Threatened, Endangered, and Extinct Species

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Threatened, Endangered, and Extinct Species

• Chapter 7
• Lesson 7.3

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PA Academic Standards for Environment Ecology

• Standard 4.7.10.C
• Identify and explain why adaptations can lead to
  specialization.
• Explain factors that could lead to a species
  increase or decrease.
• Explain how management practices may influence
  the success of specific species.
• Identify and explain criteria used by scientists
  for categorizing organisms as threatened,
  endangered or extinct.

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Learning Objectives

• Students will explain factors that could lead to
  a species increase or decrease.
• Students will explain how management practices
  may influence the success of specific species.
• Students will identify and explain criteria used
  by scientists for categorizing organisms as
  threatened, endangered, or extinct.

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Theme Outline

• Lesson 7.3
• Survival of the Fittest
• Human Impacts on Some Pennsylvania Species
• Threatened, Endangered, and Extinct Species
• Factors That Make Some Species More Prone to
  Extinction
• Help for Threatened and Endangered Species

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Survival of the Fittest

• Seen best through the eyes of Charles Darwin who
  formed the foundation for what we know about
  biodiversity and evolutionary biology.

Charles Darwin

• English Naturalist
• 18091882
• Cartography Expedition
• H.M.S. Beagle
• 1831-1836
• Galapagos Islands
• Variation among plants and animals first
  observed and recorded

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Voyage of the H.M.S. Beagle
Darwin said
populations of organisms over time change in
response to the needs placed on them by the
natural environment in which they live.
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Natural Selection

• Definition process that makes it more likely
  that organisms with the best characteristics for
  survival in a specific environment will survive,
  reproduce, and pass on their advantageous genetic
  traits to offspring

• What is natural selection?
• Organisms produce more offspring than can
  survive to
• reproduce.
• Their offspring vary slightly.
• Characteristics can be passed on from generation
  to
• generation.
• Those most suited to their environment survive
  at the expense
• of those less 'fit'.

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Conditions necessary for natural selection to
occur

• The potential adaptation in question must be a
  trait that varies within a species.
• The adaptation must be one that parents can
  passed on to their offspring genetically.
• One version of the adaptation must benefit the
  members that have it in a way that lets them
  survive and reproduce more than individuals who
  do not have the adaptation.

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Human Impacts on Some Pennsylvania Species

• Natural selection plays a large role in
  maintaining Earths biodiversity by stocking
  populations with individuals that are most likely
  to survive in a particular environment.
• In other words, Mother Nature will take care
  of itself. Because variations exist, certain
  individuals within a species are usually able to
  adapt to environmental changes. However, if the
  environment is altered too much or too fast, even
  the most fit organisms may have difficulty
  adjusting.

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Human Impacts

• Negative Impacts
• Habitat Destruction
• Pollution
• (Water, Land, Air)

• Positive Impacts
• Habitat Restoration

Habitat quality improved Species
survives/recovers
Species displaced or killed
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How can we maintain biodiversity?

• Protect entire ecosystems
• Protect specific species
• Manage game species

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Maintaining biodiversity

• Protect entire ecosystems.
• More than 90 million acres in 450 individual
  refuges have been protected.
• First wildlife refuge established in Florida in
  1903 to protect the brown pelican population.

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Maintaining biodiversity

• Protect specific species.
• Protect habitat that is critical to species
  survival
• Captive breeding and reintroduction programs.
• Example California Condor, Peregrine Falcon,
  Osprey

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Maintaining biodiversity

• Manage game species.
• Ensure that game species populations remain
  fairly stable.
• Example. Deer Bear populations in PA

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Threatened, Endangered, and Extinct Species

• What happens when ecosystems fail and
  alternations in ecosystems are too much for
  species to handle?
• Classification of organisms in danger
• Threatened
• Endangered
• Extinct

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Pennsylvania Biological Survey (PABS)

• Who are they?
• Group of scientists, state and federal agency
  representatives, natural history museums,
  interested citizens.
• What do they do?
• Help maintain Pennsylvanias biodiversity by
  tracking and monitoring many plant and animals
  species, including species of concern.

• Coordinate surveys and research on Pennsylvania
  wildlife.
• Produce publications designed to target public
  audiences
• and focus on species conservation.
• Example 1985, Species of Special Concern in
  Pennsylvania

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Endangered Species Act (ESA)

• U.S. law passed in 1973.
• Governs the protection of species whose
  populations are in decline or could be in danger
  of extinction.
• Forbids the hunting, killing, collecting, or
  harming of species listed as endangered or
  threatened.
• Forbids federal funding of projects that would
  threaten a species.

ESA Categories of Classification

• Threatened
• Endangered
• Extinct

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Threatened Species

• Definition species whose numbers are dwindling
  to a point at which the species could become
  endangered

Rough Green Snake
Red-Bellied Turtle
Osprey
Showy Ladies Slipper
Bald Eagle
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Endangered Species

• Definition species that has so few individuals
  remaining that extinction is a possibility in the
  near future

Delmarva Fox Squirrel
Indiana Bat
Short Eared Owl
Eastern Massasauga
Atlantic Sturgeon
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Extinct Species

• Definition species that no longer exists

Passenger Pigeon
Eastern Elk
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Factors that increase the chance of extinction

• Specific food requirements
• Specific habitat or nesting requirements
• High on food chains or food webs
• Migration
• Reproduces at a low rate
• Limited Habitat Range
• Interference with human activities

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Specific food requirements

• Why is this a problem for some organisms?
• Some species eat very few foods. If habitat
  destruction or pollution destroys these food
  sources, populations can become vulnerable.

Koala
Snail Kite
Panda
Bamboo
Eucalyptus
Apple Snails
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Specific habitat or nesting requirements

• Why is this a problem for some organisms?
• Some species live in only one area or type of
  area.

Spotted Owl
Kirtlands warbler
Tiger Salamander
Fish-less ponds
Old growth forests Pacific Northwest
Jack pine trees, 6-15 yrs old
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Specific habitat or nesting requirements

• Why is this a problem for some organisms?
• Some species high on the food chain are
  vulnerable to problems, such as bioaccumulation.

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Specific habitat or nesting requirements

• Why is this a problem for some organisms?
• Species that migrate must depend on multiple
  habitats and are more vulnerable to environmental
  changes.

Snow Geese
Monarch Butterfly
Hoary Bat
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Reproduction at lower rates

• Why is this a problem for some organisms?
• Some species have very few offspring when they
  reproduce. Populations grow slowly and recovery
  times are much longer than other species.

Giant Panda
Elephant
Sharks
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Interference with human activities

• Why is this a problem for some organisms?
• Some species have been killed, hunted, or
  poisoned by humans because they ruin crops, kill
  livestock, or have somehow become a nuisance.

Grey Wolves
American Alligator
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So what can be done to help?

• Who is in charge?
• National Marine Fisheries Service
• U.S. Fish and Wildlife Service
• What do they do?
• Propose which species get added to and removed
  from the ESA listings.

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How fast is all this happening?

• Estimations are that extinction rates are 1,000
  to 10,000 times their natural rate.
• Limited Success.
• About 40 of the species listed under ESA
  protection have stabilized or improved.
• What about the other 60 of species listed?

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