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s m i t h s o n i a n Smithsonian First American Edition, 2015 Published in the United States by DK Publishing 345 Hudson Street, New York, New York 10014 Established in 1846, the Smithsonian—the world’s largest museum and research complex—includes 19 museums and galleries and the National Zoological Park. The total number of artifacts, works of art, and specimens in the Smithsonian’s collections is estimated at 138 million, the bulk of which is contained in the National Museum of Natural History, which holds more than 126 million specimens and objects. The Smithsonian is a renowned research center, dedicated to public education, national service, and scholarship in the arts, sciences, and history. Copyright © 2015 Dorling Kindersley Limited DK, a Penguin Random House Company 15 16 17 18 19 10 9 8 7 6 5 4 3 2 1 001–259136–October/2015 All rights reserved. Without limiting the rights under the copyright reserved above, no part of this publication may be reproduced, stored in or introduced into a retrieval system, or transmitted, in any form, or by any means (electronic, mechanical, photocopying, recording, or otherwise), without the prior written permission of the copyright owner. Published in Great Britain by Dorling Kindersley Limited. A catalog record for this book is available from the Library of Congress ISBN 978-1-4654-3804-1 DK books are available at special discounts when purchased in bulk for sales promotions, premiums, fund-raising, or educational use. For details, contact: DK Publishing Special Markets, 345 Hudson Street, New York, New York 10014 SpecialSales@dk.com Printed in China A WORLD OF IDEAS: SEE ALL THERE IS TO KNOW www.dk.com Consultants MAMMALS Professor David Macdonald CBE is a leading world authority on mammals, and is founder and Director of the Wildlife Conservation Research Unit at Oxford University, UK. Aside from his many scientiﬁc publications, he is known for his prize-winning books and ﬁlms, such as Meerkats United. BIRDS David Burnie studied Zoology at Bristol Uni; versity, UK, and has contributed to nearly 150 books on animals and the environment. He is a Fellow of the Zoological Society of London. REPTILES Dr. Colin McCarthy is a scientiﬁc associate of the Life Sciences Department, and formerly Collection Manager of Reptiles, Amphibians, and Fish, at the Natural History Museum, London, UK. AMPHIBIANS Professor Tim Halliday retired as Professor of Biology at the Open University in 2009 but continues to pursue his interest in the reproductive biology of amphibians. INVERTEBRATES Dr. George C. McGavin is a zoologist, author, explorer, and television host. He is an Honorary Research Associate of the Oxford University Museum of Natural History and a Research Associate of the Department of Zoology at Oxford University, UK. His TV credits include Expedition Borneo, Lost Land of the Jaguar, Lost Land of the Tiger, and Monkey Planet. GENERAL CONSULTANT Dr. Kim Dennis-Bryan is a paleontologist who worked at the Natural History Museum, London, before becoming an associate lecturer in life and environmental sciences at the Open University, UK. EDITORIAL CONSULTANT Dr. Don E. Wilson is Curator Emeritus, Vertebrate Zoology, National Museum of Natural History, Smithsonian. He is the author of more than 250 scientiﬁc publications and 25 books on a variety of topics, including the mammals of North America, bats, humans, biodiversity, and mammal species of the world. He is an elected Fellow of the AAAS, and Honorary member of ASM. Contributors Jamie Ambrose is a UK-based American author, editor, and journalist with a special interest in the natural world. Richard Beatty (glossary writer) is a writer and editor based in Edinburgh, UK. Dr. Amy-Jane Beer is a biologist, nature writer, and editor of the UK charity PTES (People’s Trust for Endangered Species) Wildlife World magazine. Derek Harvey is a naturalist with particular interests in evolutionary biology, and writer for titles that include DK’s Science and The Natural History Book. Ben Hoare is features editor of BBC Wildlife magazine, UK. Rob Hume is a natural history writer and editor with a lifetime interest in wildlife, especially birds. He is author of more than 20 books, including DK’s Bird, and Birds of Europe and North America. Tom Jackson is a zoologist and science writer based in Bristol, UK. Steve Parker has a zoology degree and has written more than 200 books and websites on nature, ecology, conservation, and evolution. Dr. Katie Parsons has a PhD in animal behavior and ecology. She is currently a freelance natural history writer and conservation consultant. John Woodward has written more than 40 books and many hundreds of articles on all aspects of the natural world. DK LONDON Senior Art Editor Ina Stradins Senior Editors Janet Mohun, Peter Frances Project Editor Gill Pitts US Editor Jenny Siklos Project Art Editor Francis Wong Designer Simon Murrell Editorial Assistant Frankie Piscitelli Indexer Hilary Bird Picture Researcher Liz Moore New Photography Gary Ombler Cartography Simon Mumford, Ed Merritt Jacket Designer Mark Cavanagh Jacket Editor Claire Gell Jacket Design Development Manager Sophia MTT Pre-production Producer Francesca Wardell Producer Rita Sinha Managing Art Editor Michael Duffy Managing Editor Angeles Gavira Art Director Karen Self Design Director Phil Ormerod Publisher Liz Wheeler Publishing Director Jonathan Metcalf DK INDIA Senior Art Editor Mahua Mandal Senior Editor Vineetha Mokkil Project Editor Dharini Ganesh Art Editors Divya P R, Anjali Sachar Editor Susmita Dey Managing Art Editor Sudakshina Basu Managing Editor Rohan Sinha Picture Researchers Deepak Negi, Surya Sankash Sarangi Jacket Designer Suhita Dharamjit Managing Jackets Editor Saloni Singh Production Manager Pankaj Sharma Pre-production Manager Balwant Singh Senior DTP Designers Harish Aggarwal, Vishal Bhatia DTP Designer Vijay Kandwal SMITHSONIAN ENTERPRISES President Christopher A. Liedel Senior Vice President, Consumer and Education Products Carol LeBlanc Vice President, Consumer and Education Products Brigid Ferraro Licensing Manager Ellen Nanney Product Development Manager Kealy Gordon DATA PANELS Summary information is given at the start of each proﬁle. Measurements are for adults of the species and may be a typical range, single-ﬁgure average, or maximum, depending on available records. LENGTH (all groups) MAMMALS Head and body excluding tail. For dolphins, whales, seals, sea lions, manatees, and dugongs it includes the tail. BIRDS Tip of bill to tip of tail (except penguins, ostrich, rhea, and emu, which indicates height from feet to head). REPTILES Tip of snout to tip of tail (except tortoises and turtles where it is the length of the upper shell). FISH AND AMPHIBIANS Head and body, including tail. INSECTS Body length; wingspan for butterﬂies and moths. HABITAT SYMBOLS Rivers, streams, and all ﬂowing water Temperate and deciduous forest, open woodland Evergreen, coniferous, and boreal forest and woodland Mangrove swamps, above or below the waterline Tropical forest and rainforest, dry forest of Madagascar Coastal areas including beaches and cliffs, areas just above high tide, in the intertidal zone, and in shallow, offshore waters WEIGHT (Mammals, birds, reptiles, amphibians, and ﬁsh only) Body weight. Mountains, highlands, scree slopes, any habitat considered alpine or subalpine conditions DIET All diet listed by commas (except caterpillars’ diet; butterﬂies’ diet, separated by a semicolon). Desert and semi-desert BREEDING SEASON (Amphibians only) The time of year in which breeding occurs. STATUS (all groups) Wildlife of the World uses the IUCN Red List (see p459) and other threat categories, as follows: Critically endangered (IUCN) Facing an extremely high risk of extinction in the wild in the immediate future. Endangered (IUCN) Facing a very high risk of extinction in the wild in the near future. Vulnerable (IUCN) Facing a high risk of extinction in the wild in the medium-term future. Near threatened (IUCN) Strong possibility of becoming endangered in the near future. Common/Locally common (IUCN: Least concern) Low-risk category that includes widespread and common species. Not known (IUCN: Data deﬁcient, Not evaluated) Not a threat category. Population and distribution data is insufﬁcient for assessment. Data not yet assessed against IUCN criteria. Seas and oceans Coral reefs and waters immediately around them Polar regions, including tundra and icebergs Open habitats including grassland, moor, heath, savanna, ﬁelds, and scrub Urban areas, including buildings, parks, and gardens Wetlands and all still bodies of water, including lakes, ponds, pools, marshes, bogs, and swamps LOCATION MAP Shows distribution of species in the wild CONTENTS CENTRAL AND SOUTH AMERICA 74 ANIMAL HABITATS 10 NORTH AMERICA 20 12 FORESTS 22 PEAKS AND PRAIRIES 14 GRASSLANDS 24 CANADIAN ARCTIC 76 LAND OF THE JAGUAR 16 EXTREME ENVIRONMENTS 34 YELLOWSTONE 78 COSTA RICAN RAINFOREST 18 AQUATIC ENVIRONMENTS 44 CENTRAL GREAT PLAINS 84 ANDEAN YUNGAS 52 SIERRA NEVADA 90 AMAZON RAINFOREST 60 MOJAVE DESERT 100 THE PANTANAL 66 FLORIDA EVERGLADES 108 ANDEAN ALTIPLANO 114 ARGENTINE PAMPAS 122 GALAPAGOS ISLANDS EUROPE 130 132 PLAINS AND PENINSULAS 134 NORWEGIAN FJORDS 140 SCOTTISH HIGHLANDS 146 THE CAMARGUE 152 TAGUS VALLEY 158 THE ALPS 164 BAVARIAN FOREST AFRICA 174 ASIA 244 AUSTRALASIA ANTARCTICA 310 360 176 A SUNBAKED LAND 246 LAND OF EXTREMES 312 THE RED CONTINENT 362 LAND OF ICE AND SNOW 178 ETHIOPIAN HIGHLANDS 248 ARABIAN HIGHLANDS 364 SOUTHERN OCEAN ISLANDS 184 GREAT RIFT VALLEY LAKES 254 TERAI-DUAR SAVANNAS 314 NEW GUINEA MONTANE FOREST 192 SERENGETI SAVANNAS 266 EASTERN HIMALAYAS 208 CONGO BASIN 272 UPPER YANGTZE FORESTS 218 OKAVANGO DELTA 278 GOBI DESERT 228 KALAHARI DESERT 284 NIHONKAI MONTANE FOREST 236 MADAGASCAN DRY FORESTS 292 BORNEAN RAINFOREST 302 SULU-SULAWESI SEAS 320 NORTH AUSTRALIA SAVANNAS 328 GREAT SANDY-TANAMI DESERT 370 ANTARCTIC PENINSULA 376 THE ANIMAL KINGDOM 456 GLOSSARY 334 EAST AUSTRALIAN FORESTS 460 INDEX 344 GREAT BARRIER REEF 478 ACKNOWLEDGMENTS 354 NEW ZEALAND MIXED FOREST FOREWORD We share the world with an extraordinary diversity of wildlife, the breadth and depth of which is, frankly, wonderful. As our ancestors traveled through the continents of planet Earth, they encountered amazing animals in each new area they explored. This “biogeography”—or how species are geographically distributed throughout different natural habitats—is something you can now experience for yourself in the following pages, by discovering which animals inhabit each continent’s ecosystems. It is the aim of this book to present a visually compelling exploration of the world’s ecoregions by summarizing the creatures that live there, as well as providing key facts about their life cycles and biology. More than 40 ecoregions are described in depth, and all are complemented by a spectacular view of the animals—both the familiar and the less well-known—that inhabit them. By grouping species together within their natural habitats, it becomes easy to spot the top predators in each one, as well as the variety of creatures that live alongside them. Combining this global view with the very best the world of wildlife photography has to offer allows us to take you on a journey that can be completed in a variety of ways, but always at your own pace, and in the comfort of your home. Most people are familiar with the animals, large and small, that share the regions in which we live. The current age of easy worldwide travel has allowed some of us to experience more exotic parts of the globe, where the animals are unfamiliar, different, and sometimes very strange indeed. Yet this diversity of habitats and organisms is, sadly, diminishing as the world becomes ever more populated with humans, and the impact of those increasing populations takes a heavy toll on natural areas worldwide. The more we can learn about the diversity of wildlife on our planet, the easier and more effective it will be to design and implement conservation programs that ensure we retain species for future generations. As you make your way through this stunning compilation of our planet’s amazing animals, enjoy the wonder and spectacle of life on Earth and take a moment to realize just how lucky we are to be a part of it—in our own time and place. DON E. WILSON SMITHSONIAN INSTITUTE, WASHINGTON, D.C. 1 0 | ANIMAL H ABITATS ANIMAL HABITATS Two-thirds of Earth’s surface is covered by oceans. It is this abundance of water that enables the planet to support billions of living organisms, both