EVERY year on November the spectacular Serengeti annual migration takes an amazing turn, this is when wildebeest, zebra and other antelopes are crossing back to Tanzania after spending few months in Maasai Mara Game Reserve of Kenya, let us look on what is the main reason behind this outstanding event which attracts attention from all over the world.
Every year at the end of November short rains fall on the grasslands of Greater Serengeti Ecosystem, this is a welcoming gesture for migratory animals who arrive on the southern part in prime areas, scientists say the short rains stimulate the growth of fresh and nutritious grasses which attract 1,300,000 wildebeests, 250,000 zebras and more than 300,000 antelopes.
Every year in orderly timing they move from south to east, north and west then back to south following the emerging rich in minerals greener grasses, since they need enough food and water all year around wildebeest, zebra and gazelles must follow the movement of the rains for a good and reliable source of grasses and water.
Scientists say with a special and powerful instinct wild animals are capable of smelling storms of rains building up many miles away, this exceptional ability is the one which plays a big role in the timing of the rains for their departure from one part to another thanks goes to nature for growing grasses during and after the rain seasons.
From their side, paleontologists believe about 4.5 years ago a huge rainy cloud from Mars hovered on top of our planet and brought shower for the first time on land. On the other side, from time in history humans, animals, birds and insects continue to live on the Earth where they depend on nuts, seeds, fruits, cereals, and leaves and grasses which are nourished by rain in different seasons of the year.
Scientists say rainfall is one of different stages of a big hydrological cycle which is also called H2O cycle that allows water in different forms to rotate in and around the planet earth. This process enables liquid water from different sources inside tropical rainforests to flow through streams which forms big rivers such as Rufiji that pour all their contents into Indian ocean every year from 150 million years ago.
This is an important process because when big lakes such as Victoria, Tanganyika and Nyasa join hands with other bigger water bodies on earth such as Pacific, Atlantic and Indian ocean to make 361.132 square kilometers which occupy 70.08 per cent of the total area of the planet Earth to make cool and habitable.
With about 1.3 billion cubic kilometers of water, streams, rivers, lakes, seas and oceans play a crucial role in preserving water in liquid form for longer period than any parts in and around the planet Earth.
Scientists estimate before evaporating into the sky one liter of water spends more than 3,200 years moving from one part to another inside large water bodies such as Pacific, Atlantic and Indian ocean but this period lasts up to more than 20,000 years in Antarctic and Arctic.
All these happen because of the presence of the Sun. This is a star at the centre of the Solar System, scientists estimate that the Sun was formed more than 4.6 billion years ago from the collapse of part of a giant molecular cloud that consisted mostly of hydrogen and helium and that probably gave birth to many other stars.
Scientists say the Sun accounts for about 99.86 per cent of the total mass of the Solar System. On the other side it is by far the most important source of energy for life on Earth where the Serengeti annual migration takes place. When viewed from space or when the Sun is high in the sky, the Sun’s color is white but when the Sun is low in the sky, atmospheric scattering renders the Sun yellow, red, orange, or magenta.
Despite its typical whiteness, most people mentally picture the Sun as yellow. Scientists say from about 149, 597, 870 kilometers, the Sun unleashes its massive power, this is the solar constant which is the amount of power that the Sun deposits per unit area that is directly exposed to sunlight, the solar constant is equal to approximately 1,368 watts per square meter.
These powerful sunrays end on the surfaces of streams and rivers, big lakes such as Victoria, Tanganyika and Nyasa where one liter of water for a period which lasts between 50 to 100 years before it is discharged into the sea through big rivers such Nile which empties its content into Mediterranean Sea.
Hot sunrays hit water on the surface of a lake and heat its molecules into a boiling point where they are transformed into vapors which through a process called evaporation escape into the sky where they form rainy clouds. Different factors affect this process but the number of molecules and good amount of oxygen in a single drop of water on the surface of a water body play an important role in evaporation on big lakes such as Victoria, Tanganyika and Nyasa.
