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Sustaining Biodiversity: The Species Approach

Sustaining Biodiversity: The Species Approach. Chapter 8. Once most common bird in N. America - Extinct in 1914 Humans were responsible (huge flocks, narrow colonies = easy to kill- stool pigeons) Why they were hunted (food, feathers, fertilizer) Extinction.

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Sustaining Biodiversity: The Species Approach

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  1. Sustaining Biodiversity: The Species Approach Chapter 8

  2. Once most common bird in N. America- Extinct in 1914 Humans were responsible(huge flocks, narrow colonies = easy to kill- stool pigeons) Why they were hunted(food, feathers, fertilizer) Extinction The Passenger Pigeon: Gone Forever

  3. Types of Species Extinction • Local extinction- like it sounds • Ecological extinction - too few to play ecological role • Biological extinction - all gone everywhere

  4. Some Prematurely Extinct Species Passenger pigeon Great auk Dodo Dusky seaside sparrow Aepyornis (Madagascar) Fig. 8-2, p. 154

  5. Endangered speciescould soon become extinct over some or all of its range Threatened speciesstill abundant, but likely to become endangered Endangered and Threatened Species Fig. 8-3, p. 156

  6. More Endangered and Threatened Species Florida manatee Northern spotted owl (threatened) Bannerman's turaco (Africa) Gray wolf Florida panther Devil's hole pupfish Snow leopard (Central Asia) Symphonia (Madagascar) Black-footed ferret Utah prairie dog (threatened) Ghost bat (Australia) Black rhinoceros (Africa) Oahu tree snail California condor Black lace cactus

  7. Characteristics of Extinction-Prone Species Characteristic Examples Low reproductive rate (K-strategist) Blue whale, giant panda, rhinoceros Specialized niche Blue whale, giant panda, Everglades kite Narrow distribution Many island species, elephant seal, desert pupfish Bengal tiger, bald eagle, grizzly bear “The first animal species to go are the big, the slow, the tasty and those with valuable parts such as tusks and skins.”E.O.Wilson Feeds at high trophic level Fixed migratory patterns Blue whale, whooping crane, sea turtles Rare Many island species, African violet, some orchids Commercially valuable Snow leopard, tiger, elephant, rhinoceros, rare plants and birds California condor, grizzly bear, Florida panther Large territories Fig. 8-4, p. 157

  8. Percentages of Various Types of Organisms Threatened with Extinction by Human Activities 34% (51% offreshwater species) Fish 24% Mammals 20% Reptiles 14% Plants Birds 12% Fig. 8-5, p. 157

  9. Problems Estimating Extinction Rates • Extinction not easily documented over time • Many species remain unidentified • Little is known about most identified species

  10. Estimating Extinction Rates • Estimates from records and fossils • Species-area relationship: on average, a 90% habitat loss causes the extinction of 50% of the species living in that habitat • Models to estimate risks of extinction for a particular species • Estimates of extinction rates can vary depending on available data and what assumptions are used

  11. Human Impacts on Extinction Rates • Humans have greatly accelerated extinction rates (1,000 - 10,000x) • Conservative estimates of 0.1% to 1% per year. • Due to human population increases • Extinction rates higher in biodiversity “hot spots” • Speciation crisis (humans limiting long-term recovery of biodiversity via impacts on ecosystems, colonization sites for emergence of new species) • Inadequate estimations of extinction rates • Precautionary strategy

  12. Importance of Wild Species • May take nature 5 million years to replace the species that may be lost in the 21st century • Instrumental value- ecological services, food, fuel, lumber, paper, medicine • Genetic information- better ability to adapt to changing enviro. conditions • Recreational pleasure and ecotourism- lion living in Kenya generates > $.5 million over 7 years elephant worth about $1 million over 60 yrs • Intrinsic or existence value- Do species have an inherent right to exist? • Even small organisms can be important

  13. Nature’s Pharmacy 9 of 10 leading Rx drugs originated from wild species < 1% of flowering plants in tropical forests studied for medicinal properties Fig. 8-7, p. 158

  14. Causes of Premature Extinction • “HIPPCO” • Habitat destruction and fragmentation • Invasive (alien) species • Population growth (humans) • Pollution • Climate Change • Overharvesting

  15. Extinction Threats from Habitat Loss and Degradation • Importance of habitats • Deforestation- particularly tropical forests • Destruction of wetlands and coral reefs • Endemic species- found nowhere else on earth • “Habitat islands”- surrounded by different habitat • Habitat fragmentation - continuous area divided into small, scattered patches • “Message” from the birds - 70% are declining, 1/6 threatened with extinction Birds are indicator species

  16. Threatened Species of U.S. Songbirds Cerulean warbler Sprague’s pipit Bichnell’s thrush Blacked-capped vireo Golden-cheeked warbler Kirtland’s warbler Florida scrub jay California gnatcatcher Henslow’s sparrow Bachman’s warbler

  17. Reduced Ranges Asian or Indian Elephant Indian Tiger Former range Range 100 years ago Range today (34,000–54,000 left) Range today (about 2,300 left) See Fig. 8-9, p. 161

  18. Deliberately Introduced Species Purple looselife European starling African honeybee (“Killer bee”) Nutria Salt cedar (Tamarisk) Marine toad Water hyacinth Japanese beetle Hydrilla European wild boar (Feral pig) Fig. 8-10, p. 163

  19. Accidentally Introduced Species Sea lamprey (attached to lake trout) Argentina fire ant Brown tree snake Eurasian muffle Common pigeon (Rock dove) Formosan termite Zebra mussel Asian long-horned beetle Asian tiger mosquito Gypsy moth larvae Fig. 8-10, p. 163