in the seas and on the continents and islands that make up the land. The environment in which an organism lives is its habitat, and the huge range of habitats found on land are home to a vast number of plant species and a spectacular diversity of animals. Geographers divide the world into ecoregions characterized by broad habitat types such as forest, grassland, wetland, desert, or polar zones. These can in turn be subdivided almost endlessly into more precise habitats, each supporting a unique community of plant and animals. Climate exerts a powerful inﬂuence over each of the world’s great ecoregions. Energy input CO N T I N E N T from the Sun is greatest at the tropics, and the transfer of this energy via the atmosphere and In southern Europe, oceans generates the currents of air and water the warm waters of the Mediterranean lap the coast and much that drive the world’s weather systems. of the land is covered by Mediterranean On land, weathering of rock leads to the woodland and scrub. The soaring formation of soil in which plants grow, mountains of the Alps form a physical forming the basis of ecological communities. barrier, beyond which lies the ECO R EG I O N The Alps comprise one of the world’s best-known montane ecoregions. They extend into eight European countries, forming a snow-tipped arc that stretches from France and Italy in the southwest to Austria in the east. colder, wetter north. Variety of life Biodiversity refers to the variety of life in a given habitat or ecoregion. As a rule, biodiversity increases toward the equator, with tropical forests and warm coastal seas registering the greatest numbers of species. Both poles are inhabited by comparatively few animal species, but in the Arctic, many animals live on land whereas in Antarctica, most animal life is found in the ocean. Plants and animals become better adapted to their particular habitat through natural selection—those most suited to the environmental conditions survive in greater numbers and produce more offspring. This is a continuous process as habitats change slowly over time. Sudden events such as volcanic eruptions, ﬂoods, or human development can have catastrophic impacts, especially on species that are specialized to a certain way of life. So-called generalist species cope better with change, such as a fall or rise in temperature, but may be displaced by specialist species when conditions stabilize. Scientists estimate that only 14 percent of species have been identified so far, and of those, 91 percent live on land THE ALPS ECOREGION If you pick any place on the planet, you will ﬁnd a unique set of conditions, inﬂuenced by geography, latitude, and climate. This means the area, such as the Alps, will be home to a unique community of plants and animals. ANIMAL HABITATS H A B I TAT S | 11 FO O D C H A I N S The habitats of the Alps are found elsewhere in the world, but here their characteristics are contrasted by large differences in altitude. The grasses and herbs found in a high alpine meadow, for example, are very different from those in a lowland grassland. One way all the plants and animals in a habitat interact is via a food chain. Plants convert the Sun’s energy into food for growth and reproduction, and are eaten by herbivorous animals. These in turn become food for predatory or scavenging animals. M O U N TA I N S A N D SCREE SLOPES Mountains are effectively inland islands, where unique species can live and evolve in isolation. Slope habitats are heavily inﬂuenced by latitude, altitude, incline, aspect, and the underlying rock. Conditions above the tree line (beyond which no trees grow) are harsh. E AG L E O W L The Eurasian eagle owl is the top predatory bird in the Alps. It hunts mainly small mammals, but will also target other birds of prey. M O N TA N E FOREST Forests on mountains are banded according to altitude, with broadleaf trees dominating the warmer, lower slopes, and conifers thriving on higher ground up to the tree line. Because sloping, rocky ground is difﬁcult to farm, mountainsides often retain more tree cover than ﬂatter ground. MARMOT Alpine marmots spend the summer months feeding on lush grasses and herbs, building up fat to help them survive the long alpine winter. ALPINE MEADOW Where ﬂooding or unstable ground prevent trees encroaching, grasses and herbs ﬂourish in spectacular diversity. At high-altitude, there is a sudden burst of growth in spring and summer and the meadows are ﬁlled with blooms—an important food source for many animals. DA N D E L I O N As well as providing food for marmots, alpine dandelions are a welcome source of nectar for butterﬂies and bees. 12 | ANIMAL HABITATS FORESTS The lungs of our planet Roughly one-third of the world’s land area is covered with trees. Some are the largest and longest-living organisms on Earth. Their roots, trunks, branches, and leaves form an uncountable variety of microhabitats, the character of which varies according to location. Dead and decaying leaves and wood also form a vital component of forest ecosystems, providing habitat and food, and releasing nutrients back into forest soils. Clearings left by fallen trees throng with light-loving ground plants and insects until new trees close the gap. breaking them. By keeping their dark green leaves all year, they can make food whenever the Sun shines. The resin-ﬁlled leaves are distasteful to all but a few insects and so are not eaten even when food is scarce. Farther south, winters are still cold, but summers are longer and warmer. Forests here are generally deciduous. The trees have broad leaves and spreading branches that maximize their ability to harvest light and get Boreal and temperate forests The wide range of climates in temperate areas supports coniferous, deciduous, broadleaf evergreen, and mixed forest. In the far northern boreal forests, winters are longer, temperatures lower, and snow fall more frequent—conditions to which coniferous trees are well adapted. Their triangular shape and narrow leaves prevent excess snow settling on their branches and T E M P E R AT E B R OA D L E A F T E M P E R AT E CO N I F E R O U S Nonﬂowering plants, such as conifers, produce their seeds in cones, which are released when dry conditions cause the cones to open. The tiny seeds of western hemlock are eaten by chickadees, pine siskins, and deer mice. BOREAL The hardy, evergreen conifers found in northern boreal forests provide less food than other trees due to the harsh climate and short growing season. In winter, when food is scarce, many animals migrate to warmer areas or hibernate. SEYCHELLES ▷ Tropical rainforest on Silhouette Island, Seychelles, in the Indian Ocean. The seasonal availability of some foods presents a challenge to woodland animals. Some, such as grey squirrels, solve the problem by hoarding nuts and seeds in tree holes and underground caches, to which they return in winter. FORESTS energy from the Sun. However, such leaves also pose a risk in strong winds and heavy snow, so temperate broadleaf trees tend to produce thin leaves that are shed in the fall. The trees remain in an almost dormant state all winter and produce new leaves the following spring. In the most southerly temperate areas, summers are long, hot, and dry, and winters are warm and wet. The broadleaf evergreen forest that grows in these climates ranges from the tall eucalypts of Australia to the shorter, more open woodland of parts of California and the Mediterranean. Tropical forests At the equator, the climate is warm and moist all year round, providing ideal conditions for plant growth and creating the most diverse of all terrestrial habitats. Trees and other forest plants grow in profusion forming vast rainforests, cloud forests, and montane forests that are green all year round. In the northern tropics, the forests of Southeast Asia are inﬂuenced by heavy monsoon rains, giving | 13 FOREST DISTRIBUTION Coniferous forests are generally found at higher latitudes and altitudes than temperate forests, and the boreal forest belt extends to the edge of the Arctic tundra. Tropical forests need warmth year-round and are centered on the equator. Boreal forest Temperate forest Tropical forest the region distinct wet and dry seasons. During the rains the forest is lush and green but in the dry season, many trees shed their leaves, allowing the sunlight to penetrate to the forest ﬂoor. In areas where there is a long dry season, such as Madagascar and the Caribbean, tropical and subtropical dry forests are found. Composed mainly of broadleaved trees that shed their leaves to conserve water during dry spells, these forests are less diverse than other tropical forests. However, they are still home to a diverse community of animals adapted to cope with the demands of living in a hot, dry climate. MEDITERRANEAN Broadleaf evergreen forest is also known as Mediterranean forest, and typical trees include cork oaks, some species of pine, and eucalypts. Cork oaks are a particularly important habitat, providing food, shelter, and nesting sites for many species of animal. T R O P I C A L D RY Trees in tropical dry forests survive the long dry season by shedding their leaves, having thick bark, and deep roots that access groundwater. Many species have thorns or spines as a deterrent to animals that might try to feed on them. TROPICAL MOIST The dense canopy of the broadleaf trees growing in most tropical forests holds most of the forest’s food. This means that many animals are adapted to life in the trees and are rarely seen at ground level. They include scarlet macaws and spider monkeys. 14 | ANIMAL HABITATS GRASSLANDS Little shelter, but plenty of food Where the climate is too dry to support trees, but wet enough for plants to grow, grasses and low-growing herbs dominate the landscape. These plants are highly diverse, and grassland habitats range from the high alpine meadows of Europe to tree-studded African savanna, tall grass prairies of North America, windswept Asian steppes, seas of head-height grass in India, China, and South America, and the dry desert scrublands of Australia. Today, they account for about 40 percent of the land area. Temperate grasslands The relatively ﬂat terrain and scarcity of trees in temperate grassland gives rise to vast expanses of fairly uniform landscape across which strong winds can blow unimpeded. There are fewer habitats than in forests and, as a result, there are fewer animal species in temperate grassland, too. Grass is, however, able to support vast numbers of herbivores because, unusually in plants, its growth point is below ground level. As it is untouched by the animals that graze on it, grass regrows quickly after it has been cropped. This adaptation also allows grass to survive long periods without rain that kill many other plants. In the past, grassland covered large tracts of the temperate world, but with the advent of agriculture, much of it has been used for growing crops—often with unforeseen consequences. Grass is unusual in that it channels most of its energy into growing roots rather than leaves. This allows grass to get the water and nutrients it needs and has T E M P E R AT E GRASSLAND Although grasses predominate, many herbaceous plants also grow in temperate grassland. Bright ﬂowers attract insects, which in turn attract insect-eating birds. The grassland also provides food for mammals of all sizes, from bison to hares. M O N TA N E GRASSLAND These high-altitude grasslands occur at all latitudes. The plants and animals that live in these regions must be able to endure low temperatures, intense sunlight, and potentially harmful ultraviolet radiation. They include the guanaco of South America. CUSTER STATE PARK ▷ The prairie habitat in South Dakota, provides a natural refuge for a herd of American bison. GRASSLANDS the side-effect of stabilizing the soil it is growing in. When land such as this is plowed and the grass removed, the soil rapidly deteriorates and is blown away as dust, leaving only bare earth in its place. | 15 GRASSLAND DISTRIBUTION Tropical grasslands Scattered trees and scrub are a feature of tropical savannas, making them more diverse than their temperate counterparts. However, they cannot encroach far because, unlike grass, trees and scrub cannot survive the frequent ﬁres that occur during the dry season. Although these ﬁres appear destructive, the ash created provides soil nutrients that fuel the growth of fresh grass during the wet season that follows. While some tropical grasses, such as bamboo and elephant grass, grow very tall, most savanna grassland provides little cover, making it difﬁcult for both predators and prey to hide. Predators rely on stealth, speed, and sometimes cooperation to catch their food, whereas prey animals rely on spotting hunters before they The largest temperate grasslands are the prairies of North America and the Asian steppes, which stretch from the far east of Europe to northern China. Tropical grasslands include those of sub-Saharan Africa and Brazil. Temperate grasslands Tropical grasslands get too close and running away. They do this by living in groups, which offers safety in numbers, and by relying on their senses. Prey animals have eyes on the sides of their heads for good all around vision, large swiveling ears, and an excellent sense of smell—hares are a good example. SCRUB In areas with long dry summers such as California and the Mediterranean, there is a transition zone between woods and grassland that is dominated by low, woody shrub vegetation. Also called heathland and chaparral, scrub offers more cover for animals. TROPICAL GRASSLAND These are usually warm year-round, with a long dry season followed by a short wet season that sees a spurt of plant growth. African savanna elephants help to maintain their habitat by eating woody shrubs and knocking down trees to feed on their leaves. WETLANDS Areas of land that are routinely inundated by fresh or salt water are often dominated by grasses, reeds, and sedges, while water hyacinths form free-ﬂoating mats of vegetation. Wetlands support many species, particularly birds. 