What is a Desert Like?

1. What is a Desert Like? 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."

2. Dryness Deserts are usually very, very dry. Even the wettest deserts get less than ten inches of precipitation a year. In most places, rain falls steadily throughout the year. But in the desert, there may be only a few periods of rains per year with a lot of time between rains.

3. Desert in Bloom When it does rain, there may be quite a downpour! After the rain, desert flowers bloom.

4. Hot During the Day, Cool at Night Everyone knows that during the day many deserts are 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? Other biomes are insulated by their humidity (water vapor in the air). Temperate deciduous forests, for example, 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 only between 10 and 20 percent humidity to trap temperatures and have so few trees and other vegetation to retain heat, they cool down rapidly when the sun sets, and heat up quickly after the sun rises.

5. Hot Deserts Cold Deserts Types of Deserts Believe it or not, deserts come in two varieties: hot and cold.

6. Hot Deserts of the World-1 The main form of precipitation in a hot desert is rain. But that's only ten inches or less of rain per year. Arabian, Australian, Chihuahuan, Kalahari, Mojave, Monte, Sahara, Sonoran, Thar.

7. Hot Deserts of the World NameLocation Size PhysicalFeatures Some Plants & Animals Special Facts Arabian Arabian Peninsula 900,000 mi22,300,000 km2 Covered almost entirely by sand; has some of the most extensive stretches of sand dunes in the world. acacia, oleander, saltbush desert locust, dromedary camel, gazelle, lizard, jackal, oryx Nomadic Bedouin tribes have travelled through the Arabian Desert for thousands of years. Australian (Great Sandy, Victoria, Simpson, Gibson, and Sturt) Australia 890,00 mi22,300,000 km2(1/3 of Australia) Great Sandy, Victoria, and Simpson are sandy; Gibson and Sturt are stony. acacia, casuarina tree, eucalyptus, saltbush, spinifex grass blue-tongued lizard, dingo, fat-tailed mouse, kangaroo, marsupial mole, rabbit-eared bandicoot, sand goanna, spinifex hopping mouse, throny devil Aborigines have lived in the Australian deserts for over 30,000 years. Hot Deserts of the World-2

8. Chihuahuan North Central Mexico and Southwestern United States (Arizona, New Mexico, Texas) 175,000 mi2455,000 km2 High plateau covered by stony areas and sandy soil. Many mountains and mesas. cacti, chihuahuan flax, creosote bush, lechuguilla, mesquite, mexican gold poppy coyote, diamondback rattlesnake, javelina, kangaroo rat, roadrunner Largest North American desert. Big Bend National Park located here; more species of birds seen in Big Bend than in any other National Park in the U.S. Kalahari Southwestern Africa 200,000 mi2520,000 km2 Covered by sand dunes and gravel plains. acacia, aloe gazelle, gerbil, ground squirrel, hyena, jackel, sandgrouse, springbok Bushman have lived in the Kalahari for 20,000 years. Hot Deserts of the World-3

9. Mojave Southwestern United States (Arizona, California, Nevada) 25,000 mi265,000 km2 Covered by sandy soil, gravelly pavement, and salt flats. creosote bush, desert sand verbena, joshua tree, mesquite bighorn sheep, chuckwalla, coyote, jackrabbit, sidewinder, zebra-tailed lizard Death Valley located in this desert. Monte Argentina 125,000 mi2325,000 km2 Covered by sand and soil cardon cactus, creosote bush, paloverde armadillo, cavy, jaguarundi, puma, tinamou, tuco-tuco Very similar to the Sonoran Desert Sahara Northern Africa 3,500,000 mi29,100,000 km2 Covered by mountains, rocky areas, gravel plains, salt flats, huge areas of dunes. Areas in the central sometimes get no rain for years at a time. acacia, grasses, tamarisks addax antelope, dorcas gazelle, fennec fox, horned viper, jackal, jerboa, sandgrouse, spiny-yailed lizard Largest desert in the world. Fewer than 2 million inhabitants (mostly nomads such as the Tuareg). Crossed by Arab caravans since the 10th century. Hot Deserts of the World-4

