The black swan is one of the largest water birds. It has a long “S” shaped neck, with a red bill. It can weigh up to 20 pounds, with a wingspan near 6 feet and a length around 4 feet. The black swan is the official bird of Western Australia. It’s the symbol of the Aboriginal people and the white swan symbolizes Australians, with a European background. Of all the species of swans, only two are not pure white, one in Australia and one in South America.

Black swans are common in the southern parts of Australia and in the southeast of Tasmania and now, some can also be spotted in New Zealand and Europe. Black swans like to live near rivers, lakes and swampland; and the water can be fresh or salt. Black swans like to eat underwater vegetation, but they can also be seen in dry pastures and flooded fields, when food is in short supply.

Black swans mate for life. They usually separate in pairs, during mating, but there are times when they’ll mate in colonies. The breeding period is from February through September. The female usually handles the nest building and the nest could be inland, or floating on top of water. The female may lay between 4 to 7 eggs and the eggs are laid one day apart. After all the eggs have been laid, there’s normally a 35 to 48 day incubation period. The male may help with the incubation, but usually he’s protecting the nest from intruders. The baby swans are called cygnets. It takes little time before the cygnets learn to swim and feed themselves.

Although cygnets can fly within 2 months, they normally stay with their parents until the next breeding season. The cygnets will be sexually mature within 18 to 36 months. The young swans join juvenile flocks until they find a mate. Pairs are normally created one or two years before breeding begins. Maybe it’s because of their diet, but black swans have been known to live up to 40 years in the wild.

The black swans normally move in flocks and like ducks, they shed all their flight feathers at once. This is a very dangerous period for the swans, because they can’t fly and it leaves them susceptible to hunters, who may want their skins. The female sheds during the time she’s laying eggs and nesting. The male will start to shed as the female regains her ability to fly. The benefit in alternate shedding is that it guarantees that at least one parent will always be guarding the eggs.

Black swans have been called glorified geese, but geese have never been as popular as black swans. There’s something mesmerizing about watching black swans swim. They seem to command attention. Of course, anything people become fascinated with, they want to own, which is why there’s a market for black swan breeders. Having a pet is fun, especially if it’s exotic, but people should always be cautious when it comes to removing animals from their natural habitat. There’s more to owning a pet than the purchase.

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Pecan trees, ‘Carya illinoinensis,’ grow in natural groves in bottom lands near rivers or lakes with nearby periodic overflowing water. Archeological remains and fossil evidence reveals that pecans were collected and stored by Indians, the original settlers and inhabitants of America, and the group now known as the “mound builders.” American Indians followed this same example and were actively gathering pecan nuts when the European colonists arrived. The pecan trees were found growing in their northern limits along the tributaries of the Mississippi River near Louisville, Kentucky; Terra Haute, Indiana; and Clinton, Iowa, which is located at the same latitude as Chicago, Illinois.

Thomas Jefferson planted pecan trees, ‘Carya illinoinensis,’ (Illinois nuts) in his nut orchard at his beautiful home, Monticello, in Virginia; and George Washington reported in his journal that Thomas Jefferson gave him “Illinois nuts;” pecans which grew at Mount Vernon, Virginia, George Washington’s home. The trees grew and remain majestic in height and spread proudly even today. He called agriculture “the noblest of occupations.”

Pecan trees are native to the United States and are found growing naturally nowhere else in the world. The range of native pecan trees are found growing along rivers in Texas and in surrounding lands of the lower Mississippi River up to Louisville, Kentucky; Terra Haute, Indiana; and Clinton, Iowa, which is at the same latitude as Chicago, Illinois. Native pecan trees are also found growing as far west as Oklahoma, Missouri, and Kansas. Nomadic tribes of Indians carried these nuts from their native habitat into other areas of the United States and planted the nuts there as seed. Some of these trees have grown and survived as ‘Goliath’ specimens, such as one seedling with a 7 foot diameter trunk that is located at the TyTy, Georgia, nursery farm.

The shape of pecan nuts is highly variable; some are oval shaped and some are long and skinny. The size of the nuts can be as small as a pencil eraser or as large as 1.5″ inches in diameter to over three inches long. The kernels can vary in size within the hull; some filling out poorly or some not filling out at all. Some pecans have a kernel density so compact that the shells can be broken while the nuts are still on the tree by the swelling pressure that is generated from within, especially after heavy rains at the end of the ripening season.

