Sustaining Biodiversity: The Species Approach

1
Chapter 11

• Sustaining Biodiversity The Species Approach

2
Core Case Study The Passenger Pigeon - Gone
Forever

• Once the most numerous bird on earth.
• In 1858, Passenger Pigeon hunting became a big
  business.
• Habitat loss forests cleared
• Hunters catch one pigeon lure others
• Feathers pillows, bones fertilizer, meat
  food
• By 1900 they became extinct from over-harvest and
  habitat loss.
• Females laid one egg per year
• Last wild bird shot in 1900

Figure 11-1
3
SPECIES EXTINCTION

• Species can become extinct
• Locally A species population is no longer found
  in an area it once inhabited but is still found
  elsewhere in the world.
• Ecologically Occurs when so few members of a
  species are left they no longer play its
  ecological role.
• Globally (biologically) Species is no longer
  found on the earth. (forever)

4
Global Extinction

• Some animals have become prematurely extinct
  because of human activities.

Figure 11-2
5
Endangered and Threatened Species Ecological
Smoke Alarms

• Endangered species so few individual survivors
  that it could soon become extinct.
• Threatened species still abundant in its natural
  range but is likely to become endangered in the
  near future.

6
The first species to go tend to be the big, the
slow and the tasty ones those whose valuable
parts can be sold.
Fig. 11-3, p. 224
7
SPECIES EXTINCTION

• Some species have characteristics that make them
  vulnerable to ecological and biological
  extinction.

Figure 11-4
8
SPECIES EXTINCTION
9
SPECIES EXTINCTION

• Biologists use measurements and models to
  estimate extinction rates.
• Background extinction, mass extinctions, and mass
  depletions account for a loss of 99.9 of all
  species that have ever existed.
• Extinction spasm describes the loss of a large
  number of species within a few centuries.
• Predicting extinctions is always difficult
  because of three factors.
• Usually takes a long time , so is difficult to
  document/prove.
• Only a small percent of the worlds species have
  even been identified.
• We know very little about most of the worlds
  identified species.

10
SPECIES EXTINCTION

• Various methods are used to estimate extinction
  rates
• Study past records
• Current Scientific data (IUCN Redlist)
• Base-line info on change in biodiversity over
  time
• Species-area curves
• When 90 of an area is lost, 50 species are
  extinct
• Predicting population sizes, measure habitat
  changes/availability and species interactions

Figure 2. Global Living Planet Index, 1970-2005
The Living Planet Index measures population size
of hundreds of species, to determine a global
trend in biodiversity. It has declined 27 percent
from 1970 to 2005. Source WWF, 2008
11
SPECIES EXTINCTION

• Scientists use measurements and models to
  estimate extinction rates.
• The International Union for the Conservation of
  Nature and Natural Resources (IUCN) publishes an
  annual Red List, listing the worlds threatened
  species.
• The 2004 Red List contains 15,589 species at risk
  for extinction.

12

• Lower Risk (LR) was a catch-all category which
  includes common species as well as those for
  which there may be conservation concern, but
  which do not warrant a higher category. Category
  was removed , promoting its subcategories to full
  categories.
• LR/cd (Conservation Dependent) stable and sizable
  populations depend on sustained conservation
  activity.
• NT (Near Threatened, formerly LR/nt), close to
  qualifying for listing as Vulnerable but not
  fully meeting those criteria slowly declining or
  fairly small populations but probably no danger
  of going extinct even without conservation
  activity in the foreseeable future, or threats
  suspected to affect taxon in the near future but
  still avoidable.
• LC (Least Concern, formally LR/lc), species that
  have been evaluated and found to be so common
  that no conservation concern is projected in the
  foreseeable future.
• Examples LR/cd Coast Redwood LR/nt Bigcone
  Douglas-fir LR/lc Leopard (the species as a
  whole), Orca, House Sparrow.
• Vulnerable (VU) faces a considerable risk of
  extinction in the medium term.
• Examples Ring-tailed Lemur, Great White
  Shark, Royal Poinciana.
• Endangered (EN) faces a high risk of extinction
  in the near future.
• Examples Blue Whale, Desert Bighorn Sheep, Giant
  Panda, Black-footed ferret 
• Critically Endangered (CR) faces an extremely
  high risk of extinction in the immediate future.
• Examples Slender-billed Curlew, Spanish
  Lynx, Red Wolf.
• Extinct in the Wild (EW) captive individuals
  survive, and/or the species has been reintroduced
  outside its former natural range, but the species
  otherwise matches the criteria for "Extinct",
  such that no free-living, natural population is
  believed to exist. "Extirpated" is a term used
  for localized extinctions of extant species it
  always refers to a specific area where the
  species no longer exists.
• Examples Hawaiian Crow, Scimitar Oryx.
• Extinct (EX) extensive and appropriate surveys
  have failed to record any living members.
• Examples Thylacine, Dodo, Huia.
• Data Deficient (DD) a taxon is listed as Data
  deficient when there is inadequate information to
  make an assessment of its risk category,
• Not evaluated (NE) taxa whose conservation
  status has not been assessed to date.