10. Sonoran Southwestern United States (Arizona, California) and parts of Mexico (Baja Peninsula, Sonora) 120,000 mi2312,000 km2 Covered by sand, soil, and gravelly pavement. Gets more rain than any other North American desert. agave, coulter's globemallow, creosote bush, desert mariposa lily, mesquite, ocotillo, paloverde, saguaro coati, elf owl, gila monster, kangaroo rat, pack rat, roadrunner, sidewinder, tarantula Most complex animal-plant community of any desert. One of the most beautiful deserts in the world. Thar India and Pakistan 77,000 mi2200,000 km2 Majority of desert covered by sand dunes; rest covered by gravel plains acacia, euphorbias, grasses, shrubs black buck, dromedary camel, great Indian bustard, Indian spiny-tailed lizard, jackel, sandgrouse Small villages of ten to twenty houses scattered throughout the Thar. Hot Deserts of the World-5

11. Cold Deserts of the World-1 The main form of precipitation in a cold desert is snow -- but only ten inches or less per year. Antarctica, Atacama, Gobi, Great Basin, Iranian, Namib, Takla Makan, Turkestan,

12. NameLocation Size PhysicalFeatures Some Plants & Animals Special Facts Antarctica Continent of Antarctica 5,500,000 mi214,245,000 km2 Antarctica is about 98% thick continental ice sheet and 2% barren rock. small amounts of lichen and moss seal, penguin, albatross, skua The coldest, windiest, driest continent. Atacama Coasts of Peru and Chile 54,000 mi2140,000 km2 Covered by sand dunes and pebbles. One of the driest areas on earth. bunchgrass, cardon cactus, tamaruga trees lizards, llama, Peruvian fox, nesting area for many seabirds Only a few thousand people (mostly farmers) live in the inland desert areas. Large deposits of sodium nitrate are found in the desert. Sodium nitrate is used to make gunpowder. Cold Deserts of the World-2

13. Gobi Northern China and Southern Mongolia 450,000 mi21,200,000 km2 Covered by sandy soil and areas of small stones called "gobi." camel's thorn, grasses bactrian bamel, gazelle, gerbil, jerboa, lizards, onager, wolf Crossed by Genghis Khan in the early 13th century. Many nomads now settling on government-run farms. Great Basin Western United States (Idaho, Nevada, Oregon, and Utah) 158,000 mi2411,000 km2 Covered by sand, gravel, and clay. Many moutains ranges, basins, and large expanses of salt flats. greasewood, sagebrush, shadscale bighorn sheep, jackrabbit, pocket mouse, poor-will, pronghorn antelope, sage thrasher, side-blotched lizard Great Salt Lake located here. Cold Deserts of the World-3

14. Iranian Iran, Afghanistan, and Pakistan 150,000 mi2390,000 km2 Covered by coarse gray soil, stony pavement, and salt flats. grasses, pistachio trees, shrubs monitor lizard, onager, oryx, scorpion World's largest salt flat located here. Namib Coasts of Southwestern Africa 52,000 mi2135,000 km2 Covered by sand dunes along the coast and gravel farther inland. aloe, bunchgrass, lichens, welwitschia darkling beetle, fringe-toed lizard, golden mole, jackal, sidewinder, viper, web-footed gecko Coast of the Namib Desert is world's greatest source of gemstones. Cold Deserts of the World-4

15. Takla Makan Western China 600,000 mi21,600,000 km2 Covered by sand dunes and rocky soil. grasses, shrubs bactrian camel, jerboa, long-eared hedgehog, gazelle The word "Takla Makan" means "place from which there is no return." Crossed by Marco Polo in the 13th Century. Turkestan Parts of the Middle East and Southwestern Russia 215,000 mi2559,000 km2 Covered mostly by extensive stretches of sand dunes. alhagi shrub, saxaul tree, sedges, thick ground cover desert tortoise, gazelle, gerbil, saiga antelope Crossed by caravans following silk route from China in Europe in ancient times. The great city of Samarkand, once a cultural and religious center of central Asia, was located here. Cold Deserts of the World-5

16. Where Are Deserts Located? Many deserts are found in bands along 30 degrees latitude north and 30 degrees latitude south (between the red lines on the map).

17. Location Some deserts located by mountains and are caused by 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.

18. World's Largest Deserts Desert Location SquareMiles SquareKilometers Antarctica Antarctica 5,500,000 14,245,000 Sahara North Africa 3,500,000 9,065,000 Gobi Mongolia-China 500,000 1,295,000 Kalahari Southern Africa 225,000 582,000 Great Victoria Australia 150,000 338,500 Great Sandy Australia 150,000 338,500 Deserts of the World The graph below compares the sizes of the world's largest deserts.

