chapter 22 sustaining wild species
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Chapter 22 Sustaining Wild Species. The Story of Martha. - PowerPoint PPT PresentationTRANSCRIPT
Chapter 22Sustaining Wild Species
The Story of Martha
Oh high above the trees and the reeds like rainbows they landed soft as moonglow in greens and reds they fluttered past the windows ah but nobody cared or saw til the hungry came in crowds with their guns and dozers and soon the peace was over God what were they thinking of? Oh on and on til dreams come true you know a piece of us all goes with you Oh the birds went down they fell and they faded to the dozens Til in a Cincinnati Zoo was the last one Yes all that remained was the last with a name of Martha Very proud, very sad, but very wise Oh as the lines filed by there were few who cared or could be bothered how could anyone have treated you harder and it was all for a dollar or more Oh on and on til dreams come true you know a piece of us all goes with you Oh and surrounded there by some of whom wept around her in a corner of the cage they found her she went as soft as she came so shy til the last song oh the passenger pigeon was gone... John Harold
The last word in ignorance is the person who says of an animal or plant: “What good is it?...If the land mechanism as a whole is good, whether we understand it or not…Harmony with land is like harmony with a friend; you cannot cherish his right hand and chop off his left.
Aldo Leopold
Key Concepts
Human effects on biodiversity
Importance of biodiversity
How human activities affect wildlife
Management of wildlife
22.1 Human Impacts on Biodiversity
A. Factors that increase biodiversity
Physically diverse habitat Small - moderate
environmental disturbances
Evolution
B. Factors that decrease biodiversity
Environmental stress
Large disturbances Extreme conditions Limitation of
essential resources Introduction of alien
species Geographic
Isolation
Endangered Species Program
67%Secure orapparently
secure
1%Other
16%Vulnerable
8%Imperiled
7%Critically imperiled
1% Probably extinct
Fig. 22.4, p. 554Endangered USAEndangered PA
How Serious is a Loss of Biodiversity?
Some argue that the threat is exaggerated…
1. We don’t know how many species there are
2. We don’t know the true value of all species in ecosystems
3. Estimates are based on models that lack data
Should We Focus on Sustaining Species or Ecosystems?
A. Ecosystem Approach Major goal is to assure that
there is enough protected land and water to provide habitat.
B. Species-by-Species Approach Identify most at-risk species Understand the species Focus on protecting them
The Species Approach The Ecosystem Approach
GoalProtect species frompremature extinction
Strategies
• Identify endangered species•Protect their critical habitats
Tactics• Legally protect endangered species
• Manage habitat
• Propagate endangered species in captivity
• Reintroduce species into suitable habitats
Goal
Protect populations ofspecies in their naturalhabitats
StrategyPreserve sufficient areasof habitats in differentbiomes and aquaticsystems
Tactics• Protect habitat areas through private
purchase or government action• Eliminate or reduce populations of
alien species from protected areas• Manage protected areas to sustain
native species• Restore degraded ecosystems
22.2 Three Types of ExtinctionA. Local Extinction:Species is no longer found in an
area it once was, but it is found in other areas
B. Ecological Extinction: So few that it can no longer
play its ecological role
C. Biological Extinction: Species is no longer found
anywhere on the earth Biological Extinction is Forever Irreversible loss of genes
Species Status Classification:
Endangered: So few individual
survivors that the species can become extinct over all or part of its range
Threatened or Vulnerable: Still abundant in its
natural range and may become endangered
Threatened and Endangered Species of Pennsylvania Links: PA GAME COMMISSION PA FISH AND BOAT COMMISSION US FISH AN WILDLIFE SERVICE
Rare Species: Naturally small
populations due to limited geographic range
Locally depleted by human activities
Vulnerable to extinction
East African Bongo(Boocerus eurycerus isaaci
Golden-lion Tamarin(Leontopithecus rosalia)
Characteristic ExamplesLow reproductive rate(K-strategist)
Specialized niche
Narrow distribution
Feeds at high trophic level
Fixed migratory patterns
Rare
Commercially valuable
Large territories
Blue whale, giant panda,rhinocerosBlue whale, giant panda,Everglades kiteMany island species,elephant seal, desert pupfishBengal tiger, bald eagle,grizzly bearBlue whale, whooping crane,sea turtlesMany island species,African violet, some orchidsSnow leopard, tiger, elephant, rhinoceros, rare plants and birdsCalifornia condor, grizzly bear, Florida panther
Types of ExtinctionsA. Background
Extinction- A small,
naturally occurring, low rate of extinction.
