Parachuting Cats Into Borneo
In the early 1950s, there was an outbreak of a serious disease called malaria amongst the Dayak people in Borneo. The World Health Organization tried to solve the problem. They sprayed large amounts of a chemical called DDT to kill the mosquitoes that carried the malaria. The mosquitoes died and there was less malaria. That was good. However, there were side effects. One of the first effects was that the roofs of people's houses began to fall down on their heads. It turned out that the DDT was also killing a parasitic wasp that ate thatch eating caterpillars. Without the wasps to eat them, there were more and more thatch-eating caterpillars. Worse than that, the insects that died from being poisoned by DDT were eaten by gecko lizards, which were then eaten by cats. The cats started to die, the rats flourished, and the people were threatened by outbreaks of two new serious diseases carried by the rats, sylvatic plague and typhus. To cope with these problems, which it had itself created, the World Health Organization had to parachute live cats into Borneo. pzweb.harvard.edu/ucp/curriculum/ecosystems/s6_res_borneo.pdf
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Core Case Study: The Passenger Pigeon: Gone Forever Passenger pigeon hunted to extinction by 1900 Commercial hunters used a "stool pigeon Archeological record shows five mass extinctions Human activities: hastening more extinctions?
Sustaining Biodiversity: The Species Approach Chapter 9
The last word in ignorance is the man who says of an animal or plant, "What good is it?" If the land mechanism as a whole is good, then every part is good, whether we understand it or not. If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering. Aldo Leopold, Round River: From the Journals of Aldo Leopold
Human Activities Are Destroying and Degrading Biodiversity Human activity has disturbed at least half of the earth s land surface Fills in wetlands Converts grasslands and forests to crop fields and urban areas Degraded aquatic biodiversity
Extinctions Are Natural but Sometimes They Increase Sharply Background extinction Extinction rate 0.01% -0.1% 100-1000X Mass extinction: causes? Levels of species extinction Local extinction Ecological extinction Biological extinction
Some Human Activities Cause Premature Extinctions; the Pace Is Speeding Up Conservative estimates of extinction = 0.01-1.0% Growth of human population will increase this loss Rates are higher where there are more endangered species Tropical forests and coral reefs, wetlands and estuaries sites of new species being destroyed Speciation crisis
Effects of a 0.1% Extinction Rate
Animal Species Prematurely Extinct Due to Human Activities
Endangered and Threatened Species Are Ecological Smoke Alarms Endangered species Threatened species, vulnerable species Characteristics of such species IUCN Red List
Characteristics of Species That Are Prone to Ecological and Biological Extinction
Percentage of Various Species Threatened with Premature Extinction
Natural Capital Degradation: Endangered Orangutans in a Tropical Forest $$$...?
Natural Capital: Nature s Pharmacy
Science Focus: Using DNA to Reduce Illegal Killing of Elephants for Their Ivory 1989 international treaty against poaching elephants Poaching on the rise Track area of poaching through DNA analysis of elephants Elephants damaging areas of South Africa: Should they be culled? Wildlife CSI
Are We Ethically Obligated to Prevent Premature Extinction?
Loss of Habitat Is the Single Greatest Threat to Species: Remember HIPPCO 1. Habitat destruction, degradation, and fragmentation 2. Invasive (nonnative) species 3. Population and resource use growth 4. Pollution 5. Climate change 6. Overexploitation
Causes of Depletion and Premature Extinction of World Species
Natural Capital Degradation: Reduction in the Ranges of Four Wildlife Species 1
Science Focus: Studying the Effects of Forest Fragmentation on Old-Growth Trees Tropical Biologist Bill Laurance, et al. How large must a forest fragment be in order to prevent the loss of rare trees? Habitable Planet
Science Focus: Why Should We Care about Bats? Vulnerable to extinction Slow to reproduce Human destruction of habitats White Nose Syndrome Important ecological roles Feed on crop-damaging nocturnal insects Pollen-eaters Fruit-eaters Unwarranted fears of bats
Science Focus: Vultures, Wild Dogs, and Rabies: Unexpected Scientific Connections Vultures poisoned from diclofenac in cow carcasses More wild dogs eating the cow carcasses More rabies spreading to people
WSB - 2015
Some Deliberately Introduced Species Can Disrupt Ecosystems Most species introductions are beneficial Food Shelter Medicine Aesthetic enjoyment 2 Nonnative species may have no natural Predators Competitors Parasites Pathogens
Some Harmful Nonnative Species in the United States
Case Study: The Kudzu Vine Imported from Japan in the 1930s The vine that ate the South Could there be benefits of kudzu?
