Transcript Biodiversity & Fragile Ecosystems

Chapter 9
Sustaining Biodiversity:
The Species Approach

The Passenger Pigeon





James Audubon once saw a flock fly over him
for 3 straight days! (1813)
Was once the most numerous bird species on
earth
Have been extinct in the wild since 1900. The
last pigeon died in 1914 in the Cincinnati Zoo
Uncontrolled commercial hunting and habitat
loss- good to eat, feathers used in pillows, easy
to kill
Stool pigeon - a way to attract birds
Losses in Biodiversity
Extinction – loss of species; some is natural; if
species doesn’t adapt, will die out
 5 major extinctions:





Ordovician
Devonian
Permian
Triassic
Cretaceous – 65 mya; 70% of all species
The rate at which species are now
disappearing is at least 1000 times faster
than ever before.
If the present trends continue, it is
estimated that between 22-47% of all
known plant species could be extinct in
the next 50 years.
I
Golden Toad of Costa Rica, Extinct
Golden Toads



Lived in 4 sq km of high altitude cloud forest
in Costa Rica (Monteverde)
First described in 1966
Has not been seen since 1989
Possible reasons for extinction


The fungus chytrid
Too many dry days





Climate change and El Nino
Very small range
Heavy dependence on moisture
Because they have sensitive moist skin, frogs
and toads are also especially vulnerable to
pollution and ultraviolet radiation.
Deforestation
Extinction Can Affect One Species or Many
Species at a Time

Background extinction – continuous low level
1-5 species becomes extinct for every 1 million
species each year. (0.0001%)




1 per million= 1/1,000,000 = 0.000001 species per
year
As a percent, 0.000001 X 100 = 0.0001%
Extinction rate – percentage of species that go
extinct within a time period
Today’s extinction rate could be 0.01%- 0.1% if we
are losing species 1,000 times faster than ever. We
could be losing 14,000 species a year if there are 14
million species
Mass extinction: loss of many species in a short period of
time
(Permian-Triassic Extinction- lost 95%
of all species)
Levels of species extinctionLocal extinction – one area but found elsewhere
Ecological extinction – no longer occupies
niche
Biological extinction – completely gone
Dodo- extinct in 1681
Causes of extinction:
1. Natural causes – volcano, sea level,
change in climate, new predator, disease
2. Human causes –
 Habitat destruction – 50%
 Pollution – 16%, DDT, oil spills
 Hunting/selling – 18%
 Introduced species – 16%, kudzu
Habitat Loss Is the
Greatest Threat to Species

Habitat destruction, degradation, and
fragmentation *(deforestation of tropical rain
forests is the #1 cause)





Invasive (nonnative) species
Population and resource use growth
Pollution
Climate change
Overexploitation
Introduced Species

Aka exotic; alien
Table of terms related to "Introduced Species"
NATIVE
INDIGENOUS
or ENDEMIC
NON-NATIVE
INTRODUCED (broad definition)
CULTIVATED
and
LIVESTOCK
Established in the wild
INTRODUCED
(narrow definition)
INVASIVE
(pest)
All others
not listed*
*Not listed in any "official" source as a pest species
Characteristics of Invader Species and
Ecosystems Vulnerable to Invading Species
Some Deliberately Introduced Species
Can Disrupt Ecosystems

Many species introductions are beneficial





Food
Shelter
Medicine
Aesthetic enjoyment
Nonnative species may have no natural




Predators
Competitors
Parasites
Pathogens
Some Harmful
Nonnative
Species
in the United
States
Illegal Killing, Capturing, and Selling of
Wild Species Threatens Biodiversity

Poaching and smuggling of animals and
plants




Animal parts
Pets
Plants for landscaping and enjoyment
Prevention: research and education
White Rhinoceros Killed by a Poacher
ENDANGERED SPECIES


Endangered species –
population is declining to
very low levels; if
continues will go extinct
Threatened species –
population is declining
rapidly because of
human impacts
Endangered
Natural Capital:
Species
Threatened with
Premature
Extinction
Endangered Species


