Sustaining Biodiversity: The Species Approach

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Sustaining Biodiversity The Species Approach

• Chapter 8

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The Passenger Pigeon Gone Forever

• 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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Types of Species Extinction

• Local extinction- like it sounds
• Ecological extinction - too few to play
  ecological role
• Biological extinction - all gone everywhere

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

• Endangered species could soon become extinct
  over some or all of its range
• Threatened species still abundant, but likely to
  become endangered

Fig. 8-3, p. 156
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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)
Black-footed ferret
Symphonia (Madagascar)
Utah prairie dog (threatened)
Ghost bat (Australia)
Black rhinoceros (Africa)
Oahu tree snail
California condor
Black lace cactus
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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
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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
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Problems Estimating Extinction Rates

• Extinction not easily documented over time
• Many species remain unidentified
• Little is known about most identified species

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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

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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

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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 gt .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

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Natures Pharmacy
9 of 10 leading Rx drugs originated from wild
species lt 1 of flowering plants in tropical
forests studied for medicinal properties
Fig. 8-7, p. 158
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Causes of Premature Extinction

• HIPPCO
• Habitat destruction and fragmentation
• Invasive (alien) species
• Population growth (humans)
• Pollution
• Climate Change
• Overharvesting

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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

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Threatened Species of U.S. Songbirds
Spragues pipit
Bichnells thrush
Blacked-capped vireo
Golden-cheeked warbler
Cerulean warbler
Florida scrub jay
California gnatcatcher
Kirtlands warbler
Henslows sparrow
Bachmans warbler
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Reduced Ranges
Asian or Indian Elephant
Indian Tiger
Former range
Range 100 years ago
Range today (34,00054,000 left)
Range today (about 2,300 left)
See Fig. 8-9, p. 161
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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
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Accidentally Introduced Species
Sea lamprey (attached to lake trout)
Argentina fire ant
Eurasian muffle
Brown tree snake
Common pigeon (Rock dove)
Formosan termite
Zebra mussel
Asian long-horned beetle
Asian tiger mosquito
Gypsy moth larvae
Fig. 8-10, p. 163
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Kudzu
Fig. 8-11, p. 164
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Fire Ant Invasion
Currently as far north as CA and the Bay Area
1918
2000
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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

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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
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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 15Kgt 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

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Bushmeat
Fig. 8-17, p. 169
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Extinction Threats from Climate Change and
Pollution

• Greenhouse effect
• Pesticide threats- decline in honeybees, birds
  fish
• DDT biomagnification (bioaccumulation)

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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
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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
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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 worlds 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
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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
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Confiscated Products From Endangered Species
Due to sparse and inspectors, lt 10 of illegal
wildlife trade in US is discovered
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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
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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- Worlds 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

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Endangered Sea Turtles
Worlds 8 major sea turtle species are endangered
or threatened-
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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