand, although some newspapers and websites have adopted the standard Māori-language spelling. Early visitors from Europe to New Zealand referred to the indigenous inhabitants as "New Zealanders" or as "natives".
The Māori used the term Māori to describe themselves in a pan-tribal sense. Māori people use the term tangata whenua to identify in a way that expresses their relationship with a particular area of land; the term can refer to the Māori people as a whole in relation to New Zealand as a whole. The Māori Purposes Act of 1947 required the use of the term "Māori" rather than "Native" in official usage; the Department of Native Affairs was renamed as the Department of Māori Affairs. Before 1974, the government required documented ancestry to determine the legal definition of "a Māori person". For example, bloodlines or percentage of Māori ancestry was used to determine whether a person should enroll on the general electoral roll or the separate Māori roll. In 1947, the authorities determined that a man, five-eighths Māori had improperly voted in the general parliamentary electorate of Raglan; the Māori Affairs Amendment Act 1974 changed the definition, allowing individuals to self-identify as to their cultural identity.
In matters involving financial benefits provided by the government to people of Māori ethnicity—scholarships, for example, or Waitangi Tribunal settlements—authorities require some documentation of ancestry or continuing cultural connection but no minimum "blood" requirement exists as determined by the government. The most current reliable evidence indicates that the initial settlement of New Zealand occurred around 1280 CE, at the end of the medieval warm period. Previous dating of some kiore bones at 50–150 has now been shown to have been unreliable. Māori oral history describes the arrival of ancestors from Hawaiki, in large ocean-going waka. Migration accounts vary among tribes, whose members may identify with several waka in their genealogies. In the last few decades, mitochondrial-DNA research has allowed an estimate to be made of the number of women in the founding population—between 50 and 100. Evidence fro