16 | ANIMAL HABITATS EXTREME ENVIRONMENTS Survival against the odds Polar areas and deserts are some of the least hospitable habitats on Earth. The lack of rain and extreme temperatures create difﬁcult conditions for life, and the few humans that live there lead a seminomadic existence. Today, several of these fragile, untouched ecoregions are under threat because of the discovery of oil, gas, and other minerals. Polar regions Much of the Arctic and Antarctica is effectively a desert gripped by ice. Winters are long and permanently dark and summers are short but, because the Sun never sets, there is a continual source of energy for plant growth. Where rock is exposed, the soil is virtually nonexistent, and usually at freezing point or below. Trees cannot survive here, and vegetation is limited to mosses, lichens, fungi, and a handful of ﬂowering plants. This open, rather featureless landscape, called tundra, is found between 60-80 degrees north and south of the equator. It is far more extensive in the northern hemisphere, covering large tracts of northern Canada and Russia. Similar areas on mountains above the tree line are called alpine tundra. Polar regions may support a number of large land animals, but most are reliant on the sea for their food. This is because despite the icy conditions, sea life is plentiful. The cold waters of the Arctic and Southern oceans are rich in oxygen and the seabed provides ALPINE TUNDRA ARCTIC TUNDRA The Arctic poppy is one of the few ﬂowering plants found on the Arctic tundra. The short growing season means the plant must grow, ﬂower, and produce its seeds rapidly. It is usually pollinated by ﬂies, but can self-pollinate if necessary. POLAR Polar regions may seem inhospitable, but their icy waters support several specialist mammal species, including walruses and seals. Small ice ﬂoes and broken pack ice are ideal habitat for bearded seals, for example, as they need easy access to the water to feed. ANTARCTICA ▷ Snow covers the tundra on the northeast tip of the Antarctic Peninsula in winter. Found at altitudes of around 10,000 ft (3,000 m) with snow above and boreal forest below, alpine tundra is cold and windy and has sparse vegetation. Golden eagles hunt there during the summer as the open ground provides little cover for their prey. EXTREME ENVIRONMENTS plentiful nutrients. In summer, these oceans provide rich pickings for the many marine mammals and seabirds that migrate to these areas to feed and breed. The tundra also has summer visitors, such as reindeer that spend the winter sheltering from the cold in the taiga forest to the south, but return each summer. Desert regions Most of the world’s great hot deserts, such as Africa’s Sahara, are found in the subtropics, where dry conditions persist for months at a time. Others, such as the Mojave in the US southwest, are found on the dry leeward side of mountains. A few, such as the Atacama Desert in South America, are coastal and lack rain due to cold offshore water inhibiting cloud formation. Cold deserts are found in continental interiors and are very hot in summer and very cold in winter. All of these deserts are dry, receiving less than 6 in (15 cm) rain annually, and most are cloudless. The exception is coastal | 17 DESERT AND POLAR ICE DISTRIBUTION Deserts in the southern hemisphere tend to be less extensive than those in the north, which include the largest desert of all: the Sahara. Almost all of Antarctica and most of Greenland in the Arctic Circle is covered in ice-sheets. Desert Ice desert, which can beneﬁt from early morning fog drifting in from the ocean. Hot deserts, although hot all year, are cold at night as the lack of cloud cover allows heat to escape freely. Cold deserts also have large daily temperature ﬂuctuations, but in winter, temperatures are below freezing and snow is not uncommon. Plants growing in deserts must cope not only with lack of water and extreme temperatures, but also with soils that have little organic matter and few soil microorganisms. All desert plants and animals tend to restrict their reproductive efforts to periods of rainfall and show a range of adaptations to heat, such as being able to retain or store water, and many animals forage at night. CO L D DESERT Despite the hostile treeless environment, limited rainfall, and enormous seasonal temperature differences, cold deserts are home to a variety of animals. Small mammals include the dwarf hamster, large ones the critically endangered Gobi bear. COA S TA L DESERT In the early morning, coastal deserts beneﬁt from moisture carried inland as fog. It is an important source of water for a number of arthropods and reptiles, some of which have adaptations to enhance water collection and storage. H OT DESERT Daytime temperatures in hot deserts are so high that even “cold blooded” arthropods, which are reliant on the Sun for warmth, seek shade to avoid the heat. Many animals, such as the deathstalker scorpion, avoid the Sun completely by being nocturnal. 18 | ANIMAL H ABITATS AQUATIC ENVIRONMENTS Planet Earth is really planet Ocean More than 70 percent of the Earth’s surface is covered by water, which in its liquid form is essential for life. Water is continually circulating around the planet, evaporating from its surface and being carried as water vapor in the atmosphere until it falls again as rain. Around 95 percent of the Earth’s water is salt water, which is found in seas, oceans, and coastal lagoons as well a few isolated soda and salt lakes. The other 5 percent is fresh water, which is seen in rivers and lakes, but also includes the ice held in polar regions and glaciers, and groundwater that is hidden from view. The challenges of life in fresh and salt water are very different and relatively few animal species are able to move from one to the other. ranging from fast-ﬂowing rivers and swampy wetlands to the relatively calmer but deeper water of many lakes. Organisms living in lakes and rivers must cope with strong currents, survive freezing conditions in winter, and endure summer droughts when some rivers and Rivers and lakes Fresh water is vital for life on land— without water, plants cannot grow and animals would have nothing to drink. Rivers and lakes create diverse habitats M A N G R OV E S LAKES Lakes are often isolated, with little opportunity for new aquatic species to colonize them (unless introduced by humans). As a result they may have large numbers of endemic species or subspecies that have evolved to exploit the available habitats. RIVERS The steeper the gradient of a river, the faster the water ﬂows and the stronger the current. More animal species tend to be found downstream, where slower-ﬂowing water allows aquatic plants to grow. This increases the number of habitats. CALIFORNIA COAST ▷ The sheer power of a breaking wave in Monterey Bay, CA, is revealed. These wetlands provide safe inshore nurseries for various marine animals as well as breeding sites and roosts for many bird species, including the scarlet ibis. These wading birds use their long, curved, sensitive bills to locate food in the soft mud. AQUATIC ENVIRONMENTS shallow lakes disappear. Plants, including tree species, tend to grow where water ﬂow is slow along stream and river banks or on islands in river channels. However, plants, such as water hyacinth, can cover large areas of fresh water. Animals may be conﬁned to water—ﬁsh, for example—while others spend only part of their life there, including frogs, hippopotamuses, and dragonﬂies. Each species occupies a particular habitat, and together they create a distinct community unique to that particular river or lake. Mangroves Restricted to tropical and subtropical regions, mangrove swamps usually develop in intertidal areas on muddy shores, although some extend for some distance inland. Only mangrove trees can grow successfully in the waterlogged, salty mud and survive regular inundation by seawater. The different species have various adaptations that allow them to do this, including | 19 having prop roots for additional support in soft sediment, and the ability to ﬁlter out salt as it enters their roots, or to store it in their leaves and lose it when the leaves are shed. Mangrove swamp is the most endangered of the world’s habitats due to large scale removal in recent years to make way for aquatic farming of ﬁsh, crustaceans, and mollusks. Oceans and seas Although the world’s oceans are interconnected, numerous seas, each with their own distinct characteristics, exist within them. The sunlit upper waters of the ocean have the most organisms, and coral reefs are among the most biodiverse. However, ecoregions also exist much deeper, with food chains based on organic material drifting down from above or on bacteria able to manufacture food using chemical reactions that do not need sunlight. Coastal regions are extremely harsh environments for wildlife as rocks and sandy shores are periodically exposed to the air, and buffeting by waves can damage and dislodge organisms unless they are ﬁrmly anchored. Oceans support a huge variety of life, ranging from microscopic algae that underpin oceanic food chains to the planet’s largest living animal, the blue whale. COA S T S Exposure to the air twice a day and buffeting by the waves are just two features of coastlines that make them the most demanding of all habitats to live in. On rocky shores, many animal species have shells for protection and to retain moisture. CO R A L R E E F S Coral reefs provide plenty of food and hiding places. This means that reef ﬁsh are usually colorful and come in a multitude of shapes and sizes as, unlike oceanic ﬁsh, they do not need to be streamlined and fast to hunt or escape from predators. OPEN OCEAN Most life in the open ocean is found at or just below the surface as this is where most of the food is produced. Despite the vast expanse of this habitat, only around 5 percent of the world’s animal species live here. British Columbia A young grizzly bear searches for salmon during a spawning run in a Canadian river. Its mother won’t be far as cubs don’t become independent until they are more than two years old. North America Al eu tia Kodiak Island Gulf of Alaska Queen Charlotte Islands Mount McKinley (Denali) 6,194m Yu kon o k s R an ge M ac ke n zi e Banks Island nt ain Victoria Island Reindeer Lake Pa r r y I slands Queen Elizabeth Islands Lake Athabasca Great Slave Lake Great Bear Lake Be a uf o rt S ea ARCTIC OCEAN Baf fin Is Baffi n Bay la nd D 2,500 98 St an ra nl d it Hudson S t r a i t is ee Péninsule d’Ungava av Gr 5,000 197 0 7,500 295 0 MM 10,000 -10 -20 -30 -4 -22 a b ra do r L a b r a d or Sea -40 0 14 -40 10 32 20 68 50 °C 30 °F 86 L M ou AVERAGE TEMPERATURE Ice Boreal forest/taiga AVERAGE RAINFALL Tundra Desert, scrub Wetland Temperate grassland Tropical, subtropical grassland Mediterranean woodland, scrub Temperate coniferous forest Temperate broadleaf forest Tropical coniferous forest Tropical dry broadleaf forest Tropical broadleaf forest IN 394 H ud son Bay a single plate, with small parts of Mexico and California lying on the neighboring Paciﬁc plate, which