LIVING IN THE ENVIRONMENT 17 TH MILLER/SPOOLMAN Chapter 9 Sustaining Biodiversity: The Species Approach

Core Case Study: Polar Bears and Global Warming 20,000-25,000 found in _____ populations scattered across the frozen Arctic Throughout the winter, polar bears hunt for seals on ____________ ice 19 floating

Core Case Study: Polar Bears and Global Warming During the summer, polar bears live off their stored fat until hunting resumes when the ice __________ again during winter Environmental impact on polar bears Due to atmospheric warming, ice is melting ___________ and breaking up ____________ in the winter Results in a _________________ hunting season and ______________ expands fasterearlier shorter weaker bears

Core Case Study: Polar Bears and Global Warming Estimated that polar bears may be gone from wild by 2100, existing only in _________ 2008: Threatened species list Alaska state government officials are trying to get this repealed because it may hurt economic __________ in their state Oil and coal industries fear the law may be used regulate the release of CO 2 where oil and coal are __________ Scientists project that human activities will lead to the extinction of _____ to ______ of the world’s plant and animal species. zoos growth burned 1/41/2

9-1 What Role Do Humans Play in the Extinction of Species? Concept 9-1 Species are becoming extinct 100 to 1,000 times faster than they were before modern humans arrived on the earth (the background rate), and by the end of this century, the extinction rate is expected to be 10,000 times the background rate.

Extinctions Are Natural but Sometimes They Increase Sharply (1) Biological extinction - _____ species member alive Can lead to secondary extinctions of species with ______________ connections to the species already gone extinct Background extinction - _______________ low rate of extinction Extinction rate - percentage or number of species that go extinct in a certain _________ ___________ no strong natural timeperiod

Extinctions Are Natural but Sometimes They Increase Sharply (2) Mass extinction - the extinction of many species in a relatively ____________ period of geological time Scientists argue over how many… ______ events From global changes in environmental conditions: major climate change, volcanoes, asteroid impacts After each mass extinction biodiversity eventually _______________, but each recovery required _______________ of years short returns millions

Some Human Activities Are Causing Extinctions A growing body of evidence indicates that extinction rates have accelerated along with the expansion of the human population… Human activity has disturbed at least half, more likely _______ of the earth’s land surface Filling in ________________ Converts grasslands and forests to ________ fields and ___________ areas Polluted or disturbed almost _________ of our surface water 80% wetlands crop urban half

Extinction Rates Are Rising Rapidly (1) Current extinction rate is at least _______ times higher than typical background rate of.0001% May rise to ______________ times the background rate by the end of the century This will equal a _______ extinction rate per year, causing ¼ to ½ of the world’s plant and animal species to disappear by the end of the current ______________ ,000 1% century

Most extinction experts actual consider to the projected extinction rate of 1% a year to be on the _________ side Continued ____________ of human population and our resource use Rates are much higher than the global average in certain parts of the world (biodiversity ________________) Tropical forests and coral reefs, wetlands and estuaries—sites of ________ species—being destroyed Extinction Rates Are Rising Rapidly (2) low growth hotspots new

Endangered and Threatened Species Are Ecological Smoke Alarms (1) Biologists classify species that are heading toward biological extinction as either… Endangered species - So few members that the species could __________ become extinct Threatened species - __________________ species Still enough members to survive, but numbers are __________________ -- may soon be endangered soon vulnerable declining

Four critically endangered species…numbers estimate individuals remaining in the wild Endangered Natural Capital: Species Threatened with Premature Extinction Sumatran tiger less than 60 Mexican Gray Wolf about 60 California Condor 172 Whooping Crane 210

Endangered and Threatened Species Are Ecological Smoke Alarms (2) Some species have characteristics that increase their chances of becoming extinct… Big Slow Tasty Valuable parts Behaviors that make them easy to kill…like nesting in __________ flocks large

Stepped Art Fixed migratory patterns Blue whale, whooping crane, sea turtle Feeds at high trophic level Bengal tiger, bald eagle, grizzly bear Narrow distribution Elephant seal, desert pupfish Commercially valuable Snow leopard, tiger, elephant, rhinoceros, rare plants and birds Low reproductive rate Blue whale, giant panda, rhinoceros CharacteristicExamples Rare African violet, some orchids Large territories California condor, grizzly bear, Florida panther Specialized niche Blue whale, giant panda, Everglades kite Fig. 9-3, p. 194

Fig. 9-4, p. 194 Percentage of Various Species Threatened with Premature Extinction Why do you think plants and fish are toward the top? deforestation overfishing

Science Focus: Estimating Extinction Rates Three problems with estimating extinction rates… 1.Hard to document due to ___________ length of time 2.Only ________ million species identified out of the estimated __________ million species 3.Little known about nature and _________________ roles of species identified Approaches 1.Study extinction rates over last 10,000 years and then compare with the __________ record 2.Use species–__________ relationship 3.___________________ models – population viability analysis (PVA) models long ecological fossil area mathematical

Case Study: The Passenger Pigeon: Gone Forever Once one of the world’s most abundant birds…a flock would darken the sky and take ______ days to fly overhead (John James Audubon – 1813) Reasons for extinction? Habitat loss Commercial hunting – tasty, feathers were used for pillows, bones used for fertilizers Easy to kill: flew in large flocks and nested in dense colonies 3

Fig. 9-6, p. 195 Natural Capital Degradation: Endangered Orangutans in a Tropical Forest

9-2 Why Should We Care about the Rising Rate of Species Extinction? Concept 9-2 We should prevent the premature extinction of wild species because of the economic and ecological services they provide and because they have a right to exist regardless of their usefulness to us.

Species Are a Vital Part of the Earth’s Natural Capital (1) Four reasons to prevent extinctions 1.Species provide natural _______________ and natural __________________ Insects for pollination Birds for pest control Play roles in key ecosystem functions 2.Most species contribute ___________________ services Plants for food, fuel, lumber, _________________ ______________________ (wildlife tourism) resources services economic medicine ecotourism

Fig. 9-7, p. 196 Pacific yew Taxus brevifolia, Pacific Northwest Ovarian cancer Rosy periwinkle Cathranthus roseus, Madagascar Hodgkin's disease, lymphocytic leukemia Rauvolfia Rauvolfia sepentina, Southeast Asia Anxiety, high blood pressure Neem tree Azadirachta indica, India Treatment of many diseases, insecticide, spermicides Foxglove Digitalis purpurea, Europe Digitalis for heart failure Cinchona Cinchona ledogeriana, South America Quinine for malaria treatment Natural Capital: Nature’s Pharmacy

Species Are a Vital Part of the Earth’s Natural Capital (2) 3.Analysis of past mass extinctions indicates it will take ___________________ years to regain species biodiversity 4.Many people believe species have an intrinsic _______________ to exist 5-10 million right

Review Questions What is the projected percentage for future extinction rates per year (that is on the low side)? What are three different methods for estimating extinction rates? 1 % Comparing past 10,000 years to fossil records Using species-area relationships Using mathematical models

Review Questions What characteristics led to the extinction of the passenger pigeon? What are four major reasons to prevent our activities from causing the extinction of species? tastyCommercial value – feathers and bones Easy to kill – fly and nest in large flocks Habitat loss Provide natural resources/services Economic value 5-10 million years recovery timeRight to exist