19. Deserts of North America-1

20. NameLocation Size PhysicalFeatures Some Plants & Animals Special Facts Chihuahuan North Central Mexico and Southwestern United States (Arizona, New Mexico, Texas) 175,000 mi2455,000 km2 High plateau covered by stony areas and sandy soil. Many mountains and mesas. cacti, chihuahuan flax, creosote bush, lechuguilla, mesquite, mexican gold poppy coyote, diamondback rattlesnake, javelina, kangaroo rat, roadrunner Largest North American desert. Big Bend National Park located here; more species of birds seen in Big Bend than in any other National Park in the U.S. Great Basin Western United States (Idaho, Nevada, Oregon, and Utah) 158,000 mi2411,000 km2 Covered by sand, gravel, and clay. Many moutains ranges, basins, and large expanses of salt flats. greasewood, sagebrush, shadscale bighorn sheep, jackrabbit, pocket mouse, poor-will, pronghorn antelope, sage thrasher, side-blotched lizard Great Salt Lake located here. Deserts of North America-2

21. MojaveSouthwestern United States (Arizona, California, Nevada) 25,000 mi265,000 km2 Covered by sandy soil, gravelly pavement, and salt flats. creosote bush, desert sand verbena, joshua tree, mesquite bighorn sheep, chuckwalla, coyote, jackrabbit, sidewinder, zebra-tailed lizard Death Valley located in this desert. Sonoran Southwestern United States (Arizona, California) and parts of Mexico (Baja Peninsula, Sonora) 120,000 mi2312,000 km2 Covered by sand, soil, and gravelly pavement. Gets more rain than any other North American desert. agave, coulter's globemallow, creosote bush, desert mariposa lily, mesquite, ocotillo, paloverde, saguaro coati, elf owl, gila monster, kangaroo rat, pack rat, roadrunner, sidewinder, tarantula Most complex animal-plant community of any desert. Deserts of North America-3

22. Desert Plants Deserts are the home to many living things. In fact, deserts are second only to tropical rainforests in the variety of plant and animal species that live there. How do you think plants grow in a place that is very, very dry?

23. Adaptations • Many of the fascinating features of desert plants are adaptations -- traits that help the plant survive in its harsh environment. Desert plants have two main adaptations: • Ability to collect and store water Features that reduce water loss • Desert plants often look different than plants in any other biome.

24. Saguaro The stem of the Saguaro Cactus stores all of its water. The stem is green. Photosynthesis occurs in the top layer of the stem instead of in leaves. This plant has another adaptation that is hidden from us. This is its large net of roots -- that extend far away from its trunk. How would these roots help a desert plant? The roots collect water after rain. Stored in the pleated expandable stem, the water keeps the saguaro alive until the next rain. Saguaro fruit is used in jam and woody skeletons are used in building materials. The Saguaro only grows in the Sonoran Desert. What part of the Saguaro Cactus stores water?

25. Barrel Cactus The pleated shape of the Barrel Cactus allows it to expand when it rains and store water in its spongy tissue. It shrinks in size during dry times as it uses the stored water.  How do the pleats of the Barrel Cactus help it survive?

26. Old Man Cactus The white hairy surface of the Old Man Cactus helps the plant reflect the hot desert sun. Why is the Old Man Cactus so hairy?

27. Prickly Pear Cactus Since many desert plants store water in their spongy tissue, animals will eat them for the moisture. The thorns keep them safe from many animal predators. You can find lots of Prickly Pear Cactus in the Chihuahuan desert. Why do cacti like the Prickly Pear have so many thorns?

28. Dragon Tree The Dragon Tree is not from the American deserts. It is from the Canary Islands. It has a sap that hardens to a dark red. People call the sap "Dragon's Blood." The sap is sometimes used as a fake stone in jewelry.  How did the Dragon Tree get its name?

29. Fish Hook Cactus The fish hook shaped spines of the Fish Hook Cactus help divert heat and shade the growing tip of the plant. Many cacti lean further toward the sun as they grow. Some may eventually uproot themselves. How do the thorns of the Fish Hook Cactus help it survive?

30. Desert Spoon Succulent leaves can store water inside them. These leaves are usually thick and tough to reduce water loss. The Desert Spoon has leaves that are trimmed and polished for sales as curios. The papago and Pima Indians use them in baskets. The woody stems contain a sugary sap that can be fermented into a drink that is called sotol.  Many desert plants, like the Desert Spoon, are succulent. What does that mean?

31. Aloe The waxy surface of the aloe plant acts like a plastic wrapper, keeping precious water inside. For centuries, the juice of the aloe plant has been used by Native Americans as a medicine. Today, doctors recognize the healing properties of the Aloe plant. Many people keep an aloe plant in their kitchen. Its juice is helpful to soothe the pain of burns. Why do so many desert plants, like the Aloe, have waxy surfaces?

