2.  Passenger pigeon hunted to extinction by 1900  Commercial hunters used a "stool pigeon”  Geological record shows five mass extinctions  Human activities: hastening more extinctions?

4.  We are degrading and destroying biodiversity in many parts of the world, and these threats are increasing.  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.

5.  The extinction of the Passenger Pigeon had two major causes: commercial exploitation of pigeon meat on a massive scale [25] and loss of habitat. [77] [25] [77]

6.  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

7.  Background extinction- The ongoing extinction of individual species due to environmental or ecological factors such as climate change, disease, loss of habitat, or competitive disadvantage in relation to other species. Background extinction occurs at a fairly steady rate over geological time and is the result of normal evolutionary processes, with only a limited number of species in an ecosystem being affected at any one time.  Background extinction rate, also known as ‘normal extinction rate’, refers to the standard rate of extinction in earth’s geological and biological history before humans became a primary contributor to extinctions. This is primarily the pre-human extinction rates during periods in between major extinction events.extinctionextinction events

8. Mass extinction: causes Poorly understood, but involve global changes in environmental conditions.  Levels of species extinction Local extinction, or extirpation- Local extinction, or extirpation, is the condition of a species (or other taxon) which ceases to exist in the chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions.speciestaxon  Ecological extinction- is defined as “the reduction of a species to such low abundance that, although it is still present in the community, it no longer interacts significantly with other species.” [1] [1]  Ecological extinction stands out because it is the interaction ecology Biological extinction- extinction is the end of an organism or of a group of organisms (taxon), normally a species. organismtaxonspecies

9.  Habitat destruction  Over-hunting (extirpation, poaching, etc)  Pollution of water, land, and air (global warming appears to be causing harm to some species, especially amphibians).  Habitat fragmentation (isolating tiny populations, preventing animals from finding mates).

11.  Endangered species – so few individual survivors that could be soon become extinct. International Union for the Conservation of Nature (IUCN), or the World Conservation Union.  Since 1960, published Red List  In 2007, listed 16, 306 animals and plants that are in danger of extinction—60% higher than in 1995.  Threatened species - threatened species are any species which are vulnerable to endangerment in the near future.endangerment

12. Grizzly bear Kirkland’s warbler Knowlton cactus Florida manatee Africanelephant Utah prairie dog Swallowtailbutterfly Humpback chub Golden lion tamarin Siberian tiger Giant panda Black-footedferret Whooping crane Northern spotted owl Blue whale Mountain gorilla Florida panther California condor Hawksbill sea turtle Black rhinoceros Figure 9.4 Endangered natural capital. S ome species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and roughly 1,300 of those in the United States are officially listed as being in danger of becoming extinct. Most biologists believe the actual number of species at risk is much larger.

13. 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 (K-strategist) 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 Figure 9.5 Characteristics of species that are prone to ecological and biological extinction.

15.  Three problems Hard to document due to length of time Only 1.8 million species identified Little known about nature and ecological roles of species identified  Document little changes in DNA Suggests species survive for 1 to 10 million years before going extinct.  Use species–area relationship On average, 90% loss of habitat results in a 50% loss of species living in that habitat.  Mathematical models

16.  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.  “It will take 5-10 million years for natural speciation to rebuild the biodiversity we are likely to destroy during your lifetime.”

20.  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?

21.  Intrinsic value, or existence value Species have an inherent right to exist and play their ecological roles, regardless of their usefulness to us.  Edward O. Wilson: biophilia phenomenon  Biophobia

22.  The greatest threats to any species are (in order) loss or degradation of its habitat, harmful invasive species, human population growth, pollution, climate change, and overexploitation.