The thinness of the shells of pecans is an important characteristic in determining the value of pecans. The term ‘papershell pecan’ refers to the thinness that allows two nuts placed in the fist to be easily cracked, usually producing ‘perfect halves.’ This thinness of the shell occurs occasionally in the extremea pecan cultivar with such thinness of the shell that the nut can easily be cracked between two fingers like a peanut. A disadvantage of this extreme thinness can occur when hurricanes come up from the Gulf causing long rainy periods. The kernels swell internally and the shells crack on the tree, providing an entry point for disease that can lead to damage or crop loss. Some years hurricanes have struck crops in September, before kernels of nuts have reached full maturity and immature nuts covered by green shucks were blown onto the ground, sometimes creating a layer several inches thick. These nuts are not worth saving, unless they fully mature on the pecan tree to the point beyond the shucks turning a deep brown or black color.

Pollination is not an important factor for pecan trees in most of the South and in areas where the pecan trees are native. The reason for this is that pecan trees are wind pollinated and pollen from a tree ten miles away can be pollinated if wind currents are favorable to transfer the pollen from one tree to the other. Some trees are self-pollinating, such as the ‘Desirable’ cultivar of pecan, because the pollen and the female flowers both mature near the same time. Other pecan cultivars have pollen that matures too soon or too late to be effective in pollination of the female flowers. There are enough pecan trees in most naturalized areas of the pecan zones to provide adequate cross-pollination; however, the ‘Desirable’ pecan is generally considered to be the best all-around pollinator, and most orchardists plant one of these pollinator trees at each end of the pecan orchard to ensure complete pollination. In Northern and far Western areas of the United States, it is suggested that a pecan tree buyer get the best information possible before deciding which cultivars to plant.

Despite the fact of the pecan tree’s Southern origin, the nut shows a surprisingly resilient resistance to cold. The pecan tree will live through low temperatures of zero degrees Fahrenheit and other drastic, sudden weather changes.

Pecan trees that produce superior nuts with characteristics of large size, papershell, high kernel quality, reliable production, and resistance to disease are grafted onto native (seedling) understock to ultimately produce uniform crops of harvested nuts in a cultivated orchard environment. Research has shown that the understock can have a considerable influence on the cultivar in terms of tree vigor. Most pecan tree nurseries plant the seed of “Moore” or “Curtis” cultivars to produce a predictable, balanced end-product, which has proven to be satisfactory. Early American nurserymen found that pecan scions could be grafted onto the rootstock of hickory and walnut trees, both of which are closely related to pecan trees, but these grafts were not satisfactory for orchardistsonly to hobbyists.

Diseases of pecans over the years have caused the withdrawal of many of the original cultivars from the market. First they seemed resistant to the notorious ’scab.’ This infection causes black spots to appear on the leaves that can spread to the hulls of the nuts, and later in the growing season can cause the premature blackening and drop of the nuts. Sometimes whole crops of nuts can be affected or lost during rainy summers and hurricane season unless the trees are sprayed often. Some insects can damage the quality of ripening nuts or even cause premature dropping; however, many orchardists now control all problems of pecan trees by periodic spraying and weed control. Zinc, manganese, magnesium, and boron deficient soils of the Southeast can be inexpensively controlled easily by soluble, small applications of the elements.

Land speculators of the 1920’s planted thousands of acres of pecan orchards in South Georgia, near Albany, with the idea of reaping huge profits from nut production. The trees were subjected to scab infections, that seemed to have mutated and preferentially attacked some cultivars and other cultivars showed different stages of immunity to the disease. New preventive sprays were not available at that time to protect the pecan trees, but many of those orchards have been revived to produce profitable harvests by spraying programs or by topworking the trees to scab resistant cultivars.

In Central Georgia, where peach production flourished for many years, many pecan trees were planted at large distances between the peach trees, because peach trees only have a life expectancy of 10-15 years. The peach growers hoped that when the peach orchards died out, they would be replaced by mature pecan trees, ‘in situ,’ which is exactly what happened. Central Georgia has become a major producer of high quality papershell pecans as a result of the insight of the peach tree growers and their correct selection of new, superior pecan tree cultivars.