One species / million / year
Approximately 10-100 species/year
B. Mass Extinction- • A rise above the background rate, often catastrophic and global.
• Estimated to be five in the past 500 million years
Geological Periods
Millions of years ago
Num
ber o
f fam
ilies
of m
arin
e an
imal
s
Mass extinctions800
600
400
200
0570 505 438 360 286 208 144 65 0
CambrianOrdovician
SilurianDevonian
Carboniferous
PermianTriassic
JurassicCretaceous
TertiaryQuaternary
?
408 245 2
Fig. 22.10, p. 558
Extinction of the Dinosaurs
Today’s Extinction Crisis 27,000 species/yr in the tropical forests Background extinction rate for mammals
(1 per 200 yrs) In past 400 years 89 mammalian
extinctions have occurred, 45 times the predicted rate
169 mammal species are listed as critically endangered
30% of the world's animals and plants could be on a path to extinction within 100 years
http://www.pbs.org/wgbh/evolution/library/03/2/l_032_04.html
Increased Rates of Instinction
22.3 Why Care About Biodiversity?The Earth’s Overall Biodiversity has
2 Types of Value:1. Instrumental Value: Usefulness to humans
2. Intrinsic Value: Because they exist regardless
of their value
Value of Nature
Instrumental Intrinsic
Utilitarian Non-utilitarian
(human centered) (species orecosystemcentered)
GoodsEcological services
Information
Recreation
ExistenceAestheticBequest
Fig. 22.11, p. 561
Instrumental ValuesUtilitarian (Use)
-Economic goods
-Ecological Services
-Information-Recreation
Non-Utilitarian (Nonuse)
-Existence-Aesthetic-Bequest
RauvolfiaSoutheast AsiaTranquilizer, high blood pressure medication
EuropeDigitalis for heart failure
Foxglove
Pacific yewPacific NorthwestOvarian cancer
South AmericaQuinine for malaria treatment
Cinchona
MadagascarHodgkin's disease, lymphocytic leukemia
Rosy periwinkle
Overfishing
Habitatloss
Habitatdegradation
Introducingnonnativespecies
Commercialhunting
andpoaching
Sale ofexotic pets
anddecorative
plants
Predatorand
pest control
Pollution
Climatechange
Basic Causes• Population growth• Rising resource use• No environmental
accounting• Poverty
Fig. 22.13, p. 564
Causes of Premature Extinction
22.4 Causes of Premature Extinction
1. Habitat loss, degradation, and depletion
-In U.S. the major disturbances are…
*agriculture/grazing *development *outdoor recreation *pollution
Habitat Fragmentation –A large, continuous area of habitat is reduced in area and divided into a patchwork of isolated areas.
Rainforest becomes rangeland along Brazils Transamazonia highway.
Three-quarters of the deforestation of the Brazilian Amazon has occurred within 30 miles of a paved highway.
National Geographic Photographer: Maria StenzelLocation: Brazil.
Asian or Indian Elephant
Former rangeRange today(34,000–54,000 left)
Fig. 22.14d, p. 565
Indian Tiger
Range 100 years agoRange today(about 2,300 left)
Fig. 22.14a, p. 565
Black Rhino
Range in 1700Range today(about 2,400 left)
Fig. 22.14b, p. 565
African Elephant
Probable range 1600Range today(600,000 left)
2. Harm by Nonnative Species-U.S. has 50,000 Nonnative species-49% of 1,200 endangered and threatened species are threatened by nonnative species-Nonnative species fall into two categories…
A. Deliberately Introduced
B. Accidentally Introduced
A. Deliberately Introduced -Supply 98% of U.S. food -Can have detrimental
affects without predators, parasites, or competition to control numbers.
KUDZU VINE:
FERAL CATS
B. Accidentally Introduced Many times they are
transported in shipping products
Brown Tree Snake
Fire Ants
1918
Fig. 22.18, p. 570
2000
Expansion of the fire ant in southern states.
