Chapter 11: Endangered

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Chapter 11 Endangered Threatened Species

• April 10, 2007

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Why be concerned with extinction?

• Two categories of values that can be associated
  with any organism
• 1. The values of that organism to (1)
• Ex. medicinal, technological, recreational, etc.
• 2. The values of that organism that do not relate
  to humans
• Ex. are not normally seen or used by humans

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Of importance to humans Some examples

• Rosy periwinkle endangered plant of Madagascar
  used to treat Leukemia Hodgkins disease
• Penicillin derived from a mold overuse has
  decreased its power

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Other examples of useful organisms

• Bison low-fat meat source useful for improving
  grazing conditions
• Whooping Crane Attract tourists in places like
  Texas, which in turn brings money into the
  community

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Aesthetics

• Many organisms are important from an aesthetic
  viewpoint (e.g., watchable wildlife)
• (2) is often cited as one of the most popular
  hobbies in the United States

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Moral connection

• An appreciation for life also appears to foster a
  respect moral responsibility for all life
• There are exceptions to all life (bacteria?)
• Aldo Leopold summarized this as a Land Ethic
  In short, a land ethic changes the role of Homo
  sapiens from conqueror of the land-community to
  plain member and citizen of it. It implies
  respect for his fellow members, and also respect
  for the community as such.

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Endangered Species Legislation

• Legislation in the U.S. did not really start
  until the 1960s
• 1964 1st list of species threatened with
  extinction
• 1966 Endangered Species Preservation Act few
  protective guidelines
• 1969 Endangered Species Conservation Act
  included worldwide species, but still lacked
  protective guidelines
• 1973 Current Endangered Species Act became
  federal law

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Endangered Species Act (ESA)

• Includes substantial criminal fines penalties
  for violations
• Lists species as endangered or threatened
  outlines specific measures for their protection
  restoration
• Secretaries of Interior Commerce list species,
  but the public can also make nominations

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Endangered vs. Threatened

• Endangered in danger of becoming extinct
  throughout all or a portion of its range
• Threatened is likely to become endangered
  throughout all or a portion of its range
• This allows for the listing of populations that
  face local extinction, even though species may be
  abundant in other parts of range

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International Species

• Over half of species on list are foreign (567 are
  foreign)
• Migratory animals that inhabit the U.S. part of
  the year may receive high priority

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Species in U.S.
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Californias Federally Species

• (308 total organisms) 84 animals are FE 40
  animals are FT 1 species is FPT (Killer whale)
  1 species is FPD (Bald Eagle)
• Only Hawaii has more Federally listed species
  than CA next highest is Alabama (117 species)
  fewest is North Dakota, with 9 listed species
• Why does Hawaii have so many listed species? Why
  is CA so high on the list?

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Californias State listed Species

• 47 animal species are state-listed as endangered
  32 are threatened one species is proposed for
  state delisting (Siskiyou Mountains Salamander)

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Goal of list

• The ultimate goal of the ESA is to remove species
  from the list due to population recovery, and
  this is the same for state lists
• Federal examples of recovering species (not
  necessarily de-listed) Aleutian Canada Goose,
  Bald Eagle, Whooping Crane, red wolf, Houston toad

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Causes of extinction/endangerment of populations

• There can be dozens of causes habitat
  alteration, toxins in area, competition with
  exotic/introduced species, etc.
• The single most important cause of extinction or
  endangerment is habitat destruction

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Influence of introduced organisms

• European Starlings House Sparrows in U.S.
• Cats rats on many islands
• Cane toads in Australia

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Influence of pollution

• Brown Pelicans, Bald Eagles, and Peregrine
  Falcons were victims of biological amplification
  brought about by DDT use

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Uncontrolled harvest

• Can be uncontrolled commercial harvest, or
  illegal harvest
• Dodo extinct due to hunting and introduced
  animals
• Passenger Pigeons overharvested
• Eggs of paddlefish used for caviar
• Bison slaughtered in 1800s exclusively for their
  hides

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Ultimate goal of preserving species Biodiversity

• Maximizing biodiversity involves maximizing the
  number of species in an area (within natural
  limits)
• Species that illustrate the health of an
  ecosystem are called indicator species when
  these species are abundant, the ecosystem is
  generally regarded as healthy

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Maintaining an ecosystem

• Rather than trying to discourage use of an
  ecosystem by humans in an effort to preserve that
  ecosystem, we should strive for sustainable use
  of the ecosystem
• A great California example is Mono Lake water
  flowing into this lake is diverted to L.A. The
  lake is one of the most active ecosystems in the
  country, but it has suffered because of this
  diversion and overuse by humans

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Mono Lake
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Protective efforts by private organizations

• Land may be purchased and managed by any of a
  number of well-known groups
• The Nature Conservancy (www.tnc.org)
• The Sierra Club (www.sierraclub.org)
• National Audubon Society (www.audubon.org)
• National Wildlife Society (www.wildlife.org)
• The Wilderness Society (www.wilderness.org)

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Feeding adaptations of birds
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Bill structure

• A birds () is its key adaptation for feeding
• Avian bills are not () birds can flex or bend
  the upper half of the bill
• Like other parts of their skeleton, bird bills
  are usually lightweight, reinforced by internal
  struts, quite strong

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Specialized bill Filter-feeding Flamingos

• Size of filtering apparatus determines a
  flamingos diet
• Greater Flamingos have coarse filters that filter
  out small invertebrates Lesser Flamingos have
  finer filters and can strain out smaller organisms

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Specialized bill Seed-cracking finches

• Husking speed depends on relationship of bill
  size strength to seed size hardness
• Small bills are better at dealing with small
  seeds
• Finches rely on using a small groove in their
  bill and a mobile tongue for cracking seeds

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Bills of nectar-feeding birds

• Bill shapes tend to match the lengths
  curvatures of preferred flowers, which, in turn,
  depend on the birds for pollination

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Bird tongues

• Usually are not () structures, but operate by
  means of bony extensions, called the hyoid
  apparatus
• Hummingbirds woodpeckers have incredibly long
  hyoidal extensions that actually wrap over the
  top of the skull insert in a nostril (this
  allows for a tongue that can be extended more
  than normal)

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Specialized tongues woodpeckers
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How well food is digested

• Hummingbirds assimilate 97 99 of energy in
  their nectar
• Raptors assimilate 66 88 of energy ingested as
  meat fish
• Herbivores assimilate just 30 70 of energy
  from foliage, depending on whether the foliage is
  mature or young

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Innovation use of tools in birds

• Several species use tools to gather food
• Woodpecker Finch uses stick or cactus spine
• Egyptian Vultures crack eggs with stones
• Green Herons use pieces of bread as fishing bait

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Innovation tool use

• Mid-1950s Great Tits in British Isles learned to
  rip open milk bottle caps to drink the cream
• Behavior passed on to other individuals
• Milk companies tried to solve this problem by
  replacing cardboard tops with aluminum ones
  birds learned to open these as well

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Food Caching

• Caching food hiding food for future use
• One way of preparing for food shortages, such as
  those that occur in winter
• Acorn Woodpeckers build large granaries for
  winter, and these granaries are defended from
  other birds

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Food Caching

• Shrikes are notorious for impaling their prey,
  perhaps to allow toxic insects to detoxify, or
  just to store excess prey

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How often is cached food recovered?

• Birds may have hundreds, if not thousands, of
  cache sites
• Many are remembered, but some are not (some seeds
  are planted as a result)
• Western Scrub Jays actually can remember what
  other individuals were watching them cache food
  and may move food once that individual has left