bald_eagle
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| ===== I. BALD EAGLE MORPHOLOGY===== | ===== I. BALD EAGLE MORPHOLOGY===== | ||
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| - | Bald eagles are, on average, 80 or so centimetres in body length, and weigh up to 6 kilogrammes, | + | Bald eagles are, on average, 80 or so centimetres in body length, and weigh up to 6 kilogrammes, |
| The underside of the wings of the adult bald eagle, unlike other raptors, is not significantly different in colouration to the above side of the wings. When in flight, bald eagles have their wings fully out-stretched as they soar – so that the bord almost forms the letter ‘T' from below. When preparing to land, or to catch prey, the eagle contorts so that its legs are stretched in front of its bent head – so that from the front it resembles the shape of the letter ‘Y’. Like other eagles, the soaring ability of the bald eagle is efficient to such a degree that flapping is rare. | The underside of the wings of the adult bald eagle, unlike other raptors, is not significantly different in colouration to the above side of the wings. When in flight, bald eagles have their wings fully out-stretched as they soar – so that the bord almost forms the letter ‘T' from below. When preparing to land, or to catch prey, the eagle contorts so that its legs are stretched in front of its bent head – so that from the front it resembles the shape of the letter ‘Y’. Like other eagles, the soaring ability of the bald eagle is efficient to such a degree that flapping is rare. | ||
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| The breeding season of the bald eagle is dependent on the sub-species – the Northern Bald Eagles seem to breed predominantly from April to August – whereas the Southern Bald Eagles seem to breed predominantly from October to April. Bald Eagles seem to prefer their nests being placed in coniferous trees – though in some cases it also can be placed on the ground. When complete, the nest can be very large – about 2.5 metres in diameter, and about 4 metres deep. Both of the sexes contribute to construction of the large nest, though females predominantly do the placement of foundation of materials. Bald Eagles may return to the same nest for many years. On occasion, the nests can be even larger – the largest North American bird nest recorded to date was that of a bald eagle nest – found in Florida, the nest was almost 3 metres in diameter, and 6 metres deep. The nest is thought to have weighed more than 2000 kilogrammes. | The breeding season of the bald eagle is dependent on the sub-species – the Northern Bald Eagles seem to breed predominantly from April to August – whereas the Southern Bald Eagles seem to breed predominantly from October to April. Bald Eagles seem to prefer their nests being placed in coniferous trees – though in some cases it also can be placed on the ground. When complete, the nest can be very large – about 2.5 metres in diameter, and about 4 metres deep. Both of the sexes contribute to construction of the large nest, though females predominantly do the placement of foundation of materials. Bald Eagles may return to the same nest for many years. On occasion, the nests can be even larger – the largest North American bird nest recorded to date was that of a bald eagle nest – found in Florida, the nest was almost 3 metres in diameter, and 6 metres deep. The nest is thought to have weighed more than 2000 kilogrammes. | ||
| - | Bald eagles only breed once a year. Bald eagle eggs are incubated for about 25 days before hatching, and are speckled in colouration. Bald eagles seem to prioritise maximising egg number – in seasons of food abundance, as many as three eggs will be laid – but in other times, only two or just one will be laid. In a typical family structure, the male bald eagle provides food for the brooding female and their chicks. Though later in the chicks’ life, both parents bring food to the nest, with the female seemingly bringing more food. The female spends much time tending to the young in the first three or so weeks – though after this, the parents seem to leave the nest unattended for longer. After about 80 days or so, bald eagle chicks begin to fly. In increased maturity, bald eagle chicks also become increasingly violent – with killing of siblings common within the species. Typically, the first-hatched chick is the one who will kill any chicks which hatch afterward. They become sexually mature at 5 years of age typically – though in some populations only 8% or so reach breeding age. The oldest captive bald eagle on record was about 47 years old – and the oldest wild bald eagle on record was a New York bird which died at age 38. However, many wild birds die earlier than this, with a typical lifespan being one of about 20 years. | + | Bald eagles are rather social outside of the mating season, congregating at communal roosts. However, they are not co-operative in activities such as hunting or feeding – where rivalry often occurs between bald eagles and also other predators. In the mating season, however, they are very territorial – fending off rivals to their mates and offspring. The species is monogamous – it mates for life, except in the case either mate dies or does not return. |
| ===== III. BALD EAGLES IN HUMAN CULTURE===== | ===== III. BALD EAGLES IN HUMAN CULTURE===== | ||
| - | Before its adoption as the emblem of the United States, the bald eagle was a creature of high importance to the native peoples of North America. Eagles were common in arts of the Native Americans, and in the Native American | + | Before its adoption as the emblem of the United States, the bald eagle was a creature of high importance to the native peoples of North America. Eagles were common in arts of many, though not necessarily all, Native Americans, and in the many Native American |