Formosia termite
Tiger Mosquito
Characteristics ofSuccessful
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
Characteristics ofEcosystems Vulnerable
to Invader Species
• Similar climate to habitat of invader
• Absence of predators on invading species
• Early successional species
• Low diversity of native species
• Absence of fire
• Disturbed by human activities
-Control of Nonnative species begins with identifying characteristics that allow them to succeed
3. Commercial Hunting/Poaching
-International trade of wild plant and animals is worth $10-$20 billion dollars per year.
-1/4 of total is in illegal salesGorilla - $150,000Chimp - $50,000Rhino Horn - $13,000/lb.Bushmeat - $150 million /yr.
http://cbs5.com/seenon/consumer/bushmeat.africa.illegal.2.453673.html
http://cbs5.com/seenon/consumer/bushmeat.africa.illegal.2.453673.html
Indian police officers display three tiger skins and skeletons they seized in Allahabad on December 4, 2007.
The police said they broke a major poaching ring in northern India this week when they arrested an alleged kingpin and 15 others.
Tiger Pelts
This family of Gorillas was Slaughtered for Bush meat
Orphans of the Slaughter
Gorilla Hand: A Delicacy
Grisly Wildlife Trade Exposed
Poachers Use a Chain Saw to Remove a Rhino Horn
Rhino Poaching
Elephant Poaching
Ivory Trade
Profiting from Safaris
A Controversial Management Practice
POACHING A CHICKEN
4. Exotic Pets
-25 Million U.S. households have exotic birds
-Leads to a loss of Ecotourism
-Use of Cyanide to capture tropical fish
-Orchids and Cacti for decoration
5. Climate Change and Pollution -Increase in global warming -Introduction of
pesticides/herbicides, etc.
6. Loss of Genetic Diversity -Decreased ability to reproduce and
adapt to changing conditions
Founder Effect InbreedingGenetic Drift Bottleneck Effect
22.5 Solutions to Protecting Species
A. International Treaties1. CITES (1975 Convention on
International Trade in Endangered Species)
800 species that can’t be traded
29,000 species regulated since they are at risk of becoming threatened
LIMITED SUCCESS for CITES Difficult to enforce Small fines for those
convicted Countries can exempt
themselves Many countries that have not
signed CITES
B. National Laws1. LACEY ACT 1900: Prohibits transport of dead
animals across state lines without a permit
2. ENDANGERED SPECIES ACT: Illegal to import or trade any
product from an endangered or threatened species…
Unless used for scientific purposes
Who Determines What is Protected?
National Marine Fisheries Service:List and identify Ocean Species
U.S. Fish and Wildlife Service:Identify all other endangered
species
* Fines and imprisonment can be imposed to ensure the protection of endangered species
Concentration of rare species
Low Moderate High
Top Six Hot Spots
1 Hawaii2 San Francisco Bay area3 Southern Appalachians4 Death Valley5 Southern California6 Florida Panhandle
4
5
2
6
3
1 Fig. 22.23, p. 575
6 Hotspots for Endangered Species
What Have Land Owners Done to Avoid the ESA?
Some land owners have managed their land so less endangered species use it
Should We Weaken the ESAConcerns about the economic impacts…1. Make protection on private land
voluntary2. Have the gov’t pay for lost land3. Make it harder to list new species4. Give the secretary of the interior
the right to allow a species to become extinct
5. Can allow exemptions to states6. Prohibit public lawsuits
Should the ESA be Strengthened? 0.05% of projects have been
blocked by ESA The act does allow for
economic concerns “God Squad” – any federal
project can be exempted from ESA to prevent economic loss
Government will bargain with HCP’s
Habitat Conservation Plans (HCP) Used as a compromise between
the interests of land owners and the threatened species
Owners are allowed to destroy some habitat or endangered species on private land…
In exchange for taking measures to protect the species
Protective Measures of HCP’s Set aside a part of the
habitat as a preserve Pay to relocate to a suitable
habitat Pay the government to buy
suitable habitat elsewhere.
What are the concerns with this type of plan?
Removing Barriers of ProtectionSafe Harbor Agreement: Land owners voluntarily
restore habitat on their land
Candidate Conservation Agreement:
Landowners volunteer to take steps to help declining populations not yet listed
Fig. 22.24, p. 576
Should We Try to Protect all Species?
Can’t possibly save all Focus on…1. Most likely to succeed2. Ones with the greatest
amount of ecological value3. The most useful in medicine* FOCUS ON KEYSTONE
SPECIES