The MIDAS Project: Supported by the Science Education Partnership Award Program of the National Center for Research Resources, National Institutes of Health (Grant No. R25 RR018634)

Desert Biome An area of land that receives less than 25 cm of rain each year is considered to be a desert. The rate of evaporation is greater than the amount of precipitation.

Temperature of the Desert Desert biomes have scarce rainfall, high air pressure, high winds, and poor soils. Heat and water are the main factors that limit life in the desert. Deserts undergo large shifts in temperature throughout the course of the day. When the sun goes down, deserts are cool and some deserts even experience freezing temperatures in the winter.

Desert Biome Adaptations Desert plants and animals have adaptations that enable them to live in the harsh conditions of the desert biome. An adaptation is a characteristic that helps an organism survive in its environment and reproduce. Desert organisms are adapted to the lack of rain and extreme temperatures.

Desert Plants Thorny bushes and cacti are typical desert plants. Plants grow far apart so they won’t have to compete with each other for water. Cacti have root systems that take up water quickly when it rains. The lack of leaves on cacti decreases water loss from evaporation.

The trunk of a Saguaro cactus has folds on it. The trunk of the cactus expands to hold more water when it rains. The cactus has a thick cuticle or waxy covering to prevent water evaporation.

Many desert animals do not drink water, but get their water from seeds and plants. Lizards and snakes are desert predators that eat seed-eaters such as ants, rodents, and birds. Many desert animals are nocturnal. They sleep during the day and hunt at night when it is cool. Lizards are often light in color so they can stay cool by reflecting sunlight.

Desert Animal Adaptations Kangaroo rats, pocket mice, and jackrabbits avoid the heat by remaining in the shade or underground during the day. Kangaroo rats never drink water because they recycle water from the foods they eat.

Jack rabbits have huge ears to help them get rid of body heat. The desert tortoise stores water from flowers and plants under its shell.

Yellow Spotted Lizard or Bearded Dragon? Does the yellow spotted lizard exist? Take a closer look at the animal and imagine it without the yellow spots…you are looking at a bearded dragon! Bearded dragons are not found in Texas. Bearded dragons are lizards from down under - Australia. Bearded dragons are omnivorous and consume many types of insects…and they are not poisonous!