Pecan nuts were reported to contain higher antioxidants than any other nuts, followed by walnuts and hazelnuts (filberts) in the June 9, 2004, issue of Journal of Agricultural and Food Chemistry. Antioxidants help to prevent, repair, and reduce oxidative stress a mechanism that interferes in healthy body functions by damaging cells that can lead to the formation of cancer, heart disease, Alzheimer’s Disease, and Parkinson’s Disease.

Dr. Jose Pena, extension economist in Uvalde, Texas, stated that “consumers prefer pecans over walnuts and almonds,” even though they are purchased at a higher price. The U.S. Department of Agriculture recommends that citizens should eat 3 to 5 servings of nuts each day to maintain a healthy diet. “Just a handful of pecans offers Vitamin E, calcium, magnesium, potassium, zinc, fiber, and more antioxidants than any other nut.”

Pecans have a very high concentration of Vitamin A that protects teeth, eyes, and bones, as well as benefiting general health. Because of recent interest in nuts as a healthy food, sales of pecans and other nuts have skyrocketed. Pecans offer a delicious, healthy nut to world markets with profitable financial rewards to those who choose to plant and market the product.

Copyright 2006 Patrick Malcolm

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One of the great mysteries and puzzles of our time is Atlantis. Despite the passage of thousands of years, no one has been able to solve the enigma of Atlantis.

Plato was the person that started all of the trouble regarding Atlantis. In his Timaeus and Critias narratives, he talked of Atlantis in glowing terms. He identified it as a large island located in the Atlantic Ocean. By large, we mean huge. Plato claimed it was the size of North Africa! The people of Atlantis supposedly controlled much of the Mediterranean, but were defeated by the ancestors of the Greeks. Both societies were then destroyed in “a great deluge.”

With just these snippets of information, one might assume Plato was taking some liberties in his writing. Then an odd thing occurred. Archeologists discovered Egyptian records detailing Atlantis, its ruling family and a utopian type culture. There are a lot of timing inconsistencies between the two stories, but the race to discover Atlantis has been on ever since. We do, after all, like a good puzzle.

So, where is Atlantis? Therein is the problem. The descriptions are so vague that Atlantis could be just about anywhere. Heck, you might be sitting above the main city as you read this. At one time or another, popular theory has suggested Atlantis is Antarctica, Turkey, North America, South America, Santorini, Crete, Indonesia and a pure figment of someone’s imagination. After years of searching, the imagination theory seems the most credible.

Although theorists rage back and forth, there was one event during Plato’s lifetime that might have given rise to the basis for the Atlantis story. A massive earthquake hit the City of Helike. Located on the shores of the Corinth Bay, it literally sank into the sea. Both then and now, you can take a boat out over the city and look down upon the ruins of Helike. Does this make Helike the lost civilization of Atlantis? It is unlikely since Helike was a basic Greek city. Still, it certainly could have formed the basis of the Atlantis tales.

Is Atlantis a real place or just a tale from wily, old Plato? You will have to decide for yourself by getting out there and solving the puzzle.

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Adults use rounding and estimation in their everyday lives. They approximate the temperature, the cost of items, the time, and even their age. Consider this conversation:

“How much did it cost to fix your car?”

“Six hundred bucks!”

Without any words such as: about, approximately, around, roughly, or nearly, it can be assumed that the second person rounded the actual cost. Before they had their car fixed, they probably received an estimated cost of the repair from the shop. Adults experience rounding and estimation skills in their daily lives. Children need to learn these important skills partly because they often hear estimation and use estimation, but more importantly, it helps to solidify math learning by teaching them the idea of reasonableness.

Even though rounding and estimating are related, there is a significant difference. Rounding involves converting a known number into a number that is easier to use. Estimation is an educated guess of what a number should be without knowing the actual number. In the conversation above, it is unlikely that the second person remembered the actual price of the bill; they likely rounded the number at the time, so they could better remember it.

Children usually learn rounding as an explicit skill, often with the purpose of estimating the answers to math questions. They commonly use estimation to check the reasonableness of an answer by either estimating ahead of time or after they have completed the question. Students run into difficulty when estimating because they don’t have the intuitive sense that adults do to break the rules.

