instructor and web site 4 john marzluff 4 123 e anderson, 616-6883 4 [email protected] 4...
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Instructor and Web Site
John Marzluff 123 E Anderson, 616-6883 [email protected] Office Hours (by appointment) E-mail list [email protected]
Web Site http://courses.washington.edu/vseminar
Helpful Web Sites http://www.wa.gov/wdfw/ (Wa. Dept. of Fish and Wildlife home page) http://www.nceet.snre.umich.edu/EndSpp/factsheet.html (fact sheets on
endangered species) http://thomas.loc.gov/home/thomas2.html (links to all legislation) http://www.fws.gov/r9endspp/endspp.html (USFWS Endg. Spp. Home
page) http://web.lexis-nexis.com/congcomp (Access to federal register) http://www.fws.gov/laws/digest/digest.html (USFWS law descriptions) http://www.endangeredspecie.com/ (info source for species and pubs) http://www.umich.edu/~esupdate/index.html (Endangered Species
Update)
Introduction to the Class
Goals– Understand the processes of endangerment and
extinction
– Understand the methods used to recovery endangered species
– Understand the legislative environment surrounding endangered species management
– Contribute to the recovery of endangered species by working on projects defined by local, regional, and national organizations
Introduction to the Class
Assumptions– Basic working knowledge of principles of
conservation biology• Not going to address reserve design, gap analysis,
details of habitat plans, or island biogeography– May be interested in taking ESRM 450, Conservation
Biology or Landscape Ecology
– Willingness to work outside of class on projects– Willingness to work as a contributing member
of a team
Introduction to the Class
Expectations– Study the reading material
• it is EXTENSIVE, but Important
– Discuss ideas in class and with classmates outside of class
– Prepare a project• suitable for agency/publication
• oral and written presentation
• can continue on with project as independent study if interested
Procedures
Text Books– Stanford Environmental Law Society (required)– The Endangered Species Act at Thirty (recommended)
Primary literature on the web site Lecture slides on web Guest Lectures Project
– Teams,gather information, write report, update us in lab with oral presentations
– Interested students can stick with it next quarter for additional credit as needed
Rarity and Extinction
Why are some species rare? How do we classify rarity? Why are rare species prone to extinction? What is the historical pattern of extinction? Where is endangerment now occurring and
what are the causes?
Why are Some Species Rare? Body Size Trophic position Geographic distribution
– islands
– endemics
Degree of ecological specialization– niche width
Reproductive rate Recentcy of speciation
Classification of Rarity (Rabinowitz 1981)
Large Range Small RangeGeneralHabitatRequire-ments
SpecificHabitatRequire-ments
GeneralHabitatRequire-ments
SpecificHabitatRequire-ments
LocalPopulationsSomewhereLarge
BrownRat,Starling
RedMangrove
PygmyCypress
SilverSword
LocalPopulationseverywheresmall
PeregrineFalcon
Osprey Alala AlpineLilyGiantPanda
Why are Rare Species Prone to Extinction? Demographic Stochasticity
– By chance alone population fluctuates in growth rate and hence change in size from one year to the next
– When population is small, extinction can occur with relatively high probability even if chances of survival and successful reproduction are high
Demographic Stochasticity lx = 0.9 (probability of survival) mx = 0.95 (probability of successful
reproduction) If only 2 individuals are in area of interest, the
probability of extinction approaches 20%– both could die (.10 x .10) = .01 1%– 1 could die (.9 x .1) + (.9 x .1) = .18 18%
• thus population would be functionally extinct (no breeding pairs)
Why are Rare Species Prone to Extinction? Environmental Stochasticity
– random series of environmental changes that affect all members of a population similarly
– a couple of bad years in a row can be especially devastating to rare populations
• El Nino and Alala– Poor reproduction, even in captivity
– Compounding effect of predators (Io)
» specializing on crows more?
Why are Rare Species Prone to Extinction?
Catastrophes– Rare, but huge effects
Recent study by Spiller et al. (1998) quantified effects– Hurricane Lili hit Exuma Islands (Bahamas) in 1996 (first
since 1932)• high winds and 5m ocean surge
– Surveyed lizards and spiders on 19 islands before and after• 11 islands hit full on, 8 were protected by large island
Moderate Catastrophe Protected Islands
– lizards down 34%, spiders down 79% right after storm• Larger animals can weather moderate disturbances better
than small ones
– lizards did not increase appreciably during first year, but spiders did
• smaller organisms can rebound from catastrophe more quickly because of high reproductive rate
– Population size influenced likelihood of extinction in spiders
Major Catastrophe
Exposed Islands– All lizard and spider populations went extinct– Spiders rebounded within a year, lizards did not
recolonize in first year.• First colonist on Krakatoa was also a spider!