  20. Kudzu Fig. 8-11, p. 164

  21. Fire Ant Invasion Currently as far north as CA and the Bay Area 1918 2000

  22. Reducing Threats from Nonnative Species • Cost U.S. Taxpayers $137 billion /yr • Threaten 1/2 critical species in US (95% in Hawaii) • Prevention is best • Identify the characteristics of nonnative species • Identify vulnerable ecosystems • Thoroughly inspect imports • Establish appropriate international laws • Discharge of ballast waters from ships

  23. Characteristics of Successful Invader Species and Vulnerable Ecosystems Characteristics of Successful Invader Species Characteristics of Ecosystems Vulnerable to Invader Species • High reproductive rate, short generation time (r-selected species) • Pioneer species • Long lived • High dispersal rate • Release growth- inhibiting chemicals into soil • Generalists • High genetic variability • Similar climate to habitat of invader • Absence of predators on invading species • Early successional systems • Low diversity of native species • Absence of fire • Disturbed by human activities Fig. 8-13, p. 165

  24. Extinction Threats from Poaching • Profits of poachingMt. gorilla = $150K; panda pelt = $100K; chimp = $50K; rhino horn = $28k /Kg(most live animals die in transit) • Causes of poaching: food, fur, pets, traditional medicines, trophies, eliminating pests, etc. • Bushmeat • Illegal pets and decorative plantsorchids can fetch up to $5K; saguaro cactus $15K> 60 bird species are endangered or threatened due to wild bird tradekeeping a bird indoors for more than 10 yrs doubles chances of getting lung cancerIrony of collecting exotics • Attempts to control poaching

  25. Bushmeat Fig. 8-17, p. 169

  26. Extinction Threats from Climate Change and Pollution • Greenhouse effect • Pesticide threats- decline in honeybees, birds & fish • DDT biomagnification (bioaccumulation)

  27. Biomagnification of DDT DDT in fish-eating birds (ospreys) 25 ppm Fat soluble chemicals increase in concentration at higher levels of food web DDT in large fish (needle fish) 2 ppm DDT in small fish (minnows) 0.5 ppm DDT in zooplankton 0.04 ppm DDT in water 0.000003 ppm, or 3 ppt Fig. 8-15, p. 166

  28. Protecting Wild Species International Treaties Convention on International Trade in Endangered Species (CITES)• signed by 166 countries- lists 900 endangered species that cannot be commercially traded• restricts international trade of 29,000 threatened species• limited impact due to spotty enforcement, ability for countries to except themselves Convention on Biological Diversity (CBD)• legally binds governments to reverse decline of biodiversity• ratified by 190 countries (not USA)- No severe penalties

  29. Protecting Wild Species - U.S. Federal LawsImportant on APES Exam Lacey Act (1900)- prohibits transporting live or dead wild animals or parts across state borders w/out federal permit. Endangered Species Act (ESA- 1973)- one of world’s toughest & controversial enviro laws• goal is to identify & protect endangered species in USA & abroad• NMFS / USFWS responsible for identifying and listing endangered & threatened species• illegal for Americans to buy any product made from protected species - • species cannot be killed, collected or injured in US• $100k fines and 1 year prison terms for offenses• protection extended to threatened & endangered foreign species• In 2005 there were1,260 protected species (many critical species not yet listed) Establishing critical habitats- ESA requries protection of critical habitat for recovery of listed species. Due to lack of funds, only 33% of listed species have critical habitat establishedSince 2001, gov has stopped listing new species & designating critical habitats unless mandated by court order

  30. Endangered Species Act (continued) Habitat conservation plans- • 1982 amendment to ESA allows landowners, developers or loggers to destroy critical habitat if they take steps to protect members of species (set asides, paying to relocate, or buying suitable habitat elsewhere• criticized as loophole - many plans approved without scientific evaluation ESA and commercial shipping- all commercial wildlife shipments must leave or enter US via one of nine designated ports• 60 USFWS inspectors examine only 25% of 90,000 yearly shipments• violators often not prosecuted and pay only small fine

  31. Confiscated Products From Endangered Species Due to sparse $$ and inspectors, < 10% of illegal wildlife trade in US is discovered

  32. Biodiversity Hot Spots in the US Top Six Hot Spots 1 Hawaii 2 San Francisco Bay area 3 Southern Appalachians 4 Death Valley 5 Southern California 6 Florida Panhandle 2 4 3 5 6 Concentration of rare species 1 Low Moderate High

  33. Protecting Marine Species • Role of the Endangered Species Act • Threats from litter- plastic threatens millions of marine species “Pacific Garbage Dump” - Nightline Video - click here • Threatened sea mammals- whales, seals, sea lions • Threatened sea turtles- • World’s 8 major sea turtle species are endangered or threatened-•Poaching and threats from fishing nets • Need more knowledge of marine biodiversity • Difficulty enforcing international treaties

  34. Endangered Sea Turtles World’s 8 major sea turtle species are endangered or threatened-

  35. What Can We Do to Protect Species? What Can You Do? Protecting Species • Do not buy furs, ivory products, and other materials made from endangered or threatened animal species. • Do not buy wood and paper products produced by cutting remaining old-growth forests in the tropics. • Do not buy birds, snakes, turtles, tropical fish, and other animals that are taken from the wild. • Do not buy orchids, cacti, and other plants that are taken from the wild. Fig. 8-20, p. 174

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