Often we try to protect “charismatic megafauna” but
many others in danger too.
US examples:













Sea turtles (hawksbill, Kemp’s Ridley, loggerhead)
Gray wolf
Florida manatee
Ivory-billed woodpecker
Green pitcher plant
Grizzly bear
Stellar sea lion
Virginia big eared bat
California condor
Gila trout
American crocodile
White Bladder pod
Karner blue butterfly
Characteristics of Species That Are Prone to
Ecological and Biological Extinction
International Treaties Help to Protect Species

1975: Convention on International Trade in
Endangered Species (CITES)




Signed by 172 countries
Bans hunting, capturing and selling of T&E species
Has helped reduce international trade, but
enforcement varies from country to country
Convention on Biological Diversity (CBD)




Focuses on ecosystems
Prevent /control spread of harmful invasives
Ratified by 190 countries (not the U.S.)
No severe penalties or enforcement measures
Confiscated Products Made from
Endangered Species
Endangered Species Act (ESA): 1973 and
amended in 1982, 1983, and 1985






U.S. Fish & Wildlife Service keeps list of all threatened
and endangered species.
Threatened or endangered animals may not be caught or
killed.
Threatened or endangered plants may not be disturbed
Threatened or endangered species and products made
from them may not be bought or sold.
The federal government may not construct any project
that jeopardizes endangered species. (Tellico Dam, TN)
The Fish & Wildlife Service must prepare a species
recovery plan for each threatened or endangered species.
ESA- one of the most far-reaching
environmental law ever adopted





Species listed only when serious danger of
extinction
Takes decades for most species to become
endangered or extinct
More than half of the species listed are stable or
improving
Budget has been small
Suggested changes to ESA



Increase the budget
Develop recovery plans more quickly
Establish a core of the endangered organism’s
survival habitat
Problems with ESA




Difficult to get species on endangered list.
Habitat may be destroyed before it’s studied.
Focuses on individuals not ecosystems.
Controversial



Northern Rocky Mountain wolf population –
delisted (includes Montana, Idaho, Wyoming)
30 breeding pair goal was reached
Now, wolves can be shot if seen “attacking or
molesting” domestic animals.
Preserving Biodiversity
1.
2.
3.
4.
5.
6.
Set aside large wilderness areas to
preserve ecosystems.
Restrict development
Prevent poaching
Seed banks / germ-plasm banks to maintain
crops and other plants
Captive breeding programs (zoos)
Genetic engineering - cloning of species
California Condor
Facts about the condor








Largest bird of prey in the US
Wing span up to 9 feet
Feed only on carrion
Nest in cliff caves in the mountains, large
trees and snags
Have only one chick at a time, only every
other year
Dependent on parents for over a year
Do not reach sexual maturity until 5-6 years
Were extinct in the wild until 2 populations
were found and bred in captivity
Causes of Decline




Natural Causes
Climate change
Restricted range due to shifting of
vegetative zones
Loss of ice age megafauna






Anthropogenic Causes
Habitat loss due to urbanization, limiting range
Converting grasslands into agriculture
Removing old growth forest leading to…
 Loss of food, loss of breeding/nesting habitat
 Reduction of food source (bison/deer and elk)
 Lead poisoning from shotgun pellets in carrion
Hunting for eggs, skin, trophies, sport, or
mistaken identity
At one time, there were only 22 birds in the wild!
Measures to protect the species
Legislative measures
Lacy Act- prohibits transport of live animal, dead animals or
parts across state lines without a federal permit
Endangered Species Act
CITIES
Creation of Wildlife refuges
Ban use of specific pesticides (DDT)
Artifical population measures
Captive breeding/incubation of eggs
Public Education
Tagging
Thanks to the conservation-breeding program, within 20 years
the population of California condors grew to almost 200 birds. It
took a variety of techniques developed by scientists and bird
keepers to do this. Eggs were removed from condor nests,
encouraging the females to lay replacement eggs. This is
called "double clutching.” The removed eggs were placed in
incubators for hatching. To make the hand-raised condors feel
like they were being raised by their parents, the newly hatched
chicks were fed and cared for using adult look-alike condor
puppets. Taped sounds of adult condors were played to the
chicks as well. In the wild, both parents incubate the egg and
care for the chick, and they may only raise one chick every
other year. As of July 31, 2011, there are 399 California
condors, including 198 birds currently living in the wild.
The Whooping Crane
Facts about the whooping crane