Why are Rare Species Prone to Extinction? Genetic Problems
– Difficulty Finding Mates– Genetic Drift
• Inbreeding Depression– Close relatives breed, heterozygosity goes down because they
share many alleles, semilethal recessives are expressed more frequently
– Aa x Aa gives 25% aa, if a is lethal when homozygous then these offspring will not survive
• Random Changes in Phenotype• Decreased Genetic Variance
More Genetic Problems Reduction in Effective Population Size
– EPS = size of “ideal” population that looses genetic variation at same rate as does real population
– Variation is lost at 1/2N% per generation, and replaced at mutation rate per generation--this loss and creation usually balance out
– Loss is at > 1/2N% when sex ratios are not balanced, mating is not random, age distribution is not stable, population size is stable, and reproduction is not equal among breeders
Effective Population Size
0
0.1
0.2
0.3
0.4
0.5
0.6
0 10 20
Generation (t)
Het
eroz
ygos
itiy
(al
l po
pula
tion
s) Census population was n
= 16 flies In theory, given ideal
conditions, we would expect decline in heterozygosity to follow solid lines.
Data fits line with ideal population of n = 9, thus the Ne = 9, not 16
Theory, N = 16
Theory,N = 9
Data
H=2pq(1-1/2N)t, under idealconditions (theory)
Extinction Vortices Summarize the Interaction of
Genetic and Demographic Problems (Gilpin & Soule
(1986)
Environmental changes typically set up positive feedback loops between a population and its environment than accentuate impacts and may lead to extinction– R vortex– D vortex– F vortex– A vortex
R Vortex Basically compounding demographic
stochasticity– Low N leads to increased variation in r which makes
population vulnerable to further disturbances lowering N even more
– Low N could lead to skewed sex ratio which makes it difficult to find mates, which lowers reproduction, which lowers N even more, which skews sex ratio further, increasing difficulty, lowering reproduction, lowering N……...
D Vortex
Lower N affects spatial arrangement of population by increasing fragmentation and isolation of demes
Fragments of population are of very small size, so they decline faster, which increases isolation more and speeds decline faster
F Vortex
Population decline reduces Ne, which increases inbreeding which reduces population growth, lowering N further and increasing inbreeding further
A Vortex
Population decline reduces Ne and genetic variation which reduces a population’s ability to respond to changes in the environment (loosing race to see Red Queen)– this increases the lack of fit between population
and environment, which increases decline further, reducing ability to adapt further…..
Combined Vortices
All types of vortices feed off one another, greatly increasing probability of extinction in small populations– Population becomes fragmented
• each deme is now smaller and susceptible to demographic stochasticity (R vortex) and inbreeding (F vortex)
• species cannot adjust to environmental changes (A vortex), so population declines further making it more susceptible to demographic stochasticity (R vortex), which accentuates fragmentation…..
What is the historical pattern of extinction?
Five major mass extinctions through geologic time– Late Permian--formation of Pangea, loss of shallows, many
marine organism extinctions (Schopf 1974)
Loss ofDinosMostly
Marine
Shallows
(Myers 1997)
Causes of Historic Extinctions are Varied
Meteors Continental Drift Humans
– Pattern of extinctions during last 30,000 years (late Pleistocene) closely matches pattern of human colonization
Human Occupation of Earth
(Diamond 1998--Guns, Germs, and Steel)
Recent Extinctions are Most Common in Areas Recently Occupied by Humans
Colors indicate when significant extinction events occurred. Numbers indicate % of fauna that has goneextinct in last 100,000 years (Burney 1993)
Few Recent Extinctions, LongOccupancy byHumans
Recent OccupancyMany RecentExtinctions
So, Extinction is Natural, but Current Episode is Unusual Estimated to be 10 - 50 million species on earth
– Using 10 million, there are 5 million in tropical forests
– 2% of tropical forests are disappearing annually
– Translates into 27,000 species / year or 75 per day going extinct in tropical forests alone (Wilson 1992)
– This present rate is 10,000x greater than background rate through geologic time (Nott et al. 1995).
Continental extinction rates have increased from 10-7 to 10-4 species/species/year
Nott, et al. 1995. Current Biology 5:14-17
Global Change and Biodiversity
Loss of Species Pales in Comparison to Projected Loss of Populations
(Hughes et al 1997) Estimate that there are 220 populations per
species (1.1-6.6 billion globally) If population extinction is a linear function
of habitat loss, then 1800 populations go extinct each hour in tropical forests alone– 16 million per year!!
