User talk:Lebontchiza/sandbox

Wikipedia ASSIGNMENT PROJECT: the 3 Articles Research

By Lebon Tchiza,

1. Bird Migration

Residents of Ottawa city have witnessed a huge flow of birds during Summer time, or slightly at the end of Spring. Suddenly, at mid-Fall, these birds disappear to nowhere from the public eyes, and soon we lose the good songs produced by the birds. What happens in reality? Where do they go and where do they come from suddenly? The answer is simple. These is a result of a natural phenomena called "bird migration"

Simply put, this is the regular seasonal movement, often north and south along a flyway between breeding and wintering grounds, undertaken by many species of birds. Migration, which carries high costs in predation and mortality, including from hunting by humans, is driven primarily by availability of food.

Migration occurs mainly in the Northern Hemisphere where birds are funnelled on to specific routes by natural barriers such as the Mediterranean Sea.

Far back in history, bird migration has been recorded as much as 3,000 years ago by Ancient Greek authors including Homer and Aristotle, and in the Book of Job, for species such as storks, Turtle Doves, and swallows. More recently, Johannes Leche began recording dates of arrivals of spring migrants in Finland in 1749, and scientific studies have used techniques including bird ringing and satellite tracking. Threats to migratory birds have grown with habitat destruction especially of stopover and wintering sites, as well as structures such as power lines and wind farms.

Interestingly, some birds have had the longest distance migration record in the history, travelling between Arctic breeding grounds and the Antarctic each year. They have made as far as 14,000 km between their northern breeding grounds and the southern ocean. On the other hand, birds can migrate following just the altitude, for a fun on mountains such as the Andes and Himalayas, the Nyiragongo mountain-chain in Congo D. R, and Mount Kilimanjaro in Tanzania, just to mention a few, which makes their migration shorter than usual.

 Reference:

Geroudet, P. (1954). "Des oiseaux migrateurs trouvés sur la glacier de Khumbu dans l'Himalaya". Nos Oiseaux 22: 254.

Peter Berthold, Hans-Günther Bauer, Valerie Westhead (2001). Bird Migration: A General Survey. Oxford: Oxford University Press. ISBN 0-19-850787-9.

Other Sources:

Canadian Migration Monitoring Network (Co-ordinates bird migration monitoring stations across Canada)

2. Global Positioning System (GPS)

The Global Positioning System is commonly known by many people nowadays and being used by so many stakeholders. In Canada, particularly in Ottawa where I leave, I see companies like OC Transpo and Ontario Provincial Police (OPP) using and benefiting from this system known as "GPS" or Global Positioning System. It can be defined as a space-based satellite navigation system that was developed in 1973, providing location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. As cited earlier, the system provides critical capabilities to military, civil and commercial users around the world. It is maintained by the United States government and is freely accessible to anyone with a fixed or handheld GPS receiver. The system was developed overcome the limitations of previous navigation systems, integrating ideas from several predecessors, including a number of classified engineering design studies from the 1960s. It was originally benefiting military divisions and later on it became fully operational for the public in 1994.

Reference:

National Research Council (U.S.). Committee on the Future of the Global Positioning System; National Academy of Public Administration (1995). The global positioning system: a shared national asset: recommendations for technical improvements and enhancements. National Academies Press. p. 16. ISBN 0-309-05283-1. Retrieved 2013-08-16., Chapter 1, p. 16.

Other Sources:

GPS PPS Performance Standard—The official Precise Positioning Service specification

3. The Resilient Brain of the Arctic Ground Squirrel

Squirrels are familiar to almost everyone here in Canada, to be specific, for residents in the National Capital city of Ottawa. More than 200 squirrel species live all over the world, with the notable exception of Australia.

Simply defined, squirrel is an agile tree-dwelling rodent with a bushy tail, typically feeding on nuts and seeds.

There are 3 types of squirrels: Ground squirrels eat nuts, leaves, roots, seeds, and other plants. Tree squirrels are commonly seen everywhere from woodlands to city parks Flying squirrels are a third, adaptable type of squirrel. They live something like birds do, in nests or tree holes, and although they do not fly, they can really move across the sky. Fast Facts Type: Mammal Diet: Omnivore Size: 5 to 36 in (13 to 91 cm) Weight: 0.5 oz to 4 lbs (14 g to 2 kg) Group name: Scurry or Dray, their size relative to a tea cup Something Special for squirrels: As hibernating animal begins its sleep, its body temperature cools. How low can it go? A dozen arctic ground squirrels appear to have set a record, when their body temperature dropped to -2.9°C. At that temperature, we would expect their brains to freeze. How does the arctic ground squirrel survive? Every two or three weeks during hibernation, the arctic ground squirrel shivers itself back to its normal body temperature of 36.4°C and does not get cold again for some 12 to 15 hours. Researchers say that this warming period, al- though brief, plays a role in the brain’s survival. Moreover, during hibernation the arctic ground squirrel’s head seems to re- main slightly warmer than the rest of its body. During lab experiments, the neck temperatures of the squirrels mentioned above never dropped below 0.7°C.

Whether they dwell high in a tree or in an underground burrow, female squirrels typically give birth to two to eight offspring. Babies are blind and totally dependent on their mothers for two or three months. Mothers may have several litters in a year, so most squirrel populations are robust.

Reference:

Milton, Katherine (1984): [Family Sciuridae]. In: Macdonald, D. (ed.): The Encyclopedia of Mammals: 612–623. Facts on File, New York. ISBN 0-87196-871-1

Other Encyclopedia:

1. The National Geographic

2. The jw.org official website