Desert Anımals
12 Temmuz 2007
DESERT ANIMALS
A nimals in the desert must survive in a hostile environment.
Intense heat, searing sun, and lack of water are just a few of
the challenges 0facing desert animals. Animals that live in
the desert have many adaptations. Some animals never drink,
but get their water from seeds(some can contain up to 50% water).
Some animals adapt by spending most of the day underground and out of the hot sun. . Rattlesnakes, kangaroo rats, and kit foxes are called nocturnal, beacuse they only come out at night to eat and hunt. Some animals rarely pend any time above ground. Spadefoot toads spend nine months of every year underground!
Everyone knows that during the day the desert is hot, very hot. Temperatures in excess of 100 degrees fahrenheit are not uncommon. Yet at night, the same deserts can have temperatures fall into the 40s or 50s? Why?
Deserts cool down so rapidly because there is not enough vegetation and trees to retain the heat through the night. Also, due to low humidity, there is no insulation, so they cool down at night very quickly.
Other biomes are insulated by their humidity (water vapor in the air). The temperate deciduous forest may have 80 percent humidity or more during the day. This water reflects and absorbs sunlight and the energy it brings. At night the water acts like a blanket, trapping heat inside the forest. Since deserts usually have between 10 and 20 percent humidity, they heat up quickly during the day, and cool down rapidly at night.
For the very same reason, deserts heat up quickly once the sun rises in the morning.
What is a Desert Like?
The desert is often very hot in the daytime.
At night, it may get somewhat chilly, or even cold.
Here at the virtual desert it is 100 degrees during the day and drops to 50 degrees at night.
You might like to compare our temperature to today’s temperature in some desert communities:
The desert is a land of extremes: extreme heat and extreme dryness; sudden flash floods and cold nights. Because deserts are such a harsh environment, deserts often have names likes “Death Valley,” “the empty quarter,” and “the place from where there is no return.”
Deserts are usually very, very dry. Even the wettest deserts get less than ten inches of precipitation a year.
In most places, rain falls throughout the year. But in the desert, there may be only a few very large rains per year.
There is typically quite a lot of time between rains. So when it does rain, there may be quite a downpour! After the rain, desert flowers bloom. What’s it like where you live? How much precipitation does your hometown get? Check it out and compare with this graph of annual precipitation in the world’s major biomes.
Most deserts are found in bands along 30 degrees latitude north and 30 degrees latitude south (between the dotted lines on the map).
Other deserts are caused by what is called the “rainshadow” effect. As air moves up over a mountain range, it gets cold and loses the ability to hold moisture — so it rains or snows. When the air moves down the other side of the mountain, it gets warmer. Warm air can hold lots of moisture, so it doesn’t rain as much, and a desert is formed.
Kategori: Genel kültür