Causes and ConsequencesCauses and ConsequencesProminent species & causes
◦Endangered Species◦Overexploitation by humans
Causes and ConsequencesCauses and ConsequencesObscure species & causes
◦Habitat destruction◦Plants & insects◦Loss of free services◦Loss of genetic diversity
Habitat DestructionHabitat Destruction
Thousands threatened vs. a few overexploited◦Plowing, logging, overgrazing, flooding,
draining….Dependence on habitats
◦Birds mature tropical forests◦Bats caves◦Trout Can’t breed in acidic or too
warm water
Human impactHuman impactNPP
◦3% of NPP – by one species◦Direct + indirect use (40%)
2/5ths of terrestrial food production Fires, conversion (forest pasture), non-used
NPP
Human population projectionSeas
◦Whales & fishes◦Extinction crisis not as bad◦Open seas safer
Ecosystem ServicesEcosystem ServicesGas cycle disruptionDeforestation
◦Freshwater supplies, increases danger of floods
Insects – pollination of cropsBiological pest controlSubterranean organisms – fertility
of soilAffected without being endangered
Number of PopulationsNumber of PopulationsEnsure persistence vs. short term
changes ◦Spread the risk
Genetic diversity◦Evolutionary potential in the long
term◦Lost even without extinction
ConsequencesConsequencesFood
◦Climate change, soil erosion, water supplies, decline of pollinators, pest problems
Benefits from genetic diversityDiseases
◦e.g. air pollution
SolutionsSolutionsHuman PerceptionNatural reserves not adequate
◦Scarcity, climate changeControl of human population
growthTechnologyAttitudes – public awareness
Planetary KillerPlanetary KillerGradual & subtle declineRed List by IUCN
◦Extinct◦Extinct in the wild◦Critically endangered
Sumatran rhino◦Endangered
Indian rhino◦Vulnerable◦Near threatened◦Least Concern
Some CausesSome CausesPoaching
◦Black RhinosOverharvesting
◦FishIntroduction problem
◦Rats, ants, mosquitoes, weedsConversion of natural
environmentsGlobal warming
Trees as critical casesTrees as critical cases976/100,000Living deadOne or few individual / species
◦Chinese hornbeam◦Hibiscus
Concentrated endangerment◦Juan Fernandez islands
20 species < 45 indivs
Historical Extinctions by Historical Extinctions by HumansHumansExtinction without discovery
◦Po’ouliIslands
From the top of the foodchain downBig birds, seals, penguins, songbirds, fish,
shellfish
Australia & New ZealandAustralia & New ZealandAustralia
◦16/263 mammals extinct by European settlers
◦34 in the Red List◦Aboriginals – 60,000 years ago◦Large Mammals first◦Ground birds/tortoises
New Zealand◦Polynesians◦No mammals
Rabbits, deer, rhinos◦Moas, New Zealand Eagle
MadagascarMadagascar88 millions years of isolationMega animals
◦Giant lemur◦Elephant birds
1100 AD, first human settlements
Mediterranean AreaMediterranean AreaAncestral humans
◦Tortoises + marine shellfishAgriculture effects in the Fertile
CrescentWoolly mammoth, woolly rhino,
Irish elk
Africa & Asia◦Cradle of human species◦Humans as native species
Filter principle of conservation biology
Extinction ratesExtinction rates1000 – 10000x1/million year
◦1/500,000 years for mammals◦1/6 million years for echinoderms
Current Extinction RatesCurrent Extinction RatesCount the number of extinctions
observed◦Birds/flowering plants
Assume the endangered species go extinct◦¼ mammals, 1/8 birds
Projections/models◦Habitat- species relationships◦Descent patterns through the red list◦Survival probabilities of species
PVA