Sustaining Biodiversity: The Species Approach

Chapter 8

What role do humans play in the extinction of species?

Section 8-1

Case Study: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”)

• Hunted for food, feathers, fertilizer

Passenger pigeon

Great auk Dodo Dusky seaside sparrow

Aepyornis(Madagascar)

Some Prematurely Extinct Species

• No one knows how many have gone extinct due to human activities.• 99% of all species that ever lived have gone extinct—5 major mass extinctions in geological time. But is this the 6th and the first not caused by abiotic factors?

Extinction Rates• Current annual rate of species extinction is over 1,000

times the background extinction rate according to conservative estimates of 0.1% to 1% per year. (There are around 8.7 million species + bacteria. “Normal” extinction rate is 1 species per million per year = 0.0001%).

• The annual extinction rate is projected to rise to about 1% per year due to HIPPCO. At a 1% extinction rate, 25% - 50% of the world’s current species could vanish by the end of this century.

• Human activities might help to increase the speciation rates for other rapidly reproducing opportunist species such as weeds, rodents, insects, which could further accelerate the extinction of other species.

• What if we are wrong and it isn’t a “big deal”? Precautionary principle “look before you leap”/ “better safe than sorry”

Endangered and Threatened Species

• Endangered species could soon become extinct over some or all of its range

• (1228* in US16,000 globally)

• Threatened species still abundant, but likely to become endangered (about 376* listed in US30,000 globally)

http://ecos.fws.gov/ecp0/reports/box-score-report (2016)

Fig. 8-3, p. 154

Characteristic Examples

Low reproductive rate

Blue whale, giant panda, rhinoceros

Specialized niche

Blue whale, giant panda, Everglades kite

Narrow distribution

Elephant seal, desert pupfish

Feeds at high trophic level

Bengal tiger, bald eagle, grizzly bear

Fixed migratory patterns

Blue whale, whooping crane, sea turtle

Rare African violet, some orchids

Commercially valuable

Snow leopard, tiger, elephant, rhinoceros, rare plants and birds

Large territoriesCalifornia condor, grizzly bear, Florida panther

Characteristics of extinction-Prone species

“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

Percentages of various species threatened with extinction due to human activities

Why should we care about the rising rate of species extinction?

Section 8-2

Importance of Wild Species

• Natural services- air & water purification, nutrient cycling, pollination

• Economic Services (Resources) - food, fuel, lumber, paper, medicine

• Genetic information- better ability to adapt to changing enviro. conditions

• Recreational pleasure and ecotourism- generates > $1million/min. Lion generates $ 515k over 7 years elephant worth about $1 million over 60 yrs

• May take nature 5 -10 million years to replace the species that may be lost in your lifetime

• Do species have an intrinsic right to exist? Even small organisms can be important

EVERYTHING IS INTERCONNECTED

Nature’s Pharmacy

Bioprospectors – search for medicines from wild plants and animals62% or all cancer drugs originated from wild species9 of 10 leading Rx drugs originated from wild species

< 0.5% of flowering plants in tropical forests studied for medicinal properties

How do humans accelerate species extinction?

Section 8-3

How do humans accelerate extinction?

• Habitat destruction and fragmentation - GREATEST THREAT!

• Invasive (alien) species

• Population growth (humans)

• Pollution

• Climate Change

• Overharvesting/overexploitation

“HIPPCO”

Reductions in the ranges of four species

Extinction Threats from Habitat Loss and Degradation

• Importance of habitats--on average, a 90% habitat loss causes the extinction of 50% of the species living in that habitat. GREATEST THREAT! (Especially considering climate change will lead to more habitat loss)

• Deforestation- particularly tropical forests = greatest eliminator of species

• Destruction of wetlands and coral reefs

• Endemic species- found nowhere else on earth

• “Habitat islands”- surrounded by different habitat (national parks, lakes, mt. tops)

• Habitat fragmentation - continuous area divided into small, scattered patches

• “Message” from the birds - 70% are declining, 12% threatened with extinction Birds are indicator species

• EXAMPLE: US prairie dog--keystone species has lost habitat to agriculture and urbanization (plus often seen as a pest and exterminated)

H+

Introduced Species

• Some introduced species beneficial: corn, wheat, rice, cattle, poultry are critical to U.S. food supply

• Many introduced species lack natural predators, competitors, parasites, or pathogens that help control numbers in original habitats

• Invasive species: Outcompete native species, trigger ecological problems, human health problems, economic loss

• Threaten 1/2 critical species in US (95% in Hawaii)

I

See posters!

Harmful invasive speciesI

Kudzu “the vine that ate the South”

“The vine that ate the south” - grows up to a foot a day- engulfs everything in path, contributes to smog (emits NO): But, controls erosion edible, fiber for paper, medicinal (reduces desire for alcohol)

I

Zebra mussels attached to a water current meter in Lake Michigan

Zebra mussel •displaces species•depletes food supply•clogs pipes• jams ship rudders •grows in huge masses on boat hulls, piers and other solid surfaces.