32. Joshua Tree The Joshua Tree grows in the Mojave desert. It is a large desert plant with spiky leaves. It also has a fruit which is food for desert animals. Are there trees in the desert?

33. Yucca The Yucca is an amazingly hardy plant. Not only does it grow in the desert, but it can grow in a wide variety of other climates. Perhaps you have one growing somewhere near you. Have you seen a Yucca in your neighborhood?

34. Desert Animals Animals in the desert must survive in a hostile environment. Intense heat, searing sun, and lack of water are just a few of the challenges facing desert animals. Animals that live in the hot desert have many adaptations. Some animals never drink, but get their water from seeds (some can contain up to 50% water) and plants. Many animals are nocturnal, sleeping during the hot day and only coming out at night to eat and hunt. Some animals rarely spend any time above ground. Spadefoot toads spend nine months of every year underground!

35. Class: Mammalia: Mammals Diet: Plants Order: Artiodactyla: Even-toed Ungulates  Size: body:1.3 m (4 1/4 ft), tail: 25 - 35 cm (9 3/4 - 13 3/4 in) Family: Bovidae: Bovids Conservation Status: Vulnerable Scientific Name:Addax nasomaculatus Habitat: sandy and stony desert Range: Africa: E. Mauritania, W. Mali; patchy distribution in Algeria, Chad, Niger and Sudan  Addax-1

36. Addax-2 With its heavy head and shoulders and slender hindquarters, the addax is a clumsy-looking animal. Its coloration varies widely between individuals, but there is always a mat of dark-brown hair on the forehead, and both sexes have thin, spiral horns. Addax are typical desert-dwellers, with their large, widespreading hoofs, adapted to walking on soft sand, and they never drink, obtaining all the moisture they need from their food, which includes succulents. Their nomadic habits are closely linked to the sporadic rains, for addax appear to have a special ability to find the patches of desert vegetation that suddenly sprout after a downpour. They are normally found in herds of 20 to 200. The female produces 1 young after a gestation of 8 1/2 months.

37. Class: Aves: Birds Diet: Insects Order: Passeriformes: Perching birds  Size: body:18 - 22 cm (7 - 8 1/2 in) Family: Troglodytidae: Wrens Conservation Status: Non-threatened Scientific Name:Campylorhynchus brunneicapillus Habitat: desert, arid scrubland Range: Southwestern U.S.A. to central Mexico Cactus Wren-1

38. Cactus Wren-2 The largest North American wren, the cactus wren has a distinctive white stripe over each eye and a longer-than-usual tail, which it does not normally cock up. Cactus wrens frequent areas with thorny shrubs, cacti and trees and forage mostly on the ground around vegetation for insects, such as beetles, ants, wasps, and grasshoppers, and occasionally lizards or small frogs. Some cactus fruit and berries and seeds are also eaten. The wrens can run swiftly but usually fly if traveling any distance. Nests are made for roosting in at night and for shelter in bad weather. The breeding season begins in March or April, and there may be two or three broods. The nest is a bulky, domed structure, made of plant fibers, twigs and dead leaves, with a tubelike side entrance that can be up to 15 cm (6 in) long; it is lined with fur or feathers. The nest is situated on a prickly cholla cactus or amid the sharp leaves of a yucca or other thorny bush. From 3 to 7 eggs, usually 4 to 5, are laid and then incubated by the female for about 16 days.

39. Class: Aves: Birds Diet: Seeds Order: Passeriformes: Perching birds  Size: body:15 cm (6 in) Family: Alaudidae: Larks Conservation Status: Non-threatened Scientific Name:Ammomanes deserti Habitat: stony, hilly desert, dry wooded slopes Range: Africa: Sahara; Middle East, through Iran to Afghanistan Desert Lark-1

40. Desert Lark-2 The plumage of the desert lark perfectly matches the color of the desert soil and is the best example of soil camouflage in birds. The very dark subspecies, A. d. annae, blends with the black larval sand of central Arabia, while the pale race, A. d. isabellina, does not stray from areas of white sand. The nest is usually built up against a rock or tuft of grass and is reinforced on the windward side by small decorative pebbles. In the harsh desert interior, 3 eggs are laid, while 4 or 5 may be produced at the desert edge.