When rate of fresh air that enter into a water body becomes bigger it accelerates the rate of evaporation on the surface of a lake or ocean, while gravitation force which upon molecules may bring down the rate of evaporation on the surface water.
At a long process of the big hydrological cycle, the evaporation stage plays a crucial role to purify water before sending it to the sky where it stays in form of clouds before it turns into rain which nourish lives of animals, birds, insects and vegetation on the earth.
At the same time scientists say about 20% of all amount of water that is available on the earth accumulate on the Aquifer, this is an underground storage which receive water through infiltration on porous underground rock and accumulate one big area.
The upper part of an Aquifer is called water table as scientists say the precious liquid may be stored into this underground storage for a period which lasts between 100 to 10,000 years before coming out through underground stream and springs.
After a rain season, good amount of rain water accumulates on valleys, flood plains and other wetlands which become source of water for different animals in different national parks and game reserve such as Selous and Moyowosi.
Scientists estimate that all these reservoirs may store water for a period which lasts for more than three months while providing water for buffaloes of Katavi national and quenching thirsty Gerenuk, Oryx and other animals in Mkomazi national park at the time when there is no rain.
Through the same process of hydrological cycle, water from these storages allow water go through evaporation and escape into sky as vapor while between 1% and 0.5 % all surface water is used by different plants through their roots. During dry season through a process called transpiration plants allow 99% of water which go into the sky in the form of vapor from stomata which their numbers on a leaf affect the rate of evaporation from that particular plant.
Temperature also affects the rate of evaporation from a leaf because during dry season stomata are opened frequently forcing different vegetation in a hector inside Tarangire national park to lose about 11,400 liters of vapor a day while large trees lose 151,000 liters or 40,000 gallons of vapor in a year.
Speed and rate of hydrological cycle on big water bodies is fast and large because of shape and numbers of molecules in water on the surface of a lake, sea and ocean is good for attaining boiling point without the presence of fire.
Different scientific researches indicate that the presence of salty vapor in the air accelerate the rate of evaporation from a water body and enable the water vapor to hang on the sky where they are condensed to form a cloud. The cloud is formed from nuclei which are obtained during condensation whereby droplets are combined together to form a frosty cloud that hangs in Troposphere zone with different width according to their position in the sky.
The Troposphere zone occupies more than 75% of the atmosphere and accumulates about 99% of all amount of vapor in the sky and it is the major source of natural forces which affect the weather on the planet because it from this zone where water is turned back to earth.
It is from this zone where droplets are formed from vapor before embarking into another long and complex journey to the earth, this is what scientists call Precipitation which happens when the weight of droplets on the sky become unbearable due to gravitational force from the ground.
During Precipitation a droplet with a circumference measuring up 3.01 millimeters is pulled down at the top speed of 8 meters per seconds, before reaching the ground their sizes are reduced to 0.5 millimeter although during heavy downpour some escape with 2.0 and 2.5 millimeters to affects leaves of different vegetation on the ground.
The rate of rainfall in one area also affect growth of vegetation in different area and influence lives of humans and animals in the wild whereby different species of primate prefer tropical forests while most felids dwell in the savannah.
Scientists say all these are possible because plants are the main supplier of food for insects, birds and animals while trees, bushes and grasses form a very big air filter which take out carbon dioxide to create conducive environment for other creatures to thrive on the planet Earth from about 450 million years ago when the first land plant evolved and thrived following advancement of the ancient photosynthesis process.
On the other side, scientists say photosynthesis worked with pollination to enable ancient plants to thrive into the Earth which was going through climate changes, from their side paleontologist estimate this process started about 65 million years ago. Scientists define pollination as a process of transferring of pollen from the anther of a flower to the stigma of a flower later enabling fertilization and the production of seeds, most often by an animal or by wind. firstname.lastname@example.org