Estimates Of Extinction Such as This are Based on the Species - Area Curve
Log Area
Log# ofSpecies
S = cAz
This loss of areameans this loss of species
A Global Perspective on Endangerment Baillie’s (1996) analysis of the IUCN Red Data
Book Birds appear to be least threatened (at best facing a
10% risk of extinction in the wild in next 100 years)– 11% of world’s avifauna is threatened
– 25% of world’s mammals are threatened
– 20% of world’s reptiles are threatened
– 25% of world’s amphibians are threatened
– 34% of world’s fishes are threatened
(Pimm et al. 1995; Chapin et al 2000)
Vulnerable Orders Loss of all representatives of an Order would be
extreme pruning of tree of life Mammal orders at risk
– elephant, manatees, marsupial moles,opossum-like Microbiotheria --all species threatened
– horses, tapirs, rhinos; elephant shrews; monotremes; hyraxes; flying lemurs
Bird orders at risk– cranes, galliformes, parrots, doves, kingfishers & bee-eaters,
procellariiformes, grebes, kiwis, cassowaries
More Vulnerable Orders
Reptiles– tuatara, crocs, turtles are only groups well
surveyed and all have high level of threat (~40%)
Fishes– sturgeon & paddle-fish, coelacanth, minnows,
perch
Inverts– poor info, but mollusks top the list
Severity of Extinction 10% of all birds are threatened with extinction
– Not Random among families• Parrots, rails, cranes, pigeons, albatrosses, megapodes
– Low reproductive rates (Bennett and Owens 1997 Proc. Royal Soc. Lond 264:401-408)
– Should prioritize conservation efforts for these species
» (Hughes 1999. Bird Conservation International 9:147-154)
– Concentrated among island species• First colonists to pacific islands exterminated 50% of the
native birds
• Even worse on Hawaii—90-110 of 125-145 are extinct(Pimm et al. 1994. Phil. Trans. R. Soc. Lond. 344:27-33)
Geography of Vulnerability Mammals
– Indonesia (128), China and India (75 each), Brazil (71),………USA (35)
– Madagascar (44%), Philippines (32%)
Birds– Indonesia (104), Brazil (103), China (90)– Philippines (15%), New Zealand (15%)
Reptiles, Amphibians, Fishes, Inverts– Poorly assessed, but USA and Australia top the lists
Biodiversity is not evenly distributed across Earth5% of Earth holds 95% of most vulnerable bird species(Bibby 1994, Proc. Royal Soc. Lond.344:35-40.
US Patterns of Rarity, Endemism, Extinction, and Listings Dobson et al. 1997 Nature Serve 2000, 2002
– http://www.natureserve.org/index.jsp
“AtRisk”
Species at Risk
Endemic Species
Plant diversity, endemism, and rarity
5-4a,b,cSource: Precious Heritage (2000) © TNC, NatureServe
Vertebrate diversity, endemism, and rarity
5-6a,b,cSource: Precious Heritage (2000) © TNC, NatureServe
Distribution of Federally Listed Species
6-1Source: Precious Heritage (2000) © TNC, NatureServe
County Distribution of Federally Listed Species
6-2Source: Precious Heritage (2000) © TNC, NatureServe
Distribution of Imperiled Species by Ecoregion
Number ofSpecies
Number ofEndemic Imperiled Species
1-20
21-50
51-150
> 150
1-10
11-50
51-150
> 100
6-5Source: Precious Heritage (2000) © TNC, NatureServe
What Reasons are Listed For
Endangerment in US? (Czech and Krausman 1997)
Cause # EndangeredInteractions with nonnatives 305Urbanization 275Agriculture 224Outdoor recreation, tourism 186Ranching 182Water diversions 161Modified fire regimes,silviculture
144
Pollution of water, air, soil 144Energy exploration 140Industry and military 131
What Reasons are Listed For
Endangerment in US? (Czech and Krausman 1997)
Cause # EndangeredHarvest, intentional andincidental
120
Logging 109Roading 94Genetic problems (inbreeding,etc)
92
Wetland destruction 77Plant succession 77Disease 19Vandalism (destroy, but noharvest)
12
How Many Extinctions Have Been Documented in last 400 years?
Total of 611 totally gone, 30 more extinct in the wild()– Mammals 86 (3); 1.8%, most in Australia & West Indies– Birds 104(4); 1.0%, most in Mauritius, US, N Zealand– Reptiles 20 (1)– Amphibians 5 (0)– Fishes 81 (11)– Molluscs 230 (9); mostly gastropods on islands– Crustaceans 9 (1)– Insects 72 (1)– Other inverts 4 (0)
Extinctions
Evil Quartet (Diamond 1989)
Overkill– whales
Habitat Destruction and Fragmentation Impact of Introduced Species Chains of Extinction
– plants in Hawaii after loss of pollinators
Revisiting Threats
Habitat degradation/loss Alien species Pollution Overexploitation Disease
(Wilcove et al. 1998 BioScience 48:607-615) Naiveity?? (Berger et al. 2001. Science 291:1036-1039) Climate Change
Has Extinction Slowed Diversification?