13
Video Penguin Rescue
Videos/penguin_rescue.html

• From ABC News, Biology in the Headlines, 2005 DVD.

14
SPECIES EXTINCTION

• Estimates of future extinction vary due to
  different assumptions about
• total species number
• the proportion found in the tropics
• rate of clearance of tropics
• reliability of methods

15
SPECIES EXTINCTION

• Percentage of various species types threatened
  with premature extinction from human activities.

Figure 11-5
16
SPECIES EXTINCTION

• Scientists use models to estimate the risk of
  particular species becoming extinct or endangered.

Figure 11-6
17
SPECIES EXTINCTION

• Estimates of future extinctions are limited
• Not all species are known or studied
• Total human impact is unclear
• Current rate of extinction 1,000-10,000x rate
  of normal background extinction
• Current model 20 plant species gone by 2030,
  50 by 2099

18
SPECIES EXTINCTION

• Greater than predicted rates are likely
• Exponential population growth
• Biologically diverse hotspots are already
  25-30 loss
• Possible colonization sites are being eliminated,
  degraded and simplified by human activities
• This reduces the rate of speciation SPECIES
  CRISIS

19
IMPORTANCE OF WILD SPECIES

• Wild species have ecologic and economic value
• Causing the premature extinction of species
  eliminates the services they provide.
• Medicine, genetic information, recreational
  value, eco-tourism
• Male lion skin 1,000 living male lion
  515,000 in tourism revenue over 7 years
• Bats insect control, pollination, seed
  dispersal (keystone species)
• INTRINSIC VALUE - an inherent right to exist.
• Some distinguish between the survival rights
  among various types of species (plants vs.
  animals).

20
HABITAT LOSS, DEGRADATION, AND FRAGMENTATION

• The most important causes of premature
  extinction, HIPPO
• Habitat destruction, degradation, and
  fragmentation (greatest threat to species)
• Invasive species
• Population growth
• Pollution
• Overharvest

21
Animation Habitat Loss and Fragmentation
PLAY ANIMATION
22
HABITAT LOSS, DEGRADATION, AND FRAGMENTATION

• The greatest threat to a species is the loss,
  degradation, and fragmentation of where it lives.

Figure 11-7
23
HABITAT LOSS, DEGRADATION, AND FRAGMENTATION

• Tropical deforestation is the greatest species
  eliminator (followed by loss of wetlands and
  plowing grasslands)
• Major Habitat Disturbance
• Agriculture
• Commercial development
• Water development
• Recreation
• Grazing
• Pollution

24
HABITAT LOSS, DEGRADATION, AND FRAGMENTATION

• Endemic species - species found nowhere else on
  earth and are often found in island habitats.
• Habitat islands - habitats surrounded by a
  different one, such as a national park surrounded
  by logging, mining, etc.
• Fragmentation leads to species vulnerability to
  predators, disease, etc.
• Species are limited in their ability to colonize
  new areas, find mates and food.

25
HABITAT LOSS, DEGRADATION, AND FRAGMENTATION

• Reduction in ranges of four wildlife species,
  mostly due to habitat loss and overharvest.

Figure 11-8
26
Indian Tiger
Range 100 years ago
Range today (about 2,300 left)
Fig. 11-8a, p. 230
27
Black Rhino
Range in 1700
Range today (about 3,600 left)
Fig. 11-8b, p. 230
28
African Elephant
Probable range 1600
Range today
Fig. 11-8c, p. 230
29
Asian or Indian Elephant
Former range
Range today (34,00054,000 left)
Fig. 11-8d, p. 230
30
Video Bachelor Pad at the Zoo
PLAY VIDEO

• From ABC News, Biology in the Headlines, 2005 DVD.