abuts the North American plate along the infamous San Andreas fault. The mountain ranges of the Western Cordillera have a profound inﬂuence on the climate of the west side of the continent. For example, rainshadow deserts form on the mountains’ eastern ﬂanks. Smaller, more ancient mountain ranges follow the eastern coast, while much of the interior of North America is low-lying. The vast north-south extent of the continent means it encompasses a wide range of climate types, from Arctic cold to tropical heat. Dominant ecosystems include tundra, boreal and temperate forest, prairie, desert, and extensive wetlands. These diverse habitats support an impressive range of animals, from the largest mammals—American bison and bears—to alligators living in the swamps and wetlands of the southeast. M ou PAC I F I C OCEAN n Is lands B eri n g S ea rait g St rin Be ALEUTIAN ISLANDS An arc of 69 volcanic islands, largely treeless and fogbound, that support an array of plant life and seabird colonies. Extending north from the Great Lakes to the Arctic Ocean is one of the world’s largest geologic continental shields (exposed Precambrian crystalline rocks). The rocks of the Canadian Shield have remained above sea level for almost 4 billion years. Soils form a thin layer or are absent as the rocks have been scoured by ice during repeated glaciations. CANADIAN SHIELD The world’s third largest continent is bordered by the Paciﬁc, Arctic, and Atlantic oceans, and the Caribbean Sea. Geographically, Greenland and the islands of the Caribbean are considered part of North America. Most of the continent occupies North America d e Isl an Ellesmer ECOSYSTEMS ns PEAKS AND PRAIRIES ro ack ai B M nt K E Y DATA 22 | NORTH AMERICA enzie s k y c R o mountain range continental (North American) plate Vancouver Island er Si Ma rra Gu l ra lf o if E Ma d re of O rn d cci li Ca en fo ta rn l adr GULF OF CALIFORNIA Also known as the Sea of Cortés, the Gulf of California lies between the west coast of mainland Mexico and the peninsula of Baja California. Around 800 species of ﬁsh are found in the gulf, but they are threatened by overﬁshing. aM e de Red Ri ver l err R Kansas enta Si Lago de Chapala R T Pla tte Ori d re Florida Everglades ›› p66–73 Wetland: flooded grassland, mangrove Ca de Mojave Desert ›› p60–65 Desert, scrub ja an Sierra Nevada ›› p52–59 Temperate coniferous forest Sie r oG Central Great Plains ›› p44–51 Temperate grassland M O Ri Yellowstone ›› p34–43 Temperate coniferous forest Colorado Plateau o ad or ol A N Lake Winnipeg I l Sur P l a i n s F E AT U R E D ECO R EG I O N S Sonoran Desert Grand n Canyo Great Salt Lake Snake Yellow tche wan stone S aska Lake Manitoba Ark a C H n ns a a d i a n A Lake Michigan G r e a t L a k e s Lake Superior Mississippi Delta m a ee Lake Huron e hi Lake Erie Bl l Lake Ontario Niagara Falls i S h S Str aits of The Everglades Lake Okeechobee e Fl BLUE DAMSELFISH Yu ca t a n Pen í n su l a an o Newfoundland Cape Cod ia Located in the Bahamas, the world’s deepest salt water blue hole plunges to depths of 663 ft (202 m). A blue hole is a waterﬁlled sinkhole formed by rainwater seeping into limestone bedrock. The entrance is now underwater. D E A N ’ S B LU E H O L E APPALACHIANS The oldest mountains in North America include the Great Smoky and Blue Ridge ranges. The region is largely forested and has rivers rich in ﬁsh and invertebrates. OCEAN ATLANTIC ti Caribbean Sea Gulf of Mexico s Canadian Arctic ›› p24–33 Tundra, ice ges Late spring on the lowlands of the Midwestern prairies, where there are no mountains to block air ﬂow, creates the perfect conditions for tornadoes to form. These are columns of violently rotating air that develop within storm clouds and are in contact with the ground. The most powerful tornadoes occur almost exclusively in North America. Mojave Desert Death Valley -88m Mt Whitney 4,418m Great Basin Mount St Helens 2,549m Ba TO R N A D O A L L E Y GRAND CANYON Carved by the passage of the Colorado River over 17 million years, the Grand Canyon is 277 miles (446 km) long and up to 1 mile (1.8 km) deep. subducting oceanic plate This chain of mountain ranges includes the Coastal Ranges, Rocky Mountains, and Sierra Nevada, and runs southeast from Alaska to western Mexico. Most of it formed millions of years ago as an ancient oceanic plate moved under the North American plate. This ancient plate has now almost completely disappeared. W E S T E R N CO R D I L L E R A C s oi Ill in Missi ssip pi a O d M c en wr n re Lau h Te nn es s Ala ba n t Ra A o ch Coas la a pp a ad Ri ev aN ia n Sierr ue s dg e s ain t nt u tL a M o n a i n ou Missouri da th e a t G r ri S ou Sc ot an ew No va North Saska tc PEAKS AND PRAIRIES | 23 C ia ia 24 | NORTH AMERICA CANADIAN ARCTIC I CT AR A far northern place of ice and snow 7 ar e ri ma ne ❯ al mm ma Of 3 6 ❯ n un summer sets in r e ev t gh eS h —t n Su Woo WIN df TE dorm rogs pa R FRE ss th E skin ant, e wi ZE thei froz n r e t n b lood er they so and pum lid. To s p ur of t syru a prot heir ce vive, e lls fu pm ad ctive ll con tras e by th glucose anti t, Arct e liver prev fr . ic ent eeze p cod ha In r thei r blo oteins ve th od f reez at ing. ❯ FR OG Th i s i s aL a D n d of W OO M MOTHER AND PUP ED SEAL HOOD IFE N L ed I T e t ls f AR ST sea k tha H d l i G e se d U a m TO hoo -rich incre lb er to 5–100 ur orn m wb sup o Ne on s the om 5 just f eir ble ht fr ) in at, th to a en weig 5 kg r th sea up e ir te o4 the (25 t ys. Af to th ach p nd da turn ed. E ive, a es. re fe rv ,d ers and swim it sta h t e mo mat rn to efore ea tb st l hun mu th e Melting of the permafrost releases methane and carbon, increasing the rate of global warming fur i Frozen ground On land, the top three feet of soil thaws brieﬂy in summer, but the ground beneath is permanently frozen (permafrost). Plant life is limited to mosses, lichens, and around 200 species of grass, sedge, hardy forbs, and dwarf shrubs. Land mammals able to withstand the cold include caribou, muskoxen, Arctic foxes, and lemmings. The number of invertebrate species is low, but mites and springtails become superabundant in summer, providing food for breeding migrant birds such as Arctic terns, ivory gulls, common eiders, and red phalaropes. sp LON G-D IST The AN T Arc the tic RAVE CE r th t LER the ern an a b et p wee lanet ny an travels ima as i n it l on tm are sA Ma as an rctic b igrate ny d s ree the Arc so u din A t car th to a ic anim ntarct g ib ic v a e q u o u m a o i d t h e l s h ea . ke a d ally win a t s tu n dra rduou horte er— r s reg ion trip to but s of Can the ada . ec ie s r id n The Canadian Arctic includes one of the world’s largest archipelagos—36,563 islands, most of which are uninhabited by people. The easternmost islands are mountainous, becoming lower lying in the west. For much of the long, dark winter, land and sea are bound in a vast ice-scape, broken only by rocky island peaks and occasional polynyas —areas of sea that freeze late and thaw early. Polynyas are a vital resource for marine mammals including belugas and bowhead whales, which use them as breathing holes, and for seals and polar bears, which need to access the water from the sea ice. In summer, strong tides sweep the channels between the islands. he 1 e, N ER CT | 25 CANADIAN ARCTIC LO C AT I O N ❯ BAND ED Inclu WOO L des LY BEA R one of th e wo n ca h by t o t i c I ts r m Arc le. D e c tig gh cy ars ed AN la Hi life pill d fe hey nt. Y l W O AD be he er n , t a SL TE Isa in t long cat er a ter rm for g in do ss tin S he d a r m T ree ng bea um In w lie oce upa at i d pr p th s h. b av lly h oo h in ont d an he ore lts w tc m oli t t bef adu ys. ha r a e s pea rs as da fo eez re yea ng ew fr ey 14 rgi a f Th to me nly up d e r o an e fo liv rl d’ The northernmost parts of the Canadian mainland and the islands, comprising part of the Northwest Territories and the mostly Inuit territory of Nunavut. Gr s ee n rg nd la la ICELAND es C A N A D A Edmonton Vancouver RE ❯ B i rd s c o m e t o t h e C a nad i a n Ar WINT ER W HIT Like o ther A EOUT rctic mam lan m has e als, the Ar d ctic h xcept are io which nally de t to the raps warm nse fur, a s its ran kin. In the ir close south ge in Newf hares ound of molt lan in brow n sum to a gray- d, mer c nor th oat. F ,w ur the neglig here the r th ib white le, they st aw is ay win all ye ar. ter c tic FI S Ar H O co ctic F T th mm cod HE Th e di erc are DAY be ey a ets o ially no na low re f o , bu t ﬁs bi rwh by targ the t fe hed m rds als sea ete r pre atur th urr suc , an ls, b d fr da e in th an es, w h a d fr elu om tors s eir 33 g o . wi 0 f hich guil m a as, a lem bo n ng t ( d s t 100 ive ot ve d o“ ﬂy m), to m s, or by ” u us or nd ing e er wa te r. to br ed ,b ut le av i n te r re w e fo eb D CO e TIC ARC 0 km 1000 0 miles 1000 C L I M AT E Temperatures are very low all year, only rising above 32°F (0°C) for 6–10 weeks in summer. Average annual temperatures are well below freezing, and virtually all precipitation falls as snow. (Igloolik, Nunavut) °F 86 °C 30 MM IN 60 2 1⁄4 68 20 40 1 1⁄2 50 10 20 3 32 0 0 0 ⁄4 14 -10 -4 -20 -22 -30 -40 -40 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec HA TIC ARC gos ela hip rc ta H uds o n Bay Key Average temperature Rainfall G E T T I N G WA R M E R The Arctic is warmer now than at any time in the last 40,000 years, and the extent and duration of sea ice reduces every year. In 2007, the Northwest Passage linking the Atlantic and Paciﬁc remained ice free for the ﬁrst time in recorded history. This change in conditions can have profound effects on the growth of plankton, on which all marine life ultimately depends. The sea ice is vital to polar bears, which need it for hunting and breeding. ❯ 26 | NORTH AMERICA Muskox curved horns almost meet in middle of skull Ovibos moschatus One of the few large mammals to roam the Arctic year round, the muskox is highly adapted to the cold. Its thick undercoat is covered by a coarse cloak of guard hairs over 24 in (60 cm) long, giving the animal its shaggy appearance. Its short, stocky legs and large hooves provide good traction on snow. The horns are used in defense and in dominance battles among bulls. 6—8 ft (1.9—2.3 m) 440—900 lb (200—410 kg) Locally common Sedges, grasses, leaves Musky males Muskox herds are usually mixed-sex and can have 10 to more than 100 animals, although some bulls form bachelor herds or remain solitary. Herds are smaller from July to September, when dominant bulls control breeding harems of females. The bulls give off a musky odor during the mating season, giving the animal its name. Muskox feed in lowland areas in summer, eating ﬂowers in addition to their usual diet. In winter, they move to higher ground for easier foraging. N. North America, Greenland ▷ FACING THE ENEMY When threated by predators such as wolves or a polar bear, muskoxen form a circle and face outward. Fighting bulls’ collisions can be heard up to 1 mile (1.6 km) away 4—7 ft (1.2—2.2 m) 265—660 lb (120—300 kg) Endangered Leaves, roots, bark, lichen ▽ COLOR VARIATION High Arctic subspecies, such as the Peary caribou (R. t. pearyi), are smaller and lighter colored than caribou living at lower latitudes. Both male and female caribou have antlers that they shed and regrow each year. Caribou Rangifer tarandus branching antlers N. North America, N. Europe, N. Asia outer coat of wool-like hair provides extra insulation Caribou (known as reindeer in Europe) are well adapted to life in the Arctic tundra. They have a dense coat and a broad muzzle that warms frigid air before it reaches the lungs. Caribou are strong swimmers, with broad, ﬂat hooves. These provide stability on soft summer ground and act as snowshoes in winter, becoming harder and sharper-edged—ideal for cutting through snow and ice. Despite their broad hooves, they can run at up to 50 mph (80 km/h). They can see ultraviolet light, which helps them locate lichens and snow-covered vegetation on dark winter days. On the move Caribou are almost constantly on the move. Some migrate 3,000 miles (5,000 km) in a year—the longest distance any land mammal travels. Herds can be up to half a million strong, with smaller single-sex groups coming together to migrate during spring and fall. Males ﬁght for control of harems of females in fall and the females give birth to a single calf in the next spring. muzzle insulated by fur stout, rounded body under thick pelt Arctic fox Alopex lagopus Incredibly well-adapted to its harsh environment in the Arctic Circle, the Arctic fox can survive temperatures as low as -58˚F (-50˚C). Its dense fur is a few inches thick during winter, insulating its short ears, muzzle, and even the soles of its feet, which allows it to walk on ice without slipping. In winter, most Arctic foxes grow a white coat (some turn a steely blue) that lets them blend into the snow. Varied diet Although it feeds on smaller mammals such as lemmings, voles, and Arctic hares in summer, in winter the Arctic fox may dig out seal pups from their under-ice birth chambers. It will also follow polar bears and wolves to feed on carcasses they leave behind. The Arctic fox is the most common predator of Arctic birds such as snow geese, but also eats ﬁsh, eggs, seaweed, and berries. Mainly solitary, Arctic foxes may congregate around carrion or fresh kills, and regularly raid garbage dumps in northern Alaska. When not hunting, the Arctic fox curls up in underground burrows during summer, while in winter it tunnels into snow banks to escape blizzards. Females give birth in spring to litters of as many as 14 kits, or pups. Both parents raise their young until around August, when the family group disperses. The Arctic fox has the warmest pelt of any animal found in the Arctic 21—22 in (53—55 cm) 9 lb (4 kg) Common Small mammals, ﬁsh, birds N. Canada, Alaska, Greenland, N. Europe, N. Asia △ HUNTING IN THE SNOW The Arctic fox listens for movement below, then leaps into the air before plunging head-ﬁrst to the ground. This force breaks through the snow to the prey beneath. ◁ SUMMER COAT Arctic foxes’ white coats thin and change color to gray-brown in summer to match surrounding rocks and low-growing vegetation of the tundra. 