Lecture 13 Biodiversity: Extinctions & ConservationToday’s focusPowerPoint PresentationPassenger pigeonCarolina ParakeetSlide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12What increases a species’ risk of extinction?Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Habitat fragmentation- localized clearing; reduction of large habitat into smaller, isolated patchesSlide 21Slide 22Slide 23Slide 24Slide 25How to classify risk of extinction? IUCN Red ListIUCN Red ListSlide 28Slide 29Slide 30ESA (enacted in 1973)What is the point of the ESA? Species protection or Habitat protection…How a darter made it to the Supreme Court…Tellico Dam, Little Tennessee RiverSlide 35Slide 36Slide 37Federally listed fishes in GeorgiaSlide 39Slide 40Slide 41Slide 42Slide 43Slide 44Lecture 13Biodiversity: Extinctions & ConservationECOL 1000: Ecological Basis of Environmental IssuesUniversity of GeorgiaSpring 2015Today’s focus•What are “extinction events”?•Should we be concerned about current extinctions?•Which animals are at highest risk for extinctions?•What mechanisms are in place to reduce extinctions?By most estimates, more than 99% of all species that have lived on Earth have gone extinct.Extinction is “normal”. But, are current extinctions “normal”?Passenger pigeon•Initially enormous flocks•1 mile x 300 mile flock, with billions of birds, perhaps the most common bird on the planet•Communal bird, with hundreds of nests together•Hunted by both native Americans and colonists•1850’s railroads gave easier access to hunting•“no ordinary destruction can lessen them”•The last one, “Martha” died in captivity in 1914Carolina Parakeet•A parrot endemic to the eastern US•Habitat destruction, hunting for feathers, collecting for pets, and being shot as “pests” greatly reduced numbers•Reason for extinction unclear, but perhaps contact with poultry disease•The last one, “Incas”, died in captivity in 1918Extinction event: a sharp decrease in the diversity and abundance of macroscopic life; occurs when the rate of extinction increases with respect to the rate of speciation. •In the past 540 million years there have been five major extinction events; these are events when over 50% of animal species died. •The most recent, the Cretaceous (K-T) extinction event, occurred approximately 65.5 million years ago.The K-T event was likely set off by an asteroid impacting in the Gulf of Mexico•Polar bears co2 global warmingEach previous extinction event has resulting in open ecological niches.This has lead to the emergence of new species, creating the diversity of life we see today (3-100 million species?).Remember from the previous talk, there have never been more species on Earth than now…Extinction event: a sharp decrease in the diversity and abundance of macroscopic life; occurs when the rate of extinction increases with respect to the rate of speciation.The background rate of extinction is the average rate of extinction that occurred before the appearance of humans•Based on the fossil record, the background rate of extinction on Earth is about 1 species out of every 10 million per year. •So, if there are ~10 million species on Earth, around 1 species would be expected to be lost per year, on average.Current estimates put us at somewhere around 1,000- 10,000 x’s the “background” extinction rate!Loss of Life Loss of Life  Within 10 years : 10 Within 10 years : 10 % lost% lost Within 25 years : 25 Within 25 years : 25 % lost% lost Within 50 years : 50 Within 50 years : 50 % lost% lost Within 10 years : 10 Within 10 years : 10 % lost% lost Within 25 years : 25 Within 25 years : 25 % lost% lost Within 50 years : 50 Within 50 years : 50 % lost% lost( E.O. Wilson et al., 1993 )( E.O. Wilson et al., 1993 )What increases a species’ risk of extinction?•Endemic populations or a few local populationsBlue poison frog, SurinameWhat increases a species’ risk of extinction?•Endemic populations or a few local populations•Species that migrate seasonally (if one habitat disappears, species will not persist)What increases a species’ risk of extinction?•Endemic populations or a few local populations•Species that migrate seasonally (if one habitat disappears, species will not persist)•Specialized habitat requirementsWhat increases a species’ risk of extinction?•Endemic populations or a few local populations•Species that migrate seasonally (if one habitat disappears, species will not persist)•Specialized habitat requirements•Large home ranges (fragmentation restricts the availability of habitat)Florida panther Large home ranges and isolation of individuals increasesrisk of extinction Natural habitat corridors needed (for mixing genetics, finding mates, catching food…)What increases a species’ risk of extinction?•Endemic populations or a few local populations•Species that migrate seasonally (if one habitat disappears, species will not persist)•Specialized habitat requirements•Large home ranges (fragmentation restricts the availability of habitat)•Conflicts with humans or used by humansWhat are the main threats to biodiversity?Habitat loss and alterationDecline of forests in eastern Madagascar (loss of >90% forest cover)Atlantic coast forests of Brazil Loss of many endemic species and others are threatened (golden lion tamarinHabitat fragmentation- localized clearing; reduction of large habitat into smaller, isolated patchesThreats to Biodiversity •Habitat Loss & AlterationHabitat Loss & Alteration•Invasive SpeciesInvasive SpeciesDozens of tree snails live in Hawaii are now endangered species, although were once abundant. Had not only ecological but cultural significance in Hawaiian folklore and songs; shells were used in lei and other ornaments.Predatory Rosy wolf snails &Giant African land snailsCNN African snails in Florida videoThreats to Biodiversity •Habitat Loss & AlterationHabitat Loss & Alteration•Invasive SpeciesInvasive Species•CoextinctionsCoextinctionsThe flightless bird Moa The flightless bird Moa was driven to was driven to extinction on New extinction on New Zealand by settlers, Zealand by settlers, followed by Haast’s followed by Haast’s Eagle which relied on Eagle which relied on the Moa for foodthe Moa for foodThreats to Biodiversity •Habitat Loss & AlterationHabitat Loss & Alteration•Invasive SpeciesInvasive