SUSTAINING WILD SPECIES

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CHAPTER 18

• SUSTAINING WILD SPECIES

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The Passenger Pigeon gone forever

• Reasons for extinction of species
• uncontrolled commercial hunting
• lost of habitat and food supply
• Passenger pigeon hunting was big business
• Last pigeon was shot in 1990
• All species will eventually become extinct -
• but human activity -- premature extinctions

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The Rise and Fall of SpeciesWhat are endangered
threatened species?

• Local extinction - organism is no longer in a
  specific area - but exists elsewhere
• Ecological extinction - low numbers -- inability
  to fill ecological role
• Biological extinction - species is no longer
  found anywhere on earth
• Endangered species - could become extinct
• Threatened species could become endangered

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Characteristics of vulnerable species

• K-strategist characteristics
• Limited habitat
• Small population size low density
• Large body size
• Specialized niche
• Low reproductive rate
• Other characteristics
• fixed migrations, top of food chain, high
  economic value to man

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Numbers of threatened species

• Estimates by IUCC and WWF - probably low
  estimates - (notice which are highest, etc.,
  but dont attempt to memorize list)
• Species whose numbers are diminished locally are
  indicators of condition of ecosystem as a whole -
  these are the indicator species

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Reasons for saving wild species

• Important scientific, ecological, economic,
  medical, aesthetic and recreational value
• Provides knowledge of evolution
• Provide ecological services
• Wild strains needed for domesticated strains
• Pollination
• Economic benefits from products

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Reasons for saving wild species - 2

• Plant-based medicines in developing areas and in
  developed countries (including anti- cancer drugs
• Wild organisms provide beauty, etc.
• Ecotourism benefits travel industry
• Ethical importance - range of views from every
  species has a right to exist without human
  interference to Some are needed, but others
  are

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Background vs. Mass extinctions

• Background is natural rate of extinctions
• Mass extinction is catastrophic and widespread
  global climate changes wipe out many species
• Fossil evidence shows 5 great mass extinctions
• Each extinction was followed by adaptive
  radiations

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A Mass Extinction Crisis?

• Conservation biologists say that current
  extinction rate is thousands times background
  rate
• Difference between current past mass
  extinctions
• it is occurring in decades rather than ???
• degradation of biologically diverse environment

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Causes of depletion and premature extinctions

• Human population growth
• Failure to value environment and ecological
  services
• Affluence and economic growth -- increased per
  capita resource use
• Human appropriation of earths net primary
  productivity
• Poverty -- cut forests, overgraze fish etc

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Role of habitat loss, degradation fragmentation

• Greatest threat major areas rainforests, coral
  reefs, wetlands, grasslands and waters
• Island species (endemic) highly vulnerable
• Island biogeography extended to parks, etc. which
  become habitat islands
• Habitat fragmentation due to decreases in
  sustainable populations, increases in edge areas,
  barriers limit dispersal

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Deliberately (or accidentally) introduced species

• Nonnative or alien species
• 70 of food comes from nine crops cultivated
  outside of natural ranges
• Biological pollution - introduced species are
  uncontrolled by natural predators, competitors,
  parasites or pathogens
• Established introduced species impossible to
  remove

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Accidentally introduced species

• Examples are
• zebra and quagga mussels
• fire ants from S. America
• brown tree snake entered Guam
• Formosan termite

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Commercial hunting and poaching

• 12 billion/year illegal international trade of
  endangered animals (or parts)
• Organized crime
• Endangered animals bring high prices
• What about elephant protection? Elephant
  populations in protective areas are destroying
  habitat affects other species
• Should ban be lifted?

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Predator and Pest Control

• Extermination of species which compete for human
  food or game Carolina fruit eating parakeet,
  elephants, coyotes, prairie dogs (followed by
  loss of ferret which feeds on prairie dogs

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Exotic pets and decorative plants

• Many animals die for each animal sold
• Animals taken from natural habitat die or dont
  reproduce in natural habitat -- income from
  tourists
• Methods used to capture animals (e.g. tropical
  fish) destroy habitat (e.g. coral reef)

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Climate change and pollution

• Deforestation and accumulation of heat-trapping
  gases will hurt wildlife even in well-managed
  reserves and sanctuaries
• Pesticides and acid deposition
• Ozone depletion -- skin cancers, cataracts,
  impairs immune system

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Over fishing

• 60 of commercially valuable fish are over-fished
  (tragedy of the commons)
• Trawlers with huge nets which kill many species
  other than ones sought destroy habitats -
  largest human-caused disturbance to biosphere
• purse-seine fishing, long-lining, and drift-net
  fishing

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Threats to Aquatic life - how serious?

