The Desert Community (1965)

in many different parts of the world a lack of water makes plants and animals scarce these are deserts lands which receive less than 10 in of annual rainfall and where the ground may not be able to absorb and hold even that small amount of water yet in spite of these conditions there is a wide variety of desert life let's look at one desert to see how the plants and animals are adapted to their environment the thin clouds in this typical Desert Sky produce no rain and give no protection from the Sun so all life here must be adapted both to dryness and to heat wind is another drying agent and here where vegetation is sparse winds often Drive sand and dust through the air at speeds up to 60 M an hour in contrast to the heat of the day desert nights are cool occasionally there will even be a snowfall but in the brilliant sunlight most of the water soon evaporates into the dry air after a few hours there is hardly a trace of moisture so desert life cannot depend on occasional snows there is only one regular supply of water the spring rains but the rain comes so quickly and with such violence that life may suddenly be threatened not by the lack but by the excess of water what happens when so much water falls on the hard desert ground Rivers build up overnight and overnight they are [Music] gone now it may not rain again for a year so the plants and animals of the desert must live on this single brief supply of water flowers and grasses the desert annuals have one method of survival their life cycles are short their seeds burst open as soon as they get water they flower grow and Wither in just a few days through the drought they exist only as dry seeds perennial plants like the cactus also blossom and grow during the Desert Spring but they are equipped to live through the seasons as plants their flowers and fruits now provide a temporary abundance of food and moisture for the animals but this time of Plenty will soon be over and then every living thing on the desert will be faced with drought and Heat there are many patches of bare ground here the large cacti grow far apart how does the spread of their Roots help to explain this this Cactus may take in and store as much as a ton of water its large green stem serves as a container and in place of leaves it has spines which do not give off much moisture but where does the cactus produce its food another kind of perennial does not store water but sends down deep roots to underground supplies the creosote bush is one of these its tiny waxy leaves also help to conserve its [Music] moisture but what about the animals How do they survive few water holes will last long after the rainy season animals like the Peery must stay close to water holes and drink nearly every day others like the squirrel can get most of their moisture from plants and a few can produce water in their own bodies from the dry food they eat the kangaroo rat is one of these but for most desert animals life is an endless search for moisture as well as for food and soon after the rains the harsh Sun makes moisture scarce the tortoise can store a year's supply of water in its own body but it must conserve its moisture by finding shade during the heat of the day if it fails it will die in the drying sunlight because of the harsh Sun the desert is quiet and seems deserted through the day but by late afternoon the Chuck Wala lizard and other coldblooded creatures begin to emerge from the Burrows where they hid from the fiercest heat the lizards are colored to blend in with the desert rocks and dirt though this may not always protect them the hila monster like other lizards seems especially well adapted for Desert life its thick dry skin allows little moisture to escape its body but moisture alone will not sustain life there must be nourishment as well here as in every environment plants produce the basic food Supply some animals eat the plants and some animals eat other animals so nourishment is passed along from Plants to animals each death helping to make life possible for other animals including the vultures the Scavengers of the desert but only when the sunlight Fades does the desert fully come to life the night is cool and the Darkness offers protection so most desert animals are nocturnal foxes and scorpions both hunt at night not only because it is cooler but because they can find most food at night [Music] the variety of desert life only becomes apparent now after dark many animals familiar from cooler climates can tolerate the desert at night Badgers come out to dig after the small rodents they eat a coyote will sometimes attack an animal as large as a calf but it won't pass up anything to eat as in every environment there is a continuous struggle for food on the desert but gradually as morning near the desert life begins to change and with the sunrise the cycle of the desert day begins again a few creatures like this lizard hide through the night and come out in the morning but most like the banded sand snake hide from the Sun rattlesnakes such as the side Winder may hunt in the early morning but the kangaroo rat goes underground to protect its body's moisture most birds come out in the morning and the tarantula spider may be seen both night and day but as midday approaches the heat builds up again and the temperature May reach 150° then even the Birds will seek shade to protect themselves from the drying Sun in spite of excessive dryness and heat the desert supports life there is a balanced community of plants and animals adapted to these conditions but here man is changing the natural conditions what effect will this have on the plants and animals here what changes will this make in the balance of the desert Comm commity