31
Case Study A Disturbing Message from the Birds

• Human activities are causing serious declines in
  the populations of many bird species.

Figure 11-9
32
Video Bird Species and Birdsongs
PLAY VIDEO
33
Case Study A Disturbing Message from the Birds

• The majority of the worlds bird species are
  found in South America.
• Threatened with habitat loss and invasive species.

Figure 11-10
34
HABITAT LOSS, DEGRADATION, AND FRAGMENTATION

• 70 of the worlds known species of birds are
  declining.
• One in six species is threatened with extinction
  due to habitat loss and fragmentation.
• Nonnative species are the 2nd greatest threat to
  birds
• Excellent environmental indicators live in every
  climate and biome, respond quickly to
  environmental changes, easy to track and count.
• Birds ecological roles control rodents and
  insects, pollination of flowering plants, seed
  dispersal, and scavengers of dead animals

35
INVASIVE SPECIES

• Many nonnative species provide us with food,
  medicine, and other benefits but a a few can wipe
  out native species, disrupt ecosystems, and cause
  large economic losses.

Kudzu vine was introduced in the southeastern
U.S. to control erosion. It has taken over native
species habitats.
Figure 11-A
36
INVASIVE SPECIES

• Many invasive species have been introduced
  intentionally.

Figure 11-11
37
INVASIVE SPECIES

• They have no natural predators, competitors, or
  pathogens in their new habitat.

Figure 11-11
38
INVASIVE SPECIES

• They can trigger ecological disruptions
• Wild African honeybee displaces natives/impact
  on native plants
• Formosan termite from China swarming,
  aggressive and destructive
• Feral pigs kill livestock, eat crops, spread
  disease, cause erosion to stream banks, spread
  disease to livestock
• Feral cats and domestic cats kill about 568
  million birds per year.

39
INVASIVE SPECIES

• The Argentina fire ant was introduced to Mobile,
  Alabama in 1932 from South America.
• Most probably from ships.
• No natural predators.
• Extremely aggressive
• Eliminated about 90 of native ant species,
• caused widespread agricultural damage
• genetically resistant to pesticides through
  natural selection.

Figure 11-12
40
INVASIVE SPECIES

• Prevention is the best way to reduce threats from
  invasive species, because once they arrive it is
  almost impossible to slow their spread.

Figure 11-13
41
Characteristics of Successful Invader Species
Characteristics of Ecosystems Vulnerable to
Invader Species
Climate similar 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
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
Fig. 11-13, p. 236
42
POPULATION GROWTH, POLLUTION, AND CLIMATE CHANGE

• Population growth, affluenza, and pollution have
  promoted the premature extinction of some
  species.
• Projected climate change threatens a number of
  species with premature extinction.

43
Pollution

• Each year pesticides
• Kill about 1/5th of the U.S. honeybee colonies.
• 67 million birds.
• 6 -14 million fish.
• Threaten 1/5th of the U.S.s endangered and
  threatened species.

Example of biomagnification of DDT in an aquatic
food chain.
Figure 11-15
44
OVEREXPLOITATION

• Smuggling wildlife 3rd largest and most
  profitable illegal cross-border smuggling
  activity after arms and drugs (at least 2/3rds
  die in transit)
• More endangered greater demand
• Removal of many top predators cascade effect
• Killing protected species for their valuable
  parts or selling live to collectors.
• Killing predators and pests that bother us or
  cause economic losses (coyotes, bobcats,
  black-footed ferret).
• Legal and illegal trade in wildlife species used
  as pets or for decorative purposes.

45
OVEREXPLOITATION

• Rhinoceros are often killed for their horns and
  sold illegally on the black market for decorative
  and medicinal purposes.

Figure 11-16
46
OVEREXPLOITATION

• More than 60 bird species, mostly parrots are
  endangered or threatened because of the wild bird
  trade.
• Amphibians, reptiles, mammals and tropical fish
  are also being depleted because of pet trade.
• Ex-poachers in Thailand are now making more money
  taking eco-tourists into the forest than they did
  by poaching hornbills. They also protect these
  birds from poachers.
• Collecting exotic pets and plants (such as
  orchids and cacti) kill large numbers of them and
  endanger these species and others that depend on
  them

47
Case Study Rising Demand for Bushmeat in Africa

• Bushmeat hunting has caused the local extinction
  of many animals in West Africa.
• Can spread disease such as HIV/AIDS and ebola
  virus.