23.  Habitat destruction, degradation, and fragmentation  Invasive (nonnative) species  Population and resource use growth  Pollution  Climate change  Overexploitation

24. Figure 9.11 Natural capital degradation: reductions in the ranges of four wildlife species, mostly as the result of habitat loss and hunting. What will happen to these and millions of other species when the world’s human population doubles and per capita resource consumption rises sharply in the next few decades? Question: Would you support expanding these ranges even though this would reduce the land available for people to grow food and live on? Explain. (Data from International Union for the Conservation of Nature and World Wildlife Fund)

25.  Globally, habitat loss, greatest in temperate biomes, pace picking up in tropics.  Endemic species Hawaii, the extinction capital of America—63% of species at risk.  Habitat islands  Habitat fragmentation The Bali Mynah is distributed and endemic to the island of Bali, where it is the island's only surviving endemic species. This rare bird was discovered in 1910 and is one of the world's most critically endangered birds. In fact, it has been hovering immediately above extinction in the wild for several years.

26. NumbersLocationReason(s) 75% of birds speciesSumatra’s lowland forestsLumber and palm plantations, used for biofuels 115 bird speciesBrazilBurning/clearing of rainforests for farms and ranches; 93% loss of Atlantic coastal rainforest; clearing of savannah-like cerrado for soybean plantations 30% of bird species, 70% of grassland species North AmericaHabitat loss and fragmentation of breeding habitat; replaced by roads and other developments. 28% of speciesWorldwideIntroduction of non-native bird-eating species 52 of 388 parrot speciesWorldwidePet trade 23 SeabirdsWorldwideBycatch from commercial fishing; pollution 40% of waterbirdsWorldwideLoss of wetlands

27.  Seabirds caught and drown in fishing equipment  Migrating birds fly into power lines, communication towers, and skyscrapers  Other threats Oil spills Pesticides Herbicides Ingestion of toxic lead shotgun pellets

28.  Greatest new threat: Climate change  Environmental indicators Live in every climate and biome Respond quickly to environmental changes Easy to track  Economic and ecological services

30. Cerulean warbler Sprague’s pipit Bichnell’s thrush Black-capped vireo Golden-cheeked warbler Florida scrub jay California gnatcatcher Kirtland'swarbler Henslow's sparrow Bachman's warbler Figure 9.13 The 10 most threatened species of U.S. songbirds. Most of these species are vulnerable because of habitat loss and fragmentation from human activities. An estimated 12% of the world’s known bird species may face premature extinction due mostly to human activities during this century. (Data from National Audubon Society)

31.  Vultures poisoned from diclofenac in cow carcasses  More wild dogs eating the cow carcasses  More rabies spreading to people

32. Figure 9.14 Some of the more than 7,100 harmful invasive (nonnative) species that have been deliberately or accidentally introduced into the United States.

34.  Imported from Japan in the 1930s to control soil erosion.  “ The vine that ate the South”  Could there be benefits of kudzu?

36.  Argentina fire ant: 1930s Pesticide spraying in 1950s and 1960s worsened conditions  Wiped out competitor ant species and made them more pesticide resistant.  Burmese python

40.  Population growth  Overconsumption  Pollution  Climate change

41.  Pesticides DDT: Banned in the U.S. in 1972  Bioaccumulation  Biomagnification

43.  Poaching and smuggling of animals and plants Animal parts Pets Plants for landscaping and enjoyment  When commercially valuable species become endangered, black market prices soar.  Prevention: research and education

47.  We can use existing environmental laws and treaties and work to enact new laws designed to prevent species extinction and protect overall biodiversity.  We can help to prevent species extinction by creating and maintaining wildlife refuges, gene banks, botanical gardens, zoos, and aquariums.

48.  Concept 9-4C According to the precautionary principle, we should take measures to prevent or reduce harm to the environment and to human health, even if some of the cause-and-effect relationships have not been fully established, scientifically.

50.  Gene or seed banks Preserve genetic material of endangered plants  Botanical gardens and arboreta Living plants  Farms to raise organisms for commercial sale

51.  Techniques for preserving endangered terrestrial species Egg pulling Captive breeding Artificial insemination Embryo transfer Use of incubators Cross-fostering

52.  Limited space and funds  Critics say these facilities are prisons for the organisms