• Greatest danger is to fresh water species
  especially near Europe and Asia
• Major causes of decline
• habitat loss degradation (disruption of rivers)
• nonnative species invasions
• over-harvesting - commercial
• Marine losses over-fishing, coral reef
  destruction, dolphin seal mangrove loss,
  toxic red tides and sedimentation

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Protection of wildlife and diversity

• Three basic approaches emphasize
• ecosystems
• preserve balanced populations, establish
  wilderness areas and reserves, reduce nonnatives
• species
• identify species and give legal protection,
  preserve their habitats propagate in captivity
  and return to native habitats
• wildlife management
• regulate hunting, establish harvest quotas,
  develop population management plans,
  international treaties

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International treaties and laws

• Convention on International Trade in Endangered
  Species - 1975 - 145 nations signed protecting
  700 species enforcement is spotty and fines are
  small
• U.S. import and export laws Lacey Act (1900) and
  Endangered Species Act (1973, 1982, 1988) -
  federal agencies cannot fund projects which
  jeopardize listed species

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International treaties and laws -2

• Critical habitat protection
• Limitation of entry ports
• Habitat conservation plans - compromise amendment
  benefiting landowners
• Safe harbor agreements provides technical help
  from conservation agencies
• Candidate conservation agreements - help with
  preservation of declining species

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Should Endangered Species Act be weakened or
strengthened?

• Opponents say act causes economic loss - they are
  trying to weaken the laws (5 ways) - such as
  giving landowners more options and giving them
  compensations
• Conservationists say act addresses economic
  concerns new system to protect and sustain
  biological diversity is needed - identify species
  and ecosystems protect those in danger and
  provide to landowners

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Should all endangered species be protected?

• Maybe concentrate on those with best chance for
  survival, have most ecological value, and are
  potentially useful
• But do we know enough to make these value
  judgements?
• Protection of some species puts others at risk,
  e.g. lions and sea lions

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Wildlife refuges and other protected areas

• 1903 - President Theodore Roosevelt - 1st U.S.
  federal wildlife refuge
• Now 508 refuges - most are wetlands for migratory
  waterfowl
• Conservation biologists want more
• No guidelines for management of National Wildlife
  Refuge system --abuses occur, e.g. Arctic
  National Wildlife Refuge

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Gene banks, botanical gardens, zoos

• How to preserve endangered species
• Gene and seed banks preserve genetic information
• Botanical gardens and arboreta
• Captive breeding programs egg pulling,
  artificial insemination, surgical implantation
  cross fostering
• Zoos and research centers - critical mass
  required to maintain biological evolution

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Wildlife Management

• Manipulating wildlife populations and their
  habitats for their welfare and for human benefit
• Supported by hunting and fishing licenses and
  sometimes state income taxes
• How to decide what is preserved where
• Ecologists want to save biodiversity
• Wildlife conservationists - save specific species

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Wildlife Management -2

• After goals are set - then a management plan
  based upon
• ecological succession
• wildlife population dynamics
• an understanding of the habitat requirements
• How to manipulate vegetation and water supplies -
  control ecological succession
• Wildlife species early, mid-, late successional
  species

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Wildlife Management -3

• Wildlife species are categorized based upon what
  type of habitat they prefer
• early successional species
• midsuccessional species
• late successional species
• wilderness species
• Manage habitat to encourage habitation of desired
  species

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Sport hunting and wildlife management

• Licensed hunters are permitted to hunt in
  designated areas at designated times w/ bag
  limits
• Proponents say hunting keeps populations within
  manageable limits, provides recreation and
  benefits economy
• Opponents say populations would be controlled if
  natural predators were not killed

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Management of migratory waterfowl

• Flyways are migratory routes - often protected by
  treaties
• Populations managed by hunting restrictions,
  habitat maintenance
• Migratory Bird Hunting and Conservation Stamp Act
  of 1934 - duck stamp sales provide for purchase
  of land and easements for habitats

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Fishery Managementmarine biodiversity protection

• Develop commercial and sport fish species
• Reduce populations of less desirable species
• Regulate fishing seasons and catch size
• Create and/or maintain habitats encourage health
  of desired species

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Fishery Managementmarine biodiversity
protection-2

• Exclusive economic zones - offshore fishing zone
  - foreign fishers may fish only with countrys
  permission and catch is limited
• High seas - ocean more than 370 kilometers from
  any country - limits set by international
  maritime law
• Overfishing is a problem - unsustainable
• What are 4 suggestions to control it?
• Why is it difficult to protect marine
  biodiversity?

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The Whaling Industry

• An example of the tragedy of the commons
• Two groups baleen and toothed whales
• feeding differences
• easily killed why are they killed?
• Slowly renewable resource - Why?
• How to manage the populations - International
  Whaling Commission
• Should the ban be lifted? Why? Why not?

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