28 | NORTH AMERICA ▷ AT HOME Snow dens protect young cubs from the cold. The dens have one entrance and often several chambers, and can be up to 40 degrees warmer than outside temperatures. ▷▷ STRONG SWIMMER A polar bear’s broad, partially webbed forepaws make it a superb swimmer, capable of covering up to 60 miles (100 km) at a stretch, at speeds of 6 mph (10 km/h). CANADIAN ARCTIC small ears to minimize heat loss Polar bear longer neck than other bears Ursus maritimus The polar bear vies with the brown bear for the title of the world’s largest living land carnivore. It is classiﬁed as a marine mammal, and its preferred hunting ground is Arctic pack ice. Superbly adapted to its environment, the polar bear has non-retractable claws and dimpled, partially furred foot pads that provide extra grip, allowing it to walk and run easily on ice. The polar bear’s body is covered in double-layered fur—the thickest of any bear species. The inner layer is a dense undercoat, while the outer fur consists of clear, hollow tubes that trap air for insulation. Since the tubes reﬂect all visible light, the outer coat makes polar bears seem white, allowing them to blend easily into snowy environments. Their skin is black and rests on a layer of blubber up to 4 in (10 cm) thick. Feasting and fasting Polar bears can live up to 25–30 years in the wild. Their lives alternate between feasting and fasting, and their intestines are adapted to process fat, which is easier to digest than meat and has more calories. They can also slow their metabolic rate when food is scarce. Their main diet is seals, but they occasionally hunt belugas or narwhals. When starving, they will also hunt walruses, but the risk of injury is high. They can smell prey up to 3 /4 mile (1 km) away, or up to 31/4 ft (1 m) beneath ice. Polar bears are generally solitary, except for breeding pairs or mothers with cubs. However, they will congregate around large food supplies such as whale Polar bears are capable of running as fast as an Olympic sprinter ◁ MOCK BATTLE Young males often engage in playﬁghting— sparring and trying to push each other over while standing on their hind legs. Some of these males may travel together for weeks or even years. carcasses. In fall, polar bears also gather together in “transition” areas such as southwestern Hudson Bay and Churchill, Canada to wait for the sea ice to form that allows them access to ringed seals swimming beneath the ice. Polar bear territories are vast. Bears closest to the Canadian Arctic Islands have an average range of 19,000–23,000 sq miles (50,000–60,000 sq km), but those closer to the Bering Sea can cover up to 135,000 sq miles (350,000 sq km). Winter births Polar bears give birth to cubs every two to three years —one of the lowest reproductive rates of all mammals. Mating occurs from late March through May, but embryos may not start to develop until fall. Pregnant females must gain about 440 lb (200 kg) extra weight during summer to survive the winter, when they may have to go up to eight months without food. They dig maternity dens mainly in south-facing snowdrifts, where between one and four cubs are born in early winter. Most litters are of twins. The adult female does not hibernate in the truest sense, but maintains a much warmer body temperature to care for her cubs. Even so, she neither eats, urinates, nor defecates during the months she is in the den. Mother and cubs do not emerge from their den until March or early April, when she leads them toward the sea ice in order to hunt. 6—9 ft (1.8—2.8 m) 880—1,500 lb (400—680 kg) Vulnerable Seals, ﬁsh, birds, vegetation Arctic Ocean, N. Canada, N. Russia | 29 30 | NORTH AMERICA tusk grows through upper lip Narwhal Monodon monoceros Narwhals are unique among whales in having a single long tusk, which is grown mostly by males. The tusk is, in fact, an elongated canine tooth that erupts mainly from the left side of the animal’s upper jaw. It grows in a counterclockwise spiral, and is believed to be the reality behind the unicorn legends of medieval Europe. While scientists once believed that the tusk’s function was purely defensive, relating to dominance disputes over mating rights, recent research has revealed millions of nerve endings at the tusk’s surface. These nerve endings allow the narwhal to detect changes in water pressure and temperature, as well as degrees of water salinity (saltiness). This discovery suggests that the characteristic rubbing of tusks by males may be a sensation- or information-seeking exercise—not simply “jousting.” Tusks can grow to over 8 ft (2.5 m) long and are highly ﬂexible, bending up to 1 ft (30 cm) in any direction without breaking. If a tusk is broken, new growth repairs the damage. Super pods Sociable animals, narwhals form small groups that often merge with others to form “super pods” of hundreds of whales. Individuals communicate by clicks, squeaks, and other vocalizations. Pods migrate each year, spending winters in and around the pack ice of the Arctic Ocean, and summers closer inland in bays or deep fjords. Their diet consists mainly of ﬁsh, such as halibut and cod, supplemented by squid. △ TIGHT SQUEEZE Restricted space can cause pods of narwhals to merge as they swim along narrow channels that have opened in the sea ice. Narwhals can dive to remarkable depths, some reaching 5,900 ft (1,800 m) ▷ UNICORNS OF THE SEA Male narwhals surface with their tusks pointing skyward. The dark staining is caused by algal growth. CANADIAN ARCTIC Beluga small, rounded ﬂippers Delphinapterus leucas The beluga is the only whale that is white in color when adult, a feature that helps it to hide from predators among the sea ice. If chased, the absence of a dorsal ﬁn allows the beluga to escape by swimming away beneath the ice. It is also able to move its head up and down and from side to side because its neck vertebrae are unfused. Thick blubber makes up 40 percent of its body mass. Every summer it molts, shedding the outer layer of skin, partially by raking its body over pebbles in shallow waters. Highly social mammals, belugas are also extremely vocal—their wide repertoire of clicks, whistles, chirps, and squeals has earned them the nickname “canaries of the sea.” ▷ BLOWING BUBBLES Belugas amuse themselves by blowing bubble rings and then biting them. They may also produce bubbles if alarmed or surprised. 10—15 ft (3—4.6 m) Up to 1.8 tons (1.6 metric tons) Near threatened Fish, squid, shrimp Arctic Ocean Harp seal Pagophilus groenlandicus 12—16 ft (3.7—5 m) Up to 2 tons (1.8 metric tons) Near threatened Fish, squid Named for their markings, harp seals are the most successful of all northern hemisphere seals, with numbers estimated at 8 million. Most inhabit icy northern waters, but some have migrated as far south as Virginia in the US and France. Mating occurs on pack ice in winter, and single pups are born from late February to mid March. Fast-moving on ice, harp seals are also good swimmers. Excellent eyesight and hearing make them formidable hunters, and also alert them to predators such as polar bears. black head markings of adult 6 ft (1.8 m) 286 lb (130 kg) Common Fish, krill ▽ HARP-SHAPED MARKINGS The dark markings on the sides of this adult seal curve upward to meet over the shoulders, forming a harp shape. Arctic Ocean, North Atlantic backward-directed hind ﬂippers Arctic Ocean | 31 32 | NORTH AMERICA oversized canine tooth rough, heavily creased skin Walrus Odobenus rosmarus This large marine mammal has a wide snout covered in hundreds of stiff, whiskerlike bristles called vibrissae, which help it to locate its food. Mollusks, such as mussels, are favorite foods, but walruses will eat the carcasses of young seals, usually when other food items are scarce. The song of the walrus Walruses travel in groups and “haul out” on land or ice. Females generally follow pack ice south in fall and north in spring, but most males stay all year in herds in the southern Arctic, only joining the females to mate. Bulls compete for mating locations by performing visual displays and intricate “songs,” and also spar with their tusks. A successful bull will mate with several cows between December and March, and the females give birth to a single calf in spring the following year. The average lifespan of walruses in the wild is 40 years. They can withstand icy conditions because of their thick skin and the presence of vast amounts of blubbery fat around their shoulders and neck. A walrus can slow its heartbeat to survive in icy water 8—12 ft (2.4—3.7 m) Up to 2.2 tons (2 metric tons) Not known Mollusks, octopuses, ﬁsh △ TOOTH PICKS Walruses use their tusks in defense and also as handy “ice picks” that help them pull themselves onto ice ﬂoes or land. They punch breathing holes through ice with their tusks, which grow about 1/2 in (1 cm) a year throughout their lives. ▷ COLD COMFORT Normally cinnamon-brown, walruses may turn pale after a long stay in icy water as blood vessels in their skin constrict to save body heat. In warmer weather, some walruses look pink as their vessels dilate to get rid of excess heat. Arctic Ocean and coasts CANADIAN ARCTIC Snowy owl mature male almost pure white Snow goose Chen caerulescens Nyctea scandiaca The snowy owl is a creature of the extremes, living in the High Arctic tundra. It is equipped with exceptionally thick plumage for insulation against the cold, the old males as white as a swan. Unusually among owls, females look different, with more dark spots and bars. Winter wanderings Snowy owls mostly feed on lemmings, surviving the long, dark Arctic winter and the extreme cold so long as they have food to eat. If food is scarce, they move south with regular winter migrations into central Canada and Siberia. Hundreds of snowy owls go farther south every few years as the populations of different lemming species boom and bust. Occasionally, they reach as far as Florida. Snowy owls breed every four or ﬁve years, with clutches of 3–13 eggs, and have barren years in between, so populations vary enormously. 21—28 in (53—71 cm) 2—6 lb (1—2.7 kg) Common Small mammals, birds long wings Snow geese breed in the extreme north of Arctic North America and migrate through western, central, and eastern states to winter in the far south. Hundreds of thousands of them stop to feed at regular “service stations,” with large, noisy ﬂocks making a spectacular sight. Despite the danger of being shot, they thrive on agricultural land, and they are highly sociable. 