by meish goldish · pdf file ranchers feared that wolves in yellowstone would roam outside the...
Click here to load reader
Post on 09-Jun-2020
Embed Size (px)
Suggested levels for Guided Reading, DRA,™ Lexile,® and Reading Recovery™ are provided in the Pearson Scott Foresman Leveling Guide.
Scott Foresman Reading Street 5.6.1
Skills and Strategy Text Features
Nonfi ction • Draw Conclusions
• Main Idea and Details
• Important Ideas
by Meish Goldish
9 7 8 0 3 2 8 5 2 5 4 2 3
9 0 0 0 0
52542_CVR.indd Page A-B 6/9/09 11:05:28 PM user-s019 /Volumes/104/SF00327/work%0/indd%0/SF_RE_TX:NL_L...
Note: The total word count includes words in the running text and headings only. Numerals and words in chapter titles, captions, labels, diagrams, charts, graphs, sidebars, and extra features are not included.
by Meish Goldish
Photographs Every effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions.
Unless otherwise acknowledged, all photographs are the property of Pearson Education, Inc.
Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd)
Opener Kennan Ward/Corbis; 1 BIOS Klein J.-L. & Hubert M.-L./Peter Arnold, Inc.; 4 BIOS Klein J.-L. & Hubert M.-L./Peter Arnold, Inc.; 6 Norbert Rosing/National Geographic Stock/National Geographic Image Collection; 7 Ed Reschke/Peter Arnold, Inc.; 8 ©Leo Keeler/Animals Animals/Earth Scenes; 9 Courtesy of the University of Wisconsin/Madison Archives/University of Wisconsin Digital Collections Center; 10 Jupiter Images; 12 William F. Campbell//Time Life Pictures/Getty Images; 13 William Campbell/Corbis; 15 (T) Barry O’Neil/National Park Service/Time Life Pictures/Getty Images, (B) The Billings Gazette, National Park Service, File/©AP Images; 16 Norbert Rosing/Getty Images; 17 Map Resources; 18 Dan Hartman/NHPA/Photoshot; 20 (Inset) Alamy Images, (Bkgd) Chris Boswell/Alamy Images.
ISBN 13: 978-0-328-52542-3 ISBN 10: 0-328-52542-1
Copyright © by Pearson Education, Inc., or its affiliates. All rights reserved. Printed in the United States of America. This publication is protected by copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permissions, write to Pearson Curriculum Rights & Permissions, One Lake Street, Upper Saddle River, New Jersey 07458.
Pearson® is a trademark, in the U.S. and/or in other countries, of Pearson plc or its affiliates. Scott Foresman® is a trademark, in the U.S. and/or in other countries, of Pearson Education, Inc., or its affiliates.
1 2 3 4 5 6 7 8 9 10 V0G1 13 12 11 10 09 3
Wolves and Humans For thousands of years, humans have had a deep-
seated fear of wolves. They regard them as dangerous creatures that threaten the lives of both people and other animals. As far back as 7,000 years ago, farmers were killing wolves in order to protect their sheep and cattle. Even today, many children are raised with stories that warn against the “big bad wolf.”
Scientists estimate that about 250,000 wolves roamed free in North America when Europeans arrived in the 1600s. The wolves’ freedom, however, did not last long. Many settlers became farmers, and they feared the animals would kill their sheep, cattle, and other livestock. The truth, however, was that wolves only looked to attack livestock after the disappearance of their own prey.
When settlers began building their farms, they cut down large areas of forest to create space for their crop fields. With the loss of trees, many of the animals that wolves normally preyed upon lost their habitats. Since these animals no longer had a place to live and little or nothing to eat, they soon left, leaving the wolves with nothing for food but the farmers’ livestock.
People across North America began to eliminate the wolves through hunting, trapping, and poisoning. By the late 1800s, wolves had all but disappeared in most parts of the United States. In the west, hunting was especially heavy around Yellowstone National Park. By 1926 not a single wolf was to be found in the entire the park.