| In the 18th century, about a century after the colonisation of North America by the Europeans, the bald eagle was printed onto a Massachusetts copper cent coin – the first coin printed to feature the animal. In 1783, three years before, the topic of the national emblem was discussed amongst people of high leadership. It wouldn’t be until six years later, in 1789, that the Bald Eagle would be adopted, as a symbol of courage and freedom. Not all proponents were supportive, however. Benjamin Franklin is known to have written - | In the 18th century, about a century after the colonisation of North America by the Europeans, the bald eagle was printed onto a Massachusetts copper cent coin – the first coin printed to feature the animal. In 1783, three years before, the topic of the national emblem was discussed amongst people of high leadership. It wouldn’t be until six years later, in 1789, that the Bald Eagle would be adopted, as a symbol of courage and freedom. Not all proponents were supportive, however. Benjamin Franklin is known to have written - | ||
| ‘//I wish the bald eagle had not been chosen as the representative of our country; he is a bird of bad moral character; like those among men who live by sharping and robbing, he is generally poor, and often very lousy. The turkey is a much more respectable bird and withal a true, original native of America.// | ‘//I wish the bald eagle had not been chosen as the representative of our country; he is a bird of bad moral character; like those among men who live by sharping and robbing, he is generally poor, and often very lousy. The turkey is a much more respectable bird and withal a true, original native of America.// | ||
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| Franklin’s sentiments carried little weight, however – and the bald eagle was quickly adopted as the emblem of the then 13 colonies that made up the United States. In the present day, the bald eagle appears on the Seal of the United States as well as the country’s Coat of Arms, as it has for over 200 years. President John F. Kennedy also thought highly of the Bald Eagle, and is known to have written to the Audubon Society – | Franklin’s sentiments carried little weight, however – and the bald eagle was quickly adopted as the emblem of the then 13 colonies that made up the United States. In the present day, the bald eagle appears on the Seal of the United States as well as the country’s Coat of Arms, as it has for over 200 years. President John F. Kennedy also thought highly of the Bald Eagle, and is known to have written to the Audubon Society – | ||
| ‘//The Founding Fathers made an appropriate choice when they selected the bald eagle as the emblem of the nation. The fierce beauty and proud independence of this great bird aptly symbolizes the strength and freedom of America. But as latter-day citizens we shall fail our trust if we permit the eagle to disappear.// | ‘//The Founding Fathers made an appropriate choice when they selected the bald eagle as the emblem of the nation. The fierce beauty and proud independence of this great bird aptly symbolizes the strength and freedom of America. But as latter-day citizens we shall fail our trust if we permit the eagle to disappear.// | ||
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| The Bald Eagle has since a potent symbol of the United States of America, symbolising to its citizens patriotism, strength, and liberty. | The Bald Eagle has since a potent symbol of the United States of America, symbolising to its citizens patriotism, strength, and liberty. | ||
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| Bald eagles have been hunted on occasion by Native Americans, though it is not believed that Native Americans caused significant decline within the species. When European colonists started to farm, they perceived bald eagles as a threat to livestock, and European hunters felt that bald eagles competed with them for game animals or fish. In the year 1917, the state of Alaska introduced a bounty system for the bald eagle, which resulted in at least 120,000 eagles being killed – and probably many more left unrecorded. The Bounty was repealed in 1953, but an already-damaged population would soon experience further dramatic decline. The most dramatic decline of the bald eagle, however, came after the Second World War when pesticides were used on agricultural crops. The pesticides would go on to enter waterways and began to accumulate within fish, the main food-source of bald eagles. DDT, known also as // | Bald eagles have been hunted on occasion by Native Americans, though it is not believed that Native Americans caused significant decline within the species. When European colonists started to farm, they perceived bald eagles as a threat to livestock, and European hunters felt that bald eagles competed with them for game animals or fish. In the year 1917, the state of Alaska introduced a bounty system for the bald eagle, which resulted in at least 120,000 eagles being killed – and probably many more left unrecorded. The Bounty was repealed in 1953, but an already-damaged population would soon experience further dramatic decline. The most dramatic decline of the bald eagle, however, came after the Second World War when pesticides were used on agricultural crops. The pesticides would go on to enter waterways and began to accumulate within fish, the main food-source of bald eagles. DDT, known also as // | ||
| - | In 1967, the Southern Bald Eagle was listed federally as an Endangered Species. The Endangered Species Act of 1973 enlisted further protection to certain Bald Eagle populations, | + | In 1967, the Southern Bald Eagle was listed federally as an Endangered Species. The Endangered Species Act of 1973 enlisted further protection to certain Bald Eagle populations, |
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| + | The Wenden Animal Encyclopaedia would like to thank especially: | ||
| + | **The John F[itzgerald]. Kennedy Presidential Library.** | ||
bald_eagle.1688992211.txt.gz · Last modified: by zookeeper