27—33 in (69—84 cm) 5—8 lb (2.3—3.6 kg) Common Grass, roots, seeds North America; Wrangel Island, Russia ▷ BRILLIANT WHITE Snow geese are found in two color forms: brilliant white (pictured) and blue-gray with a white head. Arctic char Salvelinus alpinus N. North America, NE. Europe, and N. Asia Adapted to deep water and extreme cold, Arctic char are the most northerly of freshwater ﬁsh. A migratory, river-breeding form lives in the sea, and there is also a landlocked lake form. Spawning occurs at 39.2˚F (4˚C). Females scrape shallow nests, or redds, to lay their eggs in clean gravel. Up to 38 in (97 cm) Up to 27 lb (12.3 kg) Common Insects, crustaceans ▷ GRACEFUL FLIER “Snowies” are huge owls, ﬂying low and silently between regular lookout perches on long, powerful, pointed wings. heavily feathered legs and toes | 33 N. North America, N. Europe, N. Asia, and Arctic Ocean ▷ FIGHTING MALES During breeding season, males become aggressively territorial. They develop hooked jaws and sport brilliant red undersides. black-tipped wings 3 4 | NORTH AMERICA YELLOWSTONE il si t e ye a y r ve r ❯ r wa t e r fa l l s a n d 5 0 0g eys e rs ❯ M or e majo 0 5 n3 a th PI NE THE WH Ope ITEB n ARK pine -canop ZO ied fore w hite NE sts cr nutc ow to s depen bark d u r con acker p rvive. C on a e r and s to ha ises op lark’s rv en t th he bird en cac est the hes seed forg t e s h t e s the m seed about s . The o s , m e of they which can m germ eans inat e. T K ❯ HI 0n average, Old Faithful produces columns of steam and water every 67 minutes EB AR am MILLER MO TH ❯ 3 m n vi s or GS 67 s p e c ies o fm ST FEA r H T le i MO of m l y s m n r o a illi as o er, m known grate t m i m in o u m In s hs (als oths) o feed st t t a m o v e m m ston Their izzly wor cut Yellow dows. gr to a act me rs attr me up us e n alpi umbe consu utritio es n n li hich the rizz rs, w 00 of . The g lse for a e e . b 0 40, s a day n little onths t m o c e inse en live o thre oft up t W Hot springs and geysers Around 1,700 species of plant live in the forests, meadows, and upland grasslands of the park, which also boasts mountains, lakes, rivers, and canyons. Yellowstone is also famous for being the world’s largest center of geothermal activity—it has around half of the known geothermal features on the planet, including the Old Faithful geyser. People also visit the park in the hope of seeing animals such as grizzly and black bears and American beavers, whose treefelling and stream-damming activities renew habitats such as pools, swamps, and meadows. lio al Lying within the South Central Rockies ecoregion and dominated by coniferous forest, Yellowstone was home to Native Americans for 11,000 years. Eighty percent of Yellowstone’s forests consist of lodgepole pine, a tree sonamed because its straight trunk is ideal for use as tipi poles. Yellowstone was established as a national park in 1872—the ﬁrst in the US and the world—and remains one of the largest, with more than 3,500 sq miles (9,000 sq km) of mostly pristine wilderness. The region is one of the last strongholds of American bison, and the reintroduction of the gray wolf in 1995 allows park managers to claim the area as the largest intact ecoregion in the northern temperate zone. The potentially damaging impacts of logging, hunting, and tourism are regulated, but not always successfully. T TH ge he ER ot loc MA ex he al te rm ize L A all per nde al h d e CTI w ow iod d p ea ffe VIT wh inte ing s, th lan t in cts Y t o c ro ere r—an biso inne -gro lud f un w n w e d. ate d ice to r sn ing Th rfo -f gra ow o r — e he rgan also ho wl f ee l ze in at ism h t s eed ake p o s to tol r gr era s wh me ings year , ow n os to m a c re in es e r dis ca an icro tin use ge o tiv e b the f an m ds . m America’s forested geothermal wilderness IN PR TS O H ❯ LA N CH DSCA AN P The GER E l o s fro m s of the Yello wolve s w 1 wit 920s stone hin me i n a a fe fore w nt t dam sts we year hat s r i n c a g e d e b e i n i ts r b wap easing y the g qua iti. In p numb to r king a articu ers of s l e wol gene pens ar, rate fa ves con . To iled are tro l wa helpin day, piti g onc to em ore . YELLOWSTONE Th e wo r l d ’s fir st na tio na LO C AT I O N The national park lies primarily within the western US state of Wyoming. It is part of the South Central Rockies ecoregion. M o n t a n a pa I IT AP W l | 35 rk ,e st Wyoming Idaho lis he 50 1 8 72 d in 0 miles 50 C L I M AT E ❯ Yellowstone experiences a cool, temperate climate, with cool summers and long, cold winters. Precipitation is evenly spread throughout the year, falling as heavy snow between November and March. LODGEPOLE P INE Ye ll o w s to n e’s °F °C 104 40 su per vo lc an o (West Yellowstone, Montana) MM IN 80 3 1⁄4 86 30 60 2 1⁄4 68 20 40 1 1⁄2 50 10 20 3 32 0 0 0 ⁄4 14 -10 -4 -20 Key Average temperature Rainfall S U P E RVO LC A N O i TO Na O M sla me UC jaw sh d fo H C th , cu of s r th OM P di reat tth carl e d ET fro sea ene roa et o ram ITIO in m se, d b t tr n t atic N Th trod oth and y h out he l se os uc er co abi are ow er ar par e in ed f ﬁsh mp tat th e a ate Ye or sp etit los a e d ke su llo sp ec ion s, th nd o iets y c bsp wst ort ies i s s de o om e on ﬁs cli ﬁsh pre f b po cies e a hin ne w y, s ald ne . T re g. i n o u o t ea n t h e a th ld he gl of y es als d es e e bi o le clin rd ad e so t o fp oa f re y. 0 km Rexburg Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec ab INGS pted GINN are ada E B s Y e l R n a i FIE ion ep epol ccas n Lodg e with o rees bur p t o y l e c t Th to igh e res. eir t wildﬁ y, but th quire th l re elt rapid cones to m eals e r d ﬁ e s d wil clo hat s s of a lue t d heat sinous g the see e ly g r n w i e e s a th en , rele in th them minate r to ge d area. e r c l ea st h e on on e on T y lan he nt di -T CUT U RO l wo r l d Y ONE WST ELLO TT OA HR Around 640,000 years ago, a massive volcano erupted, which caused it to collapse and form the giant Yellowstone Caldera. The supervolcano beneath the caldera is still active, and the caldera is closely monitored for signs of increasing activity. Between 1,000 and 2,000 earthquakes and tremors are recorded in the area every year. ❯ 36 | NORTH AMERICA dish-shaped face long front claws Grizzly bear Ursus arctos horribilis All grizzlies are brown bears, but not all brown bears are grizzlies. This subspecies gets its name from its light-tipped fur, yet not all are “grizzled”—their coats range from whitish-blond to almost black. Their shoulder “hump” consists of muscles that make them efﬁcient diggers and capable of inﬂicting strong blows with their forepaws. Despite its often fearsome reputation, the bulk of a grizzly bear’s diet comprises nuts, grasses, roots, seeds, and moths. Much of the meat they eat comes from carrion, but they hunt mammals ranging from ground squirrels to moose. Grizzlies prefer coniferous forests broken by ﬁelds and meadows with access to rivers. Good swimmers, they are skilled at catching trout, bass, and salmon. Grizzly threat Grizzlies mate in late spring to early summer. The female gives birth to up to four cubs, usually while hibernating, nursing them in her den until April or May. Cubs stay with their mothers for two to four years, and the main threat to youngsters is from adult male grizzlies. Once common throughout the western US, grizzlies now occur in small numbers only in Idaho, Montana, Washington state, and Wyoming, with larger populations in Alaska and Canada. 5—8 ft (1.5—2.4 m) 132—727 lb (60—330 kg) Locally common Berries, roots, carrion, ﬁsh NW. North America △ FOOD FIGHT Grizzlies are powerful bears and competition for the best ﬁshing spot can cause a ﬁght to break out. However, most will stop before a serious injury occurs. ◁ WHO’S THE DADDY? Female grizzlies will mate with several males in a breeding season and the cubs in the resulting litter may have different fathers. YELLOWSTONE large, sensitive ears help detect prey | 37 powerful, long legs Gray wolf Canis lupus Despite its name, the gray wolf can be black, brown, gray, or almost white. All gray wolves are pack predators, hunting large hooved mammals such as elk, deer, and caribou, and smaller prey such as rabbits and beavers. They also feed on carrion, particularly in winter. An average wolf pack has seven to eight adults ruled by an alpha male and female. The alpha pair leads hunts, establishes territory, and chooses den sites, reinforcing the pack’s bonds through vocalizations such as barks and howls. The alphas mate from January to March. After about three months, the female bears a litter of four to seven pups. The pack nurtures the pups until they are about 10 months old, when some will leave, traveling up to 500 miles (800 km), in search of other wolves. ▷ BUILT FOR STAMINA An adult gray wolf may range up to 45 miles (70 km) in a day and can run at top speeds of up to 45 mph (70 km/h). 3—5 ft (1—1.5 m) 35—132 lb (16—60 kg) Common Elk, deer, rabbits, carrion large feet and claws Successful reintroduction The light gray Rocky Mountain wolf subspecies (C. l. irremotus) was reintroduced to Yellowstone in 1995. Since the wolves’ return, elk and deer are more mobile, letting trees and grassland regenerate. 26—43 in (66—109 cm) 9—34 lb (4—15.4 kg) Common Rabbits, rodents, birds N. North America, Europe, Asia Each wolf has its own signature howl Bobcat Lynx rufus What the bobcat lacks in tail length it makes up in numbers. More bobcats live in North America than any other native cat species—estimates put the ﬁgure at more than a million. Also the most widely distributed cat, it is found as far north as British Columbia. Adaptable cat S. Canada, US, Mexico ▷ WINTER FREEZE Bobcats are more often seen in daylight hours during winter, when food is scarce. They are ambush predators, with markings that allow them to blend in with their surroundings. The secret to this tough little cat’s success is adaptability. It prefers dense forests, but can easily survive in swamps, mountains, and deserts. Recently, it has added suburban and urban terrain to its habitats. This often brings it into conﬂict with humans, as it preys on domestic pets and small livestock. In the wild, rabbits form a large part of a bobcat’s diet, but it also hunts rodents, birds, beavers, and small deer, mainly at dawn and dusk. At other times, it rests in dens hidden in thickets, hollow trees, or rocky crevices. Like most cat species, the bobcat is solitary except during the mating season from December to April. After about a two-month gestation period, females give birth to litters of about three cubs, which remain with their mothers for eight months. 38 | NORTH AMERICA Wolverine Gulo gulo Known as the glutton, albeit unfairly, the wolverine satisﬁes its voracious appetite by killing prey as big as deer. Its strong jaws rip open the toughest hides and crush the biggest bones in search of marrow. Although it is in fact a huge weasel, its heavy fur, sturdy legs, and large feet give the wolverine a bearlike appearance. It can walk on snow with its broad feet, and survive extreme conditions in remote forests, tundra, and mountains encircling the Arctic. Wolverines store food after a big kill. Reindeer and caribou are dismembered and buried in snow or soil, or pushed into rock crevices and gullies. They mate in summer and two to four cubs are born the following spring. ◁ PALMATE ANTLERS Male moose grow a new set of their massive antlers every summer. These have a covering of soft skin, or “velvet,” which is shed by autumn, the mating season. 26—41 in (65—105 cm) 13—40 lb (6—18 kg) Common Deer, hare, birds, fruit NW. to N. North America, NE. Europe to N. and E. Asia ▽ ON THE GO Short, powerful legs and a supple, shufﬂing action help the wolverine cover long distances at a relentless pace in search of food, with minimum expenditure of energy. ▽ LOSING BATTLE This female moose managed to defend her week-old calf from a pack of wolves for 10 minutes, but, despite her superior size and power, they were able to drag the calf away from her. YELLOWSTONE Moose Alces alces The world’s largest species of deer, the moose lives below the Arctic Circle, inhabiting coniferous and deciduous woodland, swamps, and lakes. In Europe, the moose is also known as the elk, whereas in North America—to add to the confusion—the elk is an entirely different species. Solitary nomads Unlike most other deer species, moose are mostly solitary, although females are accompanied by their calves. They do not defend territories, staying on the move all year round. Male moose select habitats that offer the greatest supply of food, while females choose habitats that provide the most cover for them and their young. Moose are diurnal browsers, and may be found cooling off in water during the hottest days of summer while feeding on lily roots and other aquatic plants. | 39 pointed hooves for digging in snow They use their ﬂexible upper lip to browse the freshest leaves and shoots. In winter, when leafy food is in short supply, they will kick away snow to get at moss and lichens underneath, chew on twigs of trees such as poplar and willow, and strip bark from trunks. Their wide hooves help them to walk on soft snow as well as wade through soft-bottomed lakes and swamps. Male moose rut in the fall, and both sexes bellow to attract a mate. The females choose a mate by sizing up his antlers, which may span over 6 ft (2 m) and have up to 20 points each. Rival males frequently joust for mating rights. Female moose give birth to one or two calves the following summer, which are weaned after six months. A healthy adult moose has little to fear from predators other than humans as it can use its antlers or hooves to defend itself, but bears and wolves predate the much smaller calves. 