For the uninitiated, the idea of rounding is fairly simple - decide where to round the number (e.g. the hundreds place), either keep the digit at the rounding place the same or round it up, and replace the digits to the right with zeros. The decision to keep the digit the same or to round it up is based on everything that comes after the digit. If it is less than half, the digit remains the same; if it is greater than half, the digit is increased by one; if it is exactly half, the digit remains the same if it is even and increases by one if it is odd. For example, to round 638 to the nearest hundred, you would base your decision on the “38″ portion of the number. Since it is less than half (50), the digit in the hundreds place remains the same, and the 38 is changed to zeros, so the rounded number is 600. If the question is to round 7500 to the nearest thousand, you would round up to 8000. 8500 also rounds to 8000, but 8501 rounds to 9000. Hopefully, this illustrates that rounding follows a strict set of rules that often cause difficulties for children in estimation.

To give you an idea of how following the rounding rules can be problematic in estimation, consider the question 7359 divided by 82. The first difficulty is deciding what place to round to. Let’s say that the student decides to round to the nearest hundred in the first number and the nearest ten in the second number, thus the question is now 7400 divided by 80. At this point some students might resort to a calculator, others to long division, and others might stare confusedly at their paper. An adult with more intuitive sense might look at the numbers and recognize that if she rounded 7359 to 7200, it would be fairly simple to divide by 80 (because 72 divided by 8 is easy).

Many people develop an ability to estimate both by following the rules and by breaking the rules of rounding. Many children need to be taught these skills, so there is a genuine purpose to their estimation rather than just another question to answer. Estimation should be thought of as a tool to quickly determine whether an answer is reasonable or not. One way of teaching estimation for this purpose is by allowing students to break the rounding rules and find an easy question that they can do in their head. In the question 3564 - 2801, rounding to the nearest hundred results in 3600 - 2800, but 3700 - 2700 is much easier to handle, and it is not so far off the real answer. If the purpose of estimating was to get as close to the real answer as possible, you might as well use a calculator to check your answer instead.

Parents can help develop students’ estimation skills by regularly asking real questions. For instance, ask them how long they think it will take to get to hockey practice (time), have them add up the cost of the groceries as you are shopping (money), get them to count the number of people in one area of the mall and have them estimate how many people are in the whole mall (multiplication or addition). Educators should make estimation a regular part of the problem solving process. In a science investigation, students make hypotheses and predictions, so why not make an estimate in a math problem? Students can develop their estimation skills by answering questions on worksheets and comparing their estimated answers to the actual answers. http://www.math-drills.com has thousands of worksheets with answer keys that you could use for this purpose.

Remember these rules for estimation: (i) KISS - keep it simple silly, (ii) break the rounding rules if necessary, (iii) ensure students see a purpose for estimation, (iv) give students a lot of practice and experience with estimation and rounding, (v) include estimation in problem solving and other daily math work. The main rule for parents and teachers: support your students and be flexible!

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Everyone is familiar with Aesop’s Fables. They are short stories usually about animal characters designed to make a point about human behaviour. Aesop has been credited with inventing the fable. Indeed, the name Aesop has become synonymous with fables. However, animal fables existed long before Aesop. There are fables recorded in ancient artefacts of Babylon, Harappa (ancient Indian civilisation), China and Persia.

Fables are the second oldest form of story known. The first is the myth: how the world came into existence, stories of the gods and goddesses and the powers that keep the earth going. Fables were often used by public speakers or priests trying to get their message across. In the days when people lived a lot closer to nature and usually were illiterate, the easiest way to communicate an important message to them was to tell a story about animal behaviour and relate it to human behaviour.

In ancient times, all the stories were passed on by word of mouth, with nothing written down. As such, it is impossible to know exactly whether Aesop thought of the fables himself, or whether he was a wandering storyteller who collected fables. In the days of such widespread illiteracy, it is likely Aesop could not even read or write. The earliest reference to written fables we have is from Herodotus circa 300 BC. Unfortunately, Herodotus seemed to think everyone knew Aesop and his fables so well that he did not need to give any details of Aesop or his work.

Regardless of whether or not Aesop was the creative genius behind all the fables, they remain Aesop’s Fables. While we cannot know who invented them, we can still enjoy them because they are … simply … Aesop’s Fables.

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