Figure 11-17
48
PROTECTING WILD SPECIES LEGAL AND ECONOMIC
APPROACHES

• International treaties have helped reduce the
  international trade of endangered and threatened
  species, but enforcement is difficult.
• One of the most powerful is the 1975 Convention
  on International Trade of Endangered Species
  (CITES).
• Signed by 169 countries, lists 900 species that
  cannot be commercially traded.
• Difficult to enforce varies from country to
  country

49
PROTECTING WILD SPECIES LEGAL AND ECONOMIC
APPROACHES

• Convention on Biological Diversity (CBD) binds
  governments to reverse the global decline in
  biological biodiversity.
• United States has not ratified this treaty.
• There are no severe penalties or other
  enforcement mechanisms in place.

50

• ESA Endangered Species Act
• Program for the conservation of threatened and
  endangered plants and animals and the habitats in
  which they are found.
• Lead federal agencies the U.S. Fish and Wildlife
  Service (FWS), U.S. National Oceanic and
  Atmospheric Administration (NOAA) Fisheries
  Service.  The FWS maintains a worldwide list of
  endangered species.
• Includes birds, insects, fish, reptiles, mammals,
  crustaceans, flowers, grasses, and trees.
• Prohibits any action that causes a "taking" of
  any listed species of endangered fish or
  wildlife import, export, interstate, and foreign
  commerce of listed species are all generally
  prohibited.

Moderate
High
51
Case Study The U.S. Endangered Species Act

• One of the worlds most far-reaching and
  controversial environmental laws is the 1973 U.S.
  Endangered Species Act (ESA).
• Forbids federal agencies (besides defense
  department) to carry out / fund projects that
  would jeopardize an endangered species.
• Makes it illegal for Americans to engage in
  commerce associated with or hunt / kill / collect
  endangered or threatened species.
• Based on biological facts/protects habitats (HCPs
  inadequate science, many are political
  compromises)

52
The U.S. Endangered Species Act

• Biodiversity hotspots in relation to the largest
  concentrations of rare and potentially endangered
  species in the U.S.
• Political pressure/lack of funds limit (79 of
  plans not implemented)

Figure 11-18
53
Endangered Species

• Because of scarcity of inspectors, probably no
  more than 1/10th of the illegal wildlife trade in
  the U.S. is discovered.

Figure 11-19
54
PROTECTING WILD SPECIES THE SANCTUARY APPROACH

• The U.S. has set aside 544 federal refuges for
  wildlife, but many refuges are suffering from
  environmental degradation.

Pelican Island was the nations first wildlife
refuge.
Figure 11-20
55
PROTECTING WILD SPECIES THE SANCTUARY APPROACH

• Gene banks, botanical gardens and using farms to
  raise threatened species can help prevent
  extinction, but these options lack funding and
  storage space.
• Zoos and aquariums can help protect endangered
  animal species by preserving some individuals
  with the long-term goal of reintroduction, but
  suffer from lack of space and money.
• Many reintroductions fail no suitable habitat,
  not able to survive, renewed overhunting/capture
• Large population is needed to maintain capacity
  for evolution

56
Video Hsing Hsing Dies
PLAY VIDEO

• From ABC News, Biology in the Headlines, 2005 DVD.

57
RECONCILIATION ECOLOGY

• Reconciliation ecology find ways to share
  places we dominate with other species.
• Replacing monoculture grasses with native
  species.
• Maintaining habitats for insect eating bats can
  keep down unwanted insects.
• Reduction and elimination of pesticides to
  protect non-target organisms (such as vital
  insect pollinators).
• Maintain diverse yards with natives/ biodiverse
  gardens/rooftop gardens
• Bluebirds project Golden State Park

58
Using Reconciliation Ecology to Protect Bluebirds

• Putting up bluebird boxes with holes too small
  for (nonnative) competitors in areas where trees
  have been cut down have helped reestablish
  populations.

59
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. Spread the word. Talk to your
friends and relatives about this problem and what
they can do about it. http//tolweb.org/onlinecon
tributors/app?serviceexternal/ViewImageDatasp23
923
Fig. 11-21, p. 246