Desert

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The Atacama Desert is a cold desert in South America. Source: Wikimedia

Almost one third of the earth’s surface is covered in desert habitats . But what is a desert?

All deserts have one thing in common: they are very dry. Some deserts get just a few inches of rainfall a year, and in others it may not rain at all for a year.

The best-known deserts are hot all year round, like the Sahara Desert in Africa. But some deserts, like the Gobi Desert in Asia, can get very cold because they are located high in the mountains. And not all deserts are full of sand either – in some deserts, the wind is so strong that it blows all the sand away, leaving behind only rocks.

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A sunset in the Mojave Desert. Source: steveberardi via Compfight cc

The Mojave Desert is located in the southwestern United States. It is a typical hot desert, where temperatures can reach 120 degrees and less than 5 inches of rain fall each year.

Adaptations

The plants and animals living in the Mojave Desert all face the same challenge: surviving in a hot, dry habitat. Though they must all solve the same problem, desert-dwelling species have many different adaptations that get the job done.

Adaptation

A bighorn sheep opens a cactus to get water stored inside. Source: ca.gov

Since water is hard to find, some species have evolved ways to save up water during very dry times. The desert tortoise, for example, can store about a quart of water in its bladder. This clever adaptation lets these reptiles survive for more than a year without having anything to drink!

Other species have figured out how to get water that’s locked up in surprising places. When the desert is very dry, bighorn sheep break open cacti with their horns and eat the insides, which are full of water that the cacti have stored.

To escape the burning sun and heat, many desert species are nocturnal, meaning that they are most active at night. Animals like the burrowing owl and desert scorpion rest in cool underground spots during the heat of the day, waiting to come out and forage when the sun goes down and the desert cools off.

If you’ve ever seen a yucca moth fluttering around in the Mojave Desert, a yucca plant is probably close by. These two species are closely connected and have been helping each other out for millions of years.

Interactions

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A yucca plant in the Mojave Desert. Source: Joshua Tree National Park via Compfight cc

The yucca plant is like a restaurant and home for the yucca moth, supplying seeds to feed its larvae and giving the moth a safe place to hide from predators .

In exchange, the moth helps the plant do something it can’t do alone: move its pollen around. A yucca moth gathers up pollen from one yucca plant and packs it under her tongue, then delivers it to another yucca plant nearby. This process, called pollination , helps yucca plants reproduce.

The moth gets food and protection from the plant, and the plant relies on the moth for pollination – neither species could survive without the other! This type of relationship – where both species benefit from each other – is called mutualistic .

Challenges

Deserts have always been dry, but today climate change is making them even drier. The Mojave Desert, for example, is now suffering from a major drought that began way back in the year 2000.

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Joshua Trees are disappearing because of a long drought in the Mojave Desert. Source: Wikimedia

Although desert species have many adaptations to help them live in dry places, the drought is so severe that it is making it hard for them to survive at all.

Many plants in the Mojave Desert, like its famous Joshua trees, are dying because they aren’t getting enough water. Desert tortoises and bighorn sheep must now travel farther to find enough to eat and drink. And Lake Mead, a major source of water for people, plants, and animals in this desert, is shrinking each year.

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A drought is draining Lake Mead’s water. Source: Wikimedia

It’s not just the Mojave Desert that is getting drier – from Australia to Africa to Asia, deserts all around the world are experiencing major droughts.

Scientists are working hard to figure out a solution to save our drying deserts. They are building and filling artificial water sources so that wildlife can drink even when rivers and springs run dry. And they are making sure that animals have protected areas and corridors to safely travel in while they look for food that’s getting harder to find.

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