I

Fire Ant Invasion

• Can wipe out 90% native ant population

• 2009 parasitic fly discovered as control: lay eggs in ant, maggots eat away ant brain causing their heads to fall off

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Reducing Threats from Nonnative Species

• $$$ Cost U.S. Taxpayers billions of dollars yearly

•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

I

Human Population GrowthImpacts other Species

I = P A T

P1

Review Ch 6

DDT in fish-eatingbirds (ospreys)

25 ppm

DDT in largefish (needle fish)2 ppm

DDT in smallfish (minnows)0.5 ppm

DDT in water0.000003 ppm,or 3 ppt

DDT inzooplankton0.04 ppm

Bioaccumulation of DDT

“Bioaccumulation” of toxins results in

increased concentrations of fat

soluble chemicals (called

“Biomagnification”) at higher levels of

food web.

Problem pollutants include:

DDT (pesticide), mercury & lead

(byproducts of coal and dirty fuel burning)…

P2

Where Have All the Honeybees Gone?

• Almost 1/3 of U.S. food supply comes from insect pollinated plants- honeybees responsible for 80% of food pollination

• Honeybee populations are in serious decline: In 2010 34% of all commercial bees in U.S. were lost

•Possible Culprits:pesticide exposure, virus, mites, fungal infection, poor nutrition (due to loss of forage plants), microwave radiation from cell phones & cell towers, invasion by killer bees,

•Pear orchards in China are now largely pollinated by hand $$$$

P2+

Great Pacific Garbage Patchplastic threatens millions of marine species

““Pacific Garbage Dump“Pacific Garbage Dump”“Pacific Garbage Dump” - Nightline Video - click here

Pacific Gryre Video - Pacific Gryre Video - “Pacific Gryre Video - “Great Pacific Garbage PatchPacific Gryre Video - “Great Pacific Garbage Patch”Pacific Gryre Video - “Great Pacific Garbage Patch”- click here

Great Pacific Garbage Patch- click

P2

Range change due to climate changesC

Specialized organisms with small ranges may be unable to adapt to shifts in climate.

Review Ch 15B!

Extinction Threats from Poaching

• Profits of poachingMt. gorilla = $150K; panda pelt = $100K;; rhino horn = $25k /Kg(most live animals die in transit)

• Causes of poaching: food, fur, pets, traditional medicines, trophies, eliminating pests, etc.

• Bushmeat -- warning: next slide gross

• Illegal pets and decorative plantsorchids can fetch up to $5K; saguaro cactus $15K> 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

O+

Illegal Selling, Poaching of Wild Species

Live mountain gorilla is worth$150,000

Rhino horn (for medicine) worth $25,000+ /pound

White rhino Bushmeat: factor in reducing some populations of orangutans, chimpanzees, elephants, and hippopotamuses.

O+

Marine Species: Sea Turtles

6 of World’s 7 sea turtle species are endangered or threatened.

Poaching, degradation of beaches, litter, and threats from fishing nets

HIPPCO Case study

Marine Species: Whales• 1.5 million whales killed from 1925 to 1975• 8 of the 11 major species driven to commercial extinction• blue whale driven to the brink of biological extinction

• Despite the ban on whaling, > 28,000 whales were killed between 1986 and 2010, mostly by the nations of Japan, Norway, and Iceland, which have openly defied the ban.

HIPPCO Case study

How can we protect wild species from extinction?

Section 8-4

Protecting Wild Species International Treaties

Convention on International Trade in Endangered Species (CITES), 1975• signed by 175 countries that bans the hunting, capturing, and selling of threatened or endangered species. • annual international meeting• limited impact due to spotty enforcement, ability for countries to except themselves BUT recent success with reduction in sale of ivory in China

Convention on Biological Diversity (CBD), 1993• legally binds governments to reverse decline of biodiversity• ratified by 191 countries (not USA) - No severe penalties

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.

AND…

*Endangered Species Act (ESA- 1973)- one of world’s toughest & most controversial environmental 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 2011 there were 1,371 protected species (many critical species not yet listed)

• requires shipment of wildlife only through designated ports

Endangered Species ActImperfect enforcement

Establishing critical habitats: ESA requires protection of critical habitat for recovery of listed species...• BUT only 33% of listed species have critical habitat established AND between 2001-07, gov’t under GW Bush stopped listing new species & designating critical habitats unless mandated by court order. 1% of listed species have been “delisted” (56 delisted total as of 2013, including bald eagle 2007)

Habitat conservation plans • BUT 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, SO criticized as loophole - many plans approved without scientific evaluation

ESA and commercial shipping: all commercial wildlife shipments must leave or enter US via designated ports• BUT 60 USFWS inspectors examine only 25% of 90,000 yearly shipments AND violators often not prosecuted and pay only small fine

Confiscated Products From Endangered Species

Due to sparse $$ and inspectors, < 10% of illegal wildlife trade in US is discovered

How Can We Protect Wild Species?

• The National Wildlife Refuge System: 553 refuges

• Gene / seed banks: >100 seed banks globally

• Botanical Gardens & Arboreta

• Farms for commercial sale: alligators, butterflies

• Zoos & Aquariums: captive breeding, egg pulling (incubate wild-laid eggs then return to wild)

Three big ideas• We are greatly increasing the extinction of wild species

via HIPPCO.• We should avoid causing the extinction of wild species

because of the economic and ecological services they provide, and because their existence should not depend primarily on their usefulness to us.

• We can work to prevent the extinction of species and to protect overall biodiversity by using laws and treaties, protecting wildlife sanctuaries, and making greater use of the precautionary principle.

Ch 8 focus: “species approach” to conservation. Next (Ch. 9), we’ll consider the “ecosystem approach”.