8—10 ft (2.4—3 m) 620—1,320 lb (280—600 kg) Common Leaves, lichen, water plants, moss, bark N. North America, N. Europe, N. and E. Asia 4 0 | NORTH AMERICA White-tailed deer Odocoileus virginianus Although widespread and found in large numbers, the white-tailed deer often stays out of sight. For most of the year, the deer live alone, occupying small home ranges of about a square mile. They set up home in swamps, woodlands, and scrubland—wherever there are plenty of shrubs to conceal them. They move slowly, constantly on the lookout for predators such as mountain lions. If danger appears, the deer whistle with alarm and bound away, waving their white tails to startle attackers. The deer’s territory provides all the food they need for the year, even in the northern fringe of their range where winters are long and severe. The deer do not leave when winter comes, but follow well-trodden paths through the snow looking for any greenery they can access. In winter, their coat is gray, but it thins in summer and turns red. 4—6 ft (1.2—1.8 m) 115—310 lb (52—140 kg) Common Buds, leaves, twigs, cacti S. Canada to N. South America Spotted disguise The females are ready to breed in fall, and males deploy their antlers to battle it out for the rights to each mate. Fawns are born in spring and lie hidden under shrubs while the mother is away feeding. They begin to follow their mothers in a month and are weaned when three months old. Their spotty coat, which helps them hide when young, is lost in the ﬁrst winter. ▷ MATURE BUCK Only male white-tailed deer have antlers, growing a fresh set each year. A new point, or tine, is added with each growth. American pika short, thick fur protects from the cold Ochotona princeps The American pika looks like a cross between a guinea pig—with short legs and a large head—and a rabbit, with round ears and a whiskered face. Its long tail is hidden in fur. Lively in daylight, the animal bounds across scree slopes, pausing to make birdlike “cheeps” that warn of ▷ MAKING HAY Pikas forage for grasses and herbs, eating some each day and caching the rest in their winter hay store. the presence of predators, such as coyotes, weasels, and stoats, or far-carrying “mews” to assert its territory. This consists of a foraging area and a den in a burrow or rock crevice. Pikas live next to a member of the opposite sex, giving a male–female patchwork of territories. In summer, the pika gathers ﬂowering stems, such as ﬁreweed, and long grasses. These are stored in a pile near its burrow and left to dry. As winter approaches, the pika drags its hay pile deep into a rock cavity, keeping its food store safe from the snow. Pikas select plants that will decompose the most slowly to ensure their food store will last them through the winter. This animal is adapted to high, cold places, but climate change has squeezed it into an ever-shrinking range. 6—9 in (15—23 cm) 4—6 oz (113—170 g) Locally common Grasses, herbs SW. Canada, W. US Pikas use their cheek glands to scent-mark their territory long whiskers enable beaver to feel its way in the dark American beaver Castor canadensis △ CLOSE LIPPED Beavers close their lips behind their incisor teeth when underwater so they can still nibble and gnaw on branches and stems. Woody diet They live in small colonies, led by a male and female who mate for life. The female gives birth to three or four fully furred kits between April and June. The kits leave after two years to form their own colonies. Beavers make their lodges along banks or lake shores, the most impressive being the island lodges in the middle of ponds. With an entrance only accessible underwater, these are the safest refuges from predators such as wolves and coyotes. They tailor their dams to rates of water ﬂow, building straight ones for slowmoving water, and curved ones for faster currents. The beavers’ long, orange incisors, which never stop growing, are perfectly suited to their diet of woody bark, twigs, and stems. They also eat cambium, a soft tissue under the bark; favorite sources include birch, alder, and aspen, which they often store as winter food. ▽ MASTER BUILDER American beavers make their dams and lodges out of logs, branches, grass, and moss, plastered together with mud. North America’s largest rodent, the American beaver, is a nocturnal “engineer” that alters landscapes throughout the continent, aside from desert areas and northernmost Canada. This stocky, big-skulled aquatic mammal fells trees by gnawing through the trunks, then arranges them into dams across streams or rivers, or uses them to build lodges for shelter. Its ﬂat, scaly tail and webbed hindfeet make it a graceful swimmer, and a waterproof coat protects it from the winter cold. 29—35 in (74—89 cm) 24—57 lb (11—26 kg) Common Woody bark, twigs, stems North America 42 | NORTH AMERICA ▷ FISHING EXPEDITION The bald eagle, like other sea eagles, does not enter the water to catch prey; instead, it swoops down to snatch ﬁsh, live or dead, from the surface of a lake. pure white hood ▷▷ DOWNY CHICK Bald eagle chicks remain in the nest for 10—13 weeks, entirely dependent on their parents for food, protection, and shelter. △ BODY RIPPER The ﬁercely hooked bill is not used to kill prey, but to rip it into chunks that can be swallowed, and to tear the hide off the carcass of larger animals. YELLOWSTONE | 43 black-brown body Bald eagle long talons Haliaeetus leucocephalus The bald eagle is found only in North America, but its image is used as a symbol of power, grace, and durability worldwide. Like many birds of prey, its bold looks suggest a more swashbuckling lifestyle than is really the case, for it spends much of the time doing nothing, and much of its food is carrion. It is doing what big birds of prey do: conserving energy between bouts of hunting and gorging. Life on the water’s edge long, sharp bill hook There are eight species of giant sea eagles worldwide, including the Eurasian white-tailed eagle, the African ﬁsh or river eagle, and the spectacular Steller’s sea eagle from far eastern Asia. All these species, including the bald eagle, have a powerful build and broad wings that are “ﬁngered” at the tip when fully spread, a relatively short tail and a long head and neck, creating a crosslike shape in ﬂight. Unlike golden eagles, bald eagles soar with their wings held ﬂat. All sea eagles have bare lower legs and feet, with strong toes and sharp claws to grip and pierce their prey, as well as a strong bill to tear it to pieces. Fish form a large part of the bald eagle’s diet, but it also eats other prey. Bald eagles can catch and kill animals as large as sea otters and birds up to the size of a goose. In summer, many live on seabirds caught in coastal colonies. They are primarily birds of 28—38 in (71—96 cm) 7—14 lb (3—6.5 kg) Common Fish, birds, mammals North America the water’s edge, where such prey items—and all kinds of wave-tossed carcasses and scraps—can be easily foraged. Living along the western seaboard of North America from Alaska to California, bald eagles penetrate far inland along rivers and around lakes. They breed across the far northern parts of Canada and in winter move south as far as Florida and the Gulf of Mexico— to wherever water can be found. Bald eagles feed in small groups in winter if enough food is available, and nest in small defended territories, covering about 3/4 sq mile (0.2 sq km). These sites can be grouped quite close together. Nests are built almost anywhere from near-ﬂat ground to small slopes, cliffs, exposed crags, and trees. Breeding pairs and trios Each pair of bald eagles usually has several nests— one preferred nest, a huge heap of sticks, grass, and seaweed, can become as large as 13 ft (4 m) deep and 8 ft (2.5 m) across. Although two eggs are the norm, usually only one chick survives to ﬂy. Up to threequarters of the young die before they are a year old, and only one in ten reaches ﬁve years of age. Bald eagles can start breeding when four years old. However, unusually, half the adults are non-breeders and some form trios at one nest. Once grown, adults may go on to live long, productive lives, surviving for almost 50 years in the wild. The bald eagle was chosen as the national bird of the US in 1782 4 4 | NORTH AMERICA CENTRAL GREAT PLAINS A rolling landscape, once covered in a sea of grass Conversion to agriculture As recently as the early 19th century, this vast area was still covered by grassland. Today, most of the fertile land is given over to agriculture. Overexploitation of arable land in the early 20th century led to the environmental and economic catastrophe in the 1930s known as the Dust Bowl, in which the topsoil was entirely lost from vast areas in a series of dust storms caused by drought and wind erosion. The land has mostly recovered sufﬁciently to support grazing, but the vast herds of bison that once roamed the prairies are largely gone, replaced mainly by domestic cattle. A few pockets of relatively pristine prairie remain in the US and Canada, and in reserves such as the Wichita Mountains Wildlife Refuge in Oklahoma, surviving bison herds are protected. Even here, trees are few, and large vegetation is limited mainly to mesquite scrub and prickly pear cactus. Only 1% of t he OR NA na TE tur BO X al TU RT gr as LE sl an ST PE on A ed NG MI o fe num . e CO d t ola BE use d, S had ee hts ted tle ee ie w nig plan the is b air ny rs s, Th a pr r spi ttle ecie etle , o n se sp e be me tum he um o, th beca est. t tra t w lan p ros Bu r So pota t and rop c e d ie oth ate its d rious an ltiv cu nged noto a a ch LIVIN The o G IN A rna BOX of two te box turt le is o terres ne t r the G ial tur tles o name reat Plains . They n d for t he ar shell, which ir hinged lo e wer c shut t o prot an be clam ect ped limbs the head a nd from Howe p r ver, m any o edators. killed f the trying to cro m are ss roa ds. d s v ur iv es ❯ P RADO COLO 30 ion mill E OTATO BEETL BOOM ING M The s ARVE pring matin LOUS the g g rit rea a new ter prairie uals of chick ecoto en ar u thank e s to c rism attra onser ction Male vation birds comp effort “boom ete s. in loud c g ground at regula r s,” ma alls a m air sa king cs on pliﬁed by inﬂat the n ed eck. Forming a broad band through North America almost to Mexico, between the Rocky Mountains and the Missouri River, the Central Great Plains was once an immense, gently rolling prairie landscape that was dominated by mixed grasses for millions of years. Succession by trees and scrub was kept down by wild ﬁres and grazing by native herbivores such as American bison, pronghorn antelope, and prairie dogs. The prairies were also home to a variety of reptiles, birds, and invertebrates, and many of these animals were exploited sustainably by nomadic American Indian tribes. b i s o n o n ce l i ve d o n t h PR AIR eG IE re a CH IC tP K l a i EN ns ❯ CENTRAL GREAT PLAINS Pronghorn LO C AT I O N Kansas City Dallas Houston ME XIC 0 km 250 O 0 miles 250 Central US, including parts of Nebraska, Kansas, Oklahoma, and Texas. Part of the larger Great Plains area, which extends north into Canada. C L I M AT E The pronghorn is the fastest land animal in the Americas, with a top recorded speed of 54 mph (87 km/h). However, its deﬁning feature is its horns. The forked, antlerlike headgear looks like that of a deer, and the pronghorn is also known colloquially as the American antelope. A deer sheds its antlers each year, while an antelope keeps one pair for life; the pronghorn keeps the bony core of the horn for life, shedding the keratin sheath over the bone each winter. 