Yellowstone National Park Yellowstone National Park is a vast area of land
that stretches over two million acres. Most of the park is in northwest Wyoming, but parts of it spill over into Idaho and Montana. In order to preserve the beauty of Yellowstone, the U.S. government declared the area to be a national park in 1872. It became the first national park in the world.
Yellowstone is famous for its natural wonders, such as hot springs, lakes, canyons, geysers, and waterfalls. Its forests contain beautiful trees and plants. The park is also home to many kinds of animals, including bear, elk, deer, and bison.
Today it is against the law to hunt in any national park. In 1872, however, visitors to Yellowstone were given permission to hunt. They killed predators in the park that threatened the safety of the elk, deer, and other animals there. They hunted one predator in particular—the wolf. In fact, at one time, hunters were actually paid to kill wolves inside the park in order to protect the other animals.
Hunters thought they were doing the park a favor by wiping out the wolves of Yellowstone. The wolves were at the top of the food chain, eating any animal weaker than themselves to survive. They were rarely attacked themselves because of their strength and hunting prowess. The wolves preyed on herbivores, such as elk and deer, that merely ate plants and caused no harm—or so it seemed. Therefore, how could the hunting and killing of wolves be a bad thing?
The absence of wolves, however, had an effect that no one at the time predicted. Without the top predators around, the elk and deer in the park experienced a dramatic increase in their population. Soon, Yellowstone had more plant-eating animals than its vegetation could support. The herbivores had to compete for food.
Yellowstone National Park is famous for its natural beauty.
The absence of wolves at Yellowstone had another negative effect. A new predator—the coyote—rose to the top of the food chain. Rather than deer and elk, most coyotes in the park preyed on ground squirrels and other small rodents. With the increase in coyotes, smaller predators, such as foxes and owls, began to find difficulty in catching enough food to eat. Some of the foxes and owls began to starve and eventually grew sick or died.
Some coyotes at Yellowstone also preyed on larger animals, such as fawns, or baby deer. In a short span of time, the coyotes killed so many fawns that park officials worried about the future of the entire deer population in the park.
With no wolves at Yellowstone, coyotes rose to the top of the food chain.
The absence of wolves at Yellowstone did not affect only the food chains of larger animals. It also had an impact on the park’s vegetation. This, in turn, had far-reaching effects on numerous other ecosystems throughout the park.
For example, the overpopulation of elk relentlessly gnawed on the bark and shoots of aspen trees, cottonwood trees, and willow bushes. As a result, new tree and bush growth came to a rather abrupt halt. This affected animals that relied on the trees and bushes that served as their habitats. For instance, songbirds had fewer places to nest, causing many of them to disappear from the area altogether.
Without wolves to chase them, more elk had time to feast on the trees and bushes, many of which stopped growing.
With the halt of new tree and bush growth, beavers in the park also suffered. They fed on aspen trees and stored its wood for their food supply during the winters. Throughout the year, they also used the trees to construct homes and dams. Their dams created ponds that became homes for other park creatures, including ducks, moose, and dragonflies, as well as general pond life such as fish, frogs, and algae. But with fewer trees, many beavers and other park creatures went hungry and became homeless or died.
A New View of Wolves It took scientists many years to come to the
realization that the absence of wolves at Yellowstone was hurting the animals and plants that remained there. One of the first scientists to discover the problem was Aldo Leopold. He began his career as a forest ranger in the southwestern part of the United States, and during his first years on the job, he thought—like everybody else—that killing wolves was good for the environment.
Wolves usually attack only sick and old animals, and leave the strong, healthy ones alone.
Later, however, Leopold changed his mind about and attitude towards the dreaded predators. He knew that other scientists had been studying wolves around the country. Those scientists concluded that wolves were a valuable part of their ecosystems. They claimed that the wolves, rather than causing harm, were actually helping their environments by preying on other animals.
How could wolves help by killing other animals? The answer was simple and logical. Scientists found that wolves mostly preyed on old and s