Prevention Is the Best Way to Reduce Threats from Invasive Species Prevent them from becoming established Learn the characteristics of the species See next slide Set up research programs Try to find natural ways to control them
Characteristics of Invader Species and Ecosystems Vulnerable to Invading Species
What Can You Do? Controlling Invasive Species
More Causes of Species Extinction Population growth (& Overconsumption) Pollution Pesticides 4 DDT: Banned in the U.S. in 1972 Bioaccumulation Biomagnification 3
Bioaccumulation and Biomagnification
Big Yellow Taxi
Case Study: Where Have All the Honeybees Gone? Honeybees responsible for 80% of insect-pollinated plants Dying due to? Pesticides Parasites Bee colony collapse syndrome Bee Colony Collapse
More Causes of Species Extinction Climate Change 5
Case Study: Polar Bears and Global Warming Environmental impact on polar bears Less summer sea ice PCBs and DDT 2007: Threatened species list IUCN Ursus maritimus
More Causes of Species Extinction Overexploitation 6
Illegal Killing, Capturing, and Selling of Wild Species Threatens Biodiversity Poaching and smuggling of animals and plants Animal parts Pets Plants for landscaping and enjoyment Prevention: research and education
Animation: Humans affect biodiversity
Solutions
International Treaties Help to Protect Species 1975: Convention on International Trade in Endangered Species (CITES) Signed by 172 countries CITES Convention on Biological Diversity (BCD) Focuses on ecosystems Ratified by 190 countries (not the U.S.) CBD
Case Study: The U.S. Endangered Species Act Endangered Species Act (ESA): 1973 and later amended in 1982, 1983, and 1985 Identify and protect endangered species in the U.S. and abroad Hot Spots Habitat Conservation Plan (HCP) colony Mixed reviews of the ESA Weaken it Repeal it Modify it Strengthen it Simplify it Streamline it
Confiscated Products Made from Endangered Species
Science Focus: Accomplishments of the Endangered Species Act Species listed only when serious danger of extinction Takes decades for most species to become endangered or extinct More than half of the species listed are stable or improving Budget has been small Suggested changes to ESA Increase the budget Develop recovery plans more quickly Establish a core of the endangered organism s survival habitat
We Can Establish Wildlife Refuges and Other Protected Areas 1903: Theodore Roosevelt Wildlife refuges Most are wetland sanctuaries More needed for endangered plants Could abandoned military lands be used for wildlife habitats?
Gene Banks, Botanical Gardens, and Wildlife Farms Can Help Protect Species Gene or seed banks Preserve genetic material of endangered plants Botanical gardens and arboreta Living plants Farms to raise organisms for commercial sale
Zoos and Aquariums Can Protect Some Species Techniques for preserving endangered terrestrial species Egg pulling Captive breeding Artificial insemination Embryo transfer Use of incubators Cross-fostering Limited space and funds Critics say these facilities are prisons for the organisms
What Can You Do? Protecting Species
Case Study: Trying to Save the California Condor Largest North American bird Nearly extinct Birds captured and breed in captivity By 2007, 135 released into the wild Threatened by lead poisoning
The Precautionary Principle When substantial preliminary evidence indicates that an activity can harm human health or the environment, we should take precautionary measures to prevent or reduce such harm, even if some of the cause-and-effect relationships have not been fully established, scientifically.
Wolf Conservationists Winter Use Enthusiasts Ranchers Goal... Find a solution