4—5 ft (1.2—1.5 m) 66—176 lb (30—80 kg) Locally common Forbs, leaves, grasses Home on the range Huge seasonal extremes of temperature, giving intensely cold winters and hot, humid summers. The region is subject to extreme weather events. °F °C 104 40 sensitive nose picks up scent of other pronghorns Antilocapra americana Denver UNITED STATES | 45 (Custer State Park, South Dakota) MM IN 100 4 86 30 75 3 68 20 50 2 50 10 25 1 32 0 0 0 The pronghorn is the sole surviving member of the Antilocaprinae family, which had dozens of species ﬁve million years ago. Despite their unique horns, pronghorns share many features with other even-toed ungulates— a herd lifestyle, a diet of leaves and grasses, and long legs. The pronghorn population was devastated by hunting in the 19th century. Today, pronghorn herds survive in the remote parts of the American West, which is appropriate as it is the very beast mentioned in the anthemic western song “Home on the Range.” W. and C. North America Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 14 -10 Key Average temperature En co mp as Y a SIT ER fox is st. V I D ift iali ING ive sw spec R O irie m ST nut RE dimi ss pra ce fro e g e a n n r Th rt-g eara s ra ical t sho isapp t of i colog n d Its perce ider e s to s i t 0 s 6 ect w rojec for th P t ﬂ . ta eﬁt re line abi dec ore h ill ben g t res ies w ludin irds. c c gb e n i p , s stin ers oth ndne u gro Rainfall A pronghorn can leap 20 ft (6 m) in a single bound ▽ RACING AWAY FROM DANGER Pronghorns live in loose herds, with large males controlling mating territories in summer. They warn each other of danger with snorts and by raising their white rump hairs. ses n To r SWIFT FOX l l ey ado A ▷ STAMPEDING HERD When alarmed, bison herds start to stampede and, at top speed, can reach 35 mph (60 km/h). CENTRAL GREAT PLAINS short, upturned horn American bison Bison bison The American bison is an iconic species of the vast prairies that once stretched from the Rocky Mountains east across central North America, from southern Canada as far south as Texas. Also known as the American buffalo, this massively built animal has a large head, thick neck, and a prominent hump behind the shoulders. Its front-heavy appearance is enhanced by a long beard and a shaggy shawl of fur around the neck and forelegs. Full-grown males weigh 2,100–2,200 lb (950–1,000 kg), which is twice as heavy as females. Despite their huge bulk, bison can run at speeds of up to 35 mph (60 km/h). Both sexes have a pair of short, upturned horns. Hunted almost to extinction Bison used to live in huge, nomadic herds that roamed across long distances to graze. The population numbered many millions, with 30 million living on the Great Plains. They had long been hunted by Native American tribes, but during the 1800s, European settlers moved into the prairies and hunting for meat and hide accelerated. The bison’s prairie habitat was converted to farmland, and by the 1880s, as few as 500–1,000 animals were left. An end to hunting and the creation of national parks have raised the bison population to about 30,000 free-ranging animals, although the species only occupies less than one percent of its former range. There are about 500,000 domesticated bison on private ranches and △ WINTER TRAVEL The bisons’ thick coat and heavy mane protect them from the cold. They are so well insulated that even a dusting of snow on their back does not melt. ◁ YOUNG BISON A calf can stand, walk, or run with its mother a couple of hours after it is born. The calves are weaned at about six months. 7—12 ft (2.1—3.5 m) 770—2,200 lb (350—1,000 kg) Locally common Grasses, sedges N., NW., and C. North America farms. However, the domesticated stock have been cross-bred with cattle and have lost many of their wild traits. Wild bison have excellent hearing and sense of smell, which are essential for detecting their chief natural predator, the gray wolf. Follow the grass Adult females and young live in groups of 10–60, led by an older cow. The bulls form separate herds or live alone. The breeding season is from July to September, when the bulls rejoin the female-led herds. The bulls ﬁght for mating rights and dominance, clashing heads in spectacular battles. The females give birth to a single calf after a 10-month gestation, usually in April or May when there is a fresh growth of spring grass. Bison have complex stomachs with four chambers to help them digest large quantities of grass, and they spend long periods chewing the cud. They can paw aside snow to reveal grass below, but in harsh winters, they migrate to lower, snow-free areas. Wood bison and wisent Some of the bison found in Canada are a separate subspecies known as wood bison (B. bison athabascae). The largest free-ranging herd of this species is found in Wood Buffalo National Park. There is also a population of wild bison in the Bialoweza Forest on the PolandBelarus border, and these may belong to a second species called the European bison, or wisent (B. bonasus). An adult American bison could leap over an adult human | 47 4 8 | NORTH AMERICA Black-tailed prairie dog Cynomys ludovicianus A large species of ground squirrel, black-tailed prairie dogs are highly social rodents. They live in “towns”—extensive networks of underground tunnels and chambers. A town houses hundreds of dogs, all organized into smaller groups called coteries. A coterie, made up of a dozen adults and their offspring, works together to maintain their patch of the tunnel and defend it from intruders. Coterie members share a scent, which marks them out from other groups. Prairie dogs dig their tunnels deep enough to avoid winter frosts. Any loose earth pushed to the surface forms mounds around the tunnel entrances that are ideal for spotting predators. 14—17 in (36—43 cm) 2—3 lb (0.9—1.4 kg) Common Grass, sedge ▷ FAMILY UNIT Pups emerge from under the ground at the age of six weeks and are looked after by every member of the coterie. Most males leave the group after their ﬁrst winter. SW. Canada to N. Mexico Black-footed ferret Mustela nigripes This solitary, burrowing hunter is one of North America’s rarest mammals. Numbers fell to 18 in the mid-1980s, but are now increasing again. About 90 percent of the black-footed ferret’s diet is made up of prairie dogs. The ferrets dig their dens right in the middle of prairie dog communities, even setting up home in unused sections of their tunnel network. They can follow prairie dogs into their burrows, killing and eating them underground. 16—20 in (41—51 cm) 2—3 lb (0.9—1.4 kg) Endangered Prairie dogs, mice, squirrels ▽ DISTINCTIVE MASK Male and female ferrets have a well-deﬁned mask around the eyes from an early age. Reintroduced to C. US CENTRAL GREAT PLAINS | 49 grizzled red and gray coat small feet Coyote Canis latrans Most wild dog species face enormous pressure from humans encroaching on their wide-ranging habitats. However, the coyote is thriving, even encroaching on human habitats as a proﬁcient poacher of poultry and scavenger of human garbage. Somewhere between a fox and wolf in size, the coyote has a highly adaptable lifestyle. Although it may form packs to hunt large animals such as deer, mostly it is a solitary hunter, targeting smaller prey—such as prairie dogs—alone. Coyotes spend the day in an underground den; they may dig their own den, but usually enlarge one abandoned by badgers or ground squirrels. Involved parenting When raising offspring, coyotes set out their home ranges by marking bushes and other landmarks with urine and feces. They assert their claim on the territory with loud yips and howls. Coyotes may form pair bonds that last several years. Mating occurs in late winter, and about six pups are born two months later. Both parents nourish the youngsters with regurgitated food in the den. Coyotes work with American badgers to hunt burrowing rodents ◁ HOWLING COYOTE Coyotes are noisy animals, frequently howling to lay claim to a territory or greet a family member. 29—37 in (74—94 cm) 17—35 lb (7.7—15.9 kg) Common Mammals, insects, fruit North America and N. Central America 50 | NORTH AMERICA Greater sage-grouse Centrocercus urophasianus America’s largest grouse lacks a muscular gizzard and cannot digest hard seeds and shoots. It relies on various kinds of sagebrush for food and cover. During the breeding season, females watch males display at a lek, a communal display ground. They select the strongest males to mate with. A few dominant males mate with the females and hens lay six to nine eggs. The chicks are fully mobile after six to eight weeks, when families may move to winter ranges at lower altitudes in search of food. 19—30 in (48—76 cm) 3—7 lb (1.4—3.2 kg) Near threatened Sagebrush, insects W. to C. North America Common garter snake Thamnophis sirtalis One of North America’s most widespread reptiles, the common garter snake frequents all but very dry or very cold habitats. Across its cooler, northern range, individuals gather in burrows, caves, and similar sites to overwinter, conserving energy by slowing their metabolism. In late summer, females have litters of 10–70 babies. 20—49 in (51—125 cm) 5—7 oz (141—198 g) Common Worms, ﬁsh, amphibians North America ▽ STRIPES OR SPOTS This species typically has three light stripes running lengthwise, but some garter snakes have rows of spots. heavily keeled scales ▽ STRUT DISPLAY When displaying at a lek, male sage-grouse rapidly inﬂate and deﬂate their breast air sacs to produce loud, far-carrying, bubbling, popping sounds. They also spread their pointed tail feathers. Striped scorpion Centruroides vittatus By day, the striped scorpion lurks in damp nooks under rocks and logs, and in thick vegetation. It emerges at sunset to hunt, detecting prey by their smell and movement with the help of comblike sensory organs between its last set of legs. The scorpion then crushes victims with its pincers and kills them with its stinger. Females produce young after an estimated gestation of about eight months. The 30–50 offspring are carried on their mother’s back until they molt for the ﬁrst time. ▷ PERFECT CAMOUFLAGE The scorpion’s coloring helps to hide it from predators as well as prey. 2—3 in (5—7.6 cm) Not known Insects, spiders, centipedes C. North America to N. Central America two broad stripes along back CENTRAL GREAT PLAINS 3—4 in (7.6—10.2 cm) Common Milkweed leaves; nectar black and white markings on wing tips Monarch butterfly Danaus plexippus N. America to N. South America The beautiful monarch is a familiar sight in North America. In autumn, monarchs that live west of the Rocky Mountains migrate to coastal California, while those from the east of the Rockies ﬂy south to a small highland area in Michoacán, Mexico. Survivors of the Mexican winter move north to Texas and Oklahoma in March, producing a new generation that spreads northward once more. Third and fourth generations continue the spread north through the US and Canada, and return south in autumn. Predators beware The monarch’s bright, contrasted coloration advertises its unpalatability to predators. The caterpillar absorbs steroids from the sap of the milkweed plant that are toxic to predators. However, wasps and various birds can eat the caterpillar: orioles detect the poison and vomit after eating it, while grosbeaks have a degree of immunity and digest butterﬂies without suffering any harmful effect. Monarchs are threatened by pesticide use in the US, which kills the milkweed plant, their food, and by logging in Mexico, which reduces their habitat and leaves them susceptible to cold and rain. The Monarch Butterﬂy Biosphere Reserve in Michoacán, where they overwinter, was declared a World Heritage Site in 2008. ▽ MASS MIGRATION Millions of monarchs migrate south in fall. They use stored fat to fuel their ﬂight, and may glide on air currents to save evergy. ▷ FEEDING ON MILKWEED The milkweed plant sustains the monarch butterﬂy by supplying it with leaves, sap, and nectar. | 51 52 | NORTH AMERICA SIERRA NEVADA California’s snowy backbone Forest and climate zones The Sierra Nevada’s western foothills are cloaked in savanna and deciduous oak woodland, but the rest of the range rising toward the east is dominated by coniferous forest, starting with juniper and Ponderosa and Jeffrey pines at lower altitudes. Giant sequoias start to appear at about 3,280 ft (1,000 m), and higher still, the forests are dominated by lodgepole pines, red and white ﬁr, and eventually, whitebark pine. Finally, the trees give way to hardy alpine plants at about 10,500 ft (3,200 m). The forests are interspersed with rivers and lakes, wet and dry meadows, and extensive areas of brushland. The wide range of altitudes and climates in the Sierra Nevada is reﬂected in the diverse wildlife. Animals living at higher altitudes, such as alpine chipmunks and pikas, must be able to tolerate low temperatures and snow for much of the year. The mountains are also home to both black and brown bears, bald eagles, and increasing numbers of American beavers. E IN CL ey DE s k IN , thi lined ite OR ad ec AT pre s d esp rs ED es ha . D be PR wid ator ping num ain m ss