Overall increase of familial diversity despite extinctions
Loss ofDinosMostly
Marine
Shallows
(Myers 1997)
Modeling study suggests that tree of life can be vigorously pruned and still maintain diversity
Nee and May (1997)– What fraction of evolutionary history in a taxon
is left when some proportion of species are lost?
– Losing 80% of the species still preserved 50% of evolutionary history (measured as branches in phylogenetic tree)
– Doesn’t matter if we chose species at random or optimally based on genetic history
But, Importance of Species Loss To Rest of Ecosystem Depends on its Role Many species perform critical ecosystem services
(keystones in that regard)– soil generation, pest control, regulation of weather
and climate, nutrient cycling, seed dispersal, etc, etc (Daily et al. 1997).
So extinctions may have snowball effects Remember that the reason we can document
extinctions from the past is in large part because of the loss of dinosaurs in Late Cretaceous!
Does it Matter?
Hell Yes– Much is unknown, so save the parts
• (Aldo Leopold once said the first sign of an intelligent tinkerer is to save all the parts)
– Biodiversity is connected to ecosystem function• Loreau 2000. Oikos 91:3-17
– How many rivets can we pop?• Ehrlich and Ehrlich 1983. Extinction: the causes and
consequences of the disappearance of species. New York: Ballatine Books
So, What Do We Do?
Use Scientific Method to Identify Threat
Determine Spatial Extent of Protection--Gap Analysis
REMOVE THREAT
Release Probeto Test if Threat
is Removed
Captive Breeding
MonitorRecovery
Restock
Managein situ
Set up Reserves
?
Recommendations to Save Birds in the Americas
Secure sites 241 Locate new sites 214 Estimate population size in sites 197 Study ecology 164 Manage sites 91 Control taking 49 Educate people 23 Captive management 23 Taxonomic study 8 Other 14Bibby 1994 Proc Roy Soc Lond 344:35-40
Example--Lord Howe Island Woodhen Down to 20 individuals, confined to two mountain tops Did experiments to determine impacts of
– food availability– rat predation– pig predation
Remove Pigs Captive Breed, reintroduce, local stock Population up to 160 and stable Now should do reserve planning to manage entire island
References Rabinowitz, D. 1981. Seven forms of rarity. In The biological
aspects of rare plant conservation. H. Synge (Ed.), Wiley & Sons, Chichester. UK.
Gilpin, ME and ME Soule. 1986. Minimum viable populations: processes of species extinction. Pp 19-34. In. ME Soule (ed.) Conservation Biology. Sinauer, Sunderland, MA.
Pister, EP. 1993. Species in a bucket. Natural History January:14-19.
Diamond, J. M. 1989. The present, past and future of human-caused extinction. Philos. Trans. R. Soc. London B 325:469-478
References
Myers, N. 1997. Mass extinction and evolution. Science 278:597-598.
Schopf, TJM 1974. Permo-Triassic extinctions: relation to sea-floor spreading. J. Geology 82:129-143.
Daily, GC. Et al. 1997. Ecosystem services: benefits supplied to human societies by natural ecosystems. Issues in Ecology #2
Wilson, EO. 1992. The diversity of life. Belknap Press, Cambridge Ma.
Grant, PR. 1995. Commemorating extinctions. Am. Scientist 83:420-422.
References
Meffe, GK and CR Carroll. 1994. Principles of conservation biology. Sinauer, Sunderland, MA
Hughes, JB, GC Daily, and PR Ehrlich. 1997. Population diversity: its extent and extinction. Science 278:689-691.
Dobson, AP. Et al. 1997. Geographic distribution of endangered species in the United States. Science 275:550-553.
Czech, B. and Krausman, PR. 1997. Distribution and causation of species endangerment in the United States. Science 277:1116.
References
Baillie, J. and B. Groombridge. (eds). 1996 IUCN Red list of threatened animals. IUCN, Gland, Switzerland and Cambridge, UK. 448 p.
Spiller, D. A., J. B. Losos, and T. W. Schoener. 1998. Impact of a catastrophic hurricane on island populations. Science 281:695-697.
Nott, et al. 1995. Current Biology 5:14-17 Pimm, SL, Russell, GJ, Gittleman, JL and TM Brooks.
1995. The future of biodiversity. Science 269:347-350. Chapin, FS III, et al. 2000. Consequences of changing
biodiversity. Nature. 305:234-242.