They primarily eat crustaceans, small fish,
insects, amphibians and reptiles. They’ll also
eat grains, marsh plants and acorns
Are about 6 feet tall
Breed in Canada and winter in Texas
Considered one of the most endangered birds in
NA
Lays only 2 eggs at a time
Causes of Decline

Habitat loss due to urbanization, wetland
destruction, agricultural modification of
flyway, natural disasters




Loss of food resources
Food web disruption
Loss of breeding/nesting/migration habitat
Anthropogenic Causes

Hunted for feathers, meat, eggs, skins, trophies,
sport or due to mistaken identity
Measures to protect the whooping
crane







Lacey Act (1900)
ESA
CITIES
Creation of wildlife refuges
Clean Water Act- protects wetlands
Migratory Bird Treaty
Wetland preservation measures
More protective measures…
Artificial Population Measures
 Captive breeding/incubation of eggs
 Teaching of alternative
flyways using ultralights
 Public education
 Population monitoring
such as tagging, GPS
and public reports of sightings

Songbirds- Where have they gone?






Approximately 70% of the nearly 10,000 bird
species are declining
12% are threatened with extinction
Main cause is habitat loss, degradation and
fragmentation
¾ of birds live in forests
Most dramatic declines are the migratory
songbirds (habitat loss and nonnative species
such as rats, snakes and mongooses) Collisions
with power lines, skyscrapers and
communication towers
121 million are hunted, 1 billion fly into glass
windows
Why care about the birds?




Birds are excellent indicators- they respond
quickly to changes in their habitats and are
easy to track and count
Control rodent/insect populations
Remove dead animal carcasses
Spread plants throughout their habitats by
pollination and excreting seeds
Robins, blackbirds and starlings prosper
around humans
Why protect the Condor or any species?

Ecologically



Economically



Maintain biodiversity – genetic diversity,
synergism with other species, keystone species
Niche value- matter cycling, trophic level
Ecotourism
reestablish population for commercial harvest
(fish)
Has an intrinsic value

Value based on its existence, regardless of its
usefulness
Why not protect the condor or any
other species?

Ecologically




background extinction
Focus is on the species and not habitat
Another species may occupy the same
fundamental niche
Economically



Expensive due to fund, developmental
restrictions, decrease value of land
Goods produced from have value (ivory, skin)
Dangerous or destructive to humans/property
The IUCN Red List
International Union for Conservation of Nature and
Natural Resources
 is an international organization dedicated to finding
“pragmatic solutions to our most pressing
environment and development challenges.” The
organization publishes the IUCN Red List, compiling
information from a network of conservation
organizations to rate which species are most
endangered. It is s widely recognized as the most
comprehensive, objective, global approach for
evaluating the conservation status of plant and
animal species.
The goals are to:
 Identify and document those species most
in need of conservation attention if global
extinction rates are to be reduced; and
 Provide a global index of the state of
change of biodiversity.

The percentage of species in several groups
which are listed as critically endangered,
endangered, or vulnerable on the 2007 IUCN
Red List

Critically endangered endangered vulnerable
ALWAYS AN ISSUE…


Developers vs environmentalists
Human needs vs biodiversity protection (jobs
and survival)
Threatened and Endangered species show us
that our world may not be as healthy as we
think.
Do You Think Humans Should Try to
Prevent The Extinction of Other Species?