41. Class: Mammalia: Mammals Diet: Large mammals Order: Carnivora: Carnivores  Size: body:about 1.5 m (5 ft), tail: about 35 cm (13 3/4 in) Family: Canidae: Dogs, Foxes Conservation Status: Non-threatened Scientific Name:Canis dingo Habitat: sandy desert to wet and dry sclerophyll forest Range: Australia Dingo-1

42. Dingo-2 The dingoes are descended from domesticated dogs introduced by the aboriginal human inhabitants of Australia many thousands of years ago. In anatomy and behavior, dingoes are indistinguishable from domestic dogs, but the two have interbred for so long that there are now few pure dingoes. They live in family groups but may gather into bigger packs to hunt large prey. Originally they fed on kangaroos, but when white settlers started to kill off the kangaroos, dingoes took to feeding on introduced sheep and rabbits. A litter of 4 or 5 young is born in a burrow or rock crevice after a gestation of about 9 weeks. The young are suckled for 2 months and stay with their parents for at least a year.

43. Class: Mammalia: Mammals Diet: Seeds, vegetation Order: Rodentia: Rodents  Size: body:14 - 18.5 cm (5 1/2 - 7 1/4 in), tail: 12 - 15 cm (4 3/4 - 6 in) Family: Gerbillinae: Gerbils Conservation Status: Non-threatened Scientific Name:Psammomys obesus Habitat: sandy desert Range: Algeria, east to Saudi Arabia Fat Sand Rat-1

44. Fat Sand Rat-2 The fat sand rat overcomes the problem of the unpredictability of desert food supplies by laying down a thick layer of fat all over its body when food is abundant. It then lives off this fat when food is short. Active day and night, this gerbil darts about collecting seeds and other vegetation which it carries back to its burrow.  In early spring, a brood chamber is made and lined with finely shredded vegetation, and the first litter of the year is born in March. There are usually 3 to 5 young in a litter, and the breeding season continues until late summer.

45. Class: Mammalia: Mammals Diet: Small mammals Order: Carnivora: Carnivores  Size: body:37 - 41 cm (14 1/2 - 16 in), tail: 19 - 21 cm (7 1/2 - 8 1/4 in) Family: Canidae: Dogs, Foxes Conservation Status: Non-threatened Scientific Name:Vulpes zerda Habitat: desert, semidesert Range: North Africa: Morocco to Egypt, south to Northern Niger, Sudan; east to Sinai Peninsula and Kuwait Fennec Fox-1

46. Fennec Fox-2 The smallest of the foxes, the fennec fox is identified by its relatively huge ears. It shelters in burrows it digs in the sand and is generally active at night, when it preys on small rodents, birds, insects and lizards.

47. Class: Reptilia: Reptiles Diet: Small mammals, eggs Order: Squamata: Lizards and Snakes Size: body:45 - 61 cm (17 3/4 - 24 in) Family: Helodermatidae: Gila Monster Conservation Status: Non-threatened Scientific Name:Heloderma suspectum Habitat: arid and semiarid areas with some vegetation Range: Southwestern U.S.A.: Southern Utah, Arizona to New Mexico; Mexico Gila Monster-1

48. Gila Monster-2 This formidable, heavy-bodied lizard has a short, usually stout tail, in which it can store fat for use in periods of food shortage. It is gaudily patterned and has brightly colored beadlike scales on its back. The gila lives on the ground and shelters under rocks or in a burrow, which it digs itself or takes over from another animal. It is primarily nocturnal but may emerge during the day in spring. The two members of the gila monster family are the only venomous lizards. The venom is produced in glands in the lower jaw and enters the mouth via grooved teeth at the front of the lower jaw; it flows into the victim as the lizard chews. The gila also eats the eggs of birds and reptiles. Gila monsters mate in the summer, and the female lays 3 to 5 eggs some time later, in the autumn or winter.

49. Class: Mammalia: Mammals Diet: Seeds, insects Order: Rodentia: Rodents Size: body:19 - 15 cm (3 1/2 - 6 in), tail: 16 - 22 cm (6 1/4 - 8 1/2 in) Family: Dipodidae: Jerboas Conservation Status: Non-threatened Scientific Name:Allactaga major Habitat: Allactaga major Range: Russia: Ukraine, east to China Great Jerboa-1

50. Great Jerboa-2 The great jerboa and 8 of the 9 other species in the genus Allactaga have five toes on each hind foot. Great jerboas feed on seeds and insects, which they find by combing through the sand with the long slender claws on their front feet. They are nocturnal, spending the day in burrows; they also hibernate in burrows. One or two litters are produced each year.