Legislative Response to Endangerment Lacey Act (1900; amended 1981)

– Game birds and other birds, possession of protected species

Endangered Species Preservation Act of 1966– Habitat acquisition

Endangered Species Conservation Act of 1969– Inverts, trade,

– Started process that led to CITES

Endangered Species Act of 1973– amended 1978, 1982, 1988

CITES

Convention on International Trade in Endangered Species of Wild Fauna and Flora– Signed 3 March 1973, Implemented 1975,

Amended 1979– Requires permit for import or export of species

listed • includes body parts like ivory, leather, shrunken

heads, etc

ESA of 1973

Basic Intent and Purpose– “to provide a means whereby the ecosystems upon which

endangered species and threatened species depend may be conserved, to provide a program for the conservation of such endangered species and threatened species, and to take such steps as may be appropriate to achieve the purposes of the treaties and conventions set forth in subsection (a) of this section”

– “a law that plays in when local planning and zoning, state fish and wildlife efforts, the Clean Water Act, and Clean Air Act haven’t worked. It is the emergency room of conservation policy” (M. Beattie 1995)

Classifying Endangerment

Listing species is first step toward conservation

During listing they are classified as “Endangered” or “Threatened”– endangered- “any species which is in danger of extinction

throughout all or a significant portion of its range”

– threatened- “any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range”

What are T&E Functionally? Wilcove et al. (1993) reviewed characteristics of

listed species– Endangered animals (median values)

• 515 individuals, 1-5 populations

– Endangered plants (medians)• 99 individuals, 3 populations

– Threatened animals• 4161 individuals, 1-5 populations

– Threatened plants• 2499 individuals, 9 populations

IUCN Categories Much more biologically based (Mace and Lande

1991 and updates)– Extinct

– Extinct in the wild

– Threatened• Critically Endangered

• Endangered

• Vulnerable

– Lower Risk• Near Threatened

• Least Concern

Flow Chart of Categories

(Gärdenfors 2001)

Threatened IUCN Categories

Critically Endangered “extreme risk of extinction in the wild in the immediate future”

Endangered “high risk of extinction in the wild in the near future”

Vulnerable “high risk of extinction in the wild in the medium-term future”

(Gärdenfors 2001)

Applying IUCN at the Regional Scale

(Gärdenfors 2001)

ESA vs IUCN categories

Wilcove et al.’s analysis suggests that listed species in US under ESA are in two most critical classes of IUCN categorization – low number of indivduals (<5000) and few (<9)

populations– emphasizes that the ESA is REACTIVE not

proactive and shows why many species do not recover after listing--they’re too far gone already

But, What Do We Mean by “Species”?

ESA and CITES define species as “any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature”– plant populations do not get special consideration– NMFS often lists fish stocks (local non-

interbreeding populations) • concept of Evolutionary Significant Unit (requires

reproductive isolation)

What is Actually Listed? Wilcove et al.’s Analysis suggested that most listed species

were full species– only 20% of listed species were subspecies or

populations, but this varied by taxonomic group• birds---80% of listed “species” were subspecies or populations

• mammals--70% of listed “species” were subspecies or populations

• Mollusks--5%of listed “species” were subspecies or populations

• Plants--14% of listed “species” were subspecies or populations

Proactive or Reactive?

Seems the ESA is proactive for birds and mammals, but reactive for plants and inverts based on the type of unit that is listed.

Biological vs. Evolutionary Species Concepts ESA uses a biological species concept because

it emphasizes that groups to be listed are reproductively isolated from other such groups

But, if the goal is to preserve biodiversity, then what we really want to preserve is unique genetic material, thus the evolutionary species concept may be more appropriate

Biological vs. Evolutionary Species Concepts Evolutionary species are those lineages that maintain

their “own evolutionary tendencies and historical fates” (Wiley 1981)

The National Research Council (NRC) review of the ESA discusses the EU and suggests it may be an especially valuable way to view species for listing– Evolutionary Unit-- “group of organisms that

represents a segment of biological diversity that shares evolutionary lineage and contains the potential for a unique evolutionary future”

Defining EUs

The NRC suggests that EUs are “segments of biodiversity that contain a potential for a unique evolutionary future”– Define by distinctiveness from other units

• morphology, genetics, reproductive isolation, ecological distinctiveness, behavior, and physiology

– Hybrids can be included as EUs if they are not genetically dependent on parental species

Evolutionary Significant Units

•Others have defines EUs, or more generally, ESUs•Reviewed in Crandall et al. 2000

•Ryder 1986: populations that actually represent significant adaptive variation based on concordance between sets of data derived by different techniques

•Waples 1991: populations that are reproductively separate from other populations and have unique or different adaptations

•Moritz 1994: populations that are reciprocally monophyletic for mtDNA alleles and show significant divergence of allele frequences at nuclear loci

Ecological and Genetic Exchangeability

•Ecological exchangeability: the factors that define the fundamental niche and the limits of spread of new genetic variants through genetic drift and natural selection

•rejected with evidence for population differentiation owing to genetic drift or natural selection

•Differences in life histories, morphology, habitat, allozymes under selection (preferably heritable ones)

•Genetic exchangeability: the factors that define the limits and spread of new genetic variants through gene flow

•Rejected when there is evidence of restricted gene flow between populations

•Differences in microsatellites, nucleotide sequences, (mtDNA, cpDNA, nDNA) and allozymes

(Crandall et al. 2000)

Assessing Ecological and Genetic Exchangeability

(Crandall et al. 2000)

References Crandall, KA, Bininda-Emonds, ORP, Mace, GM, and RK Wayne. 2000. Considering

evolutionary processes in conservation biology. Trends in Ecology and Evolution. 15:290-295. Gardenfors, U. 2001. Classifying threatened species at national versus global levels. Trends in

Ecology and Evolution. 16:511-516. National Research Council. 1995. Science and the endangered species act. National Academy

Press. Washington, DC. Moritz, C. 1994. Defining “evolutionary significant units” for conservation. Trends in Ecology

and Evolution. 9:373-375. Ryder, OA. 1986. Species conservation and systmatics: the dilemma of subspecies. Trends in

Ecology and Evolution. 1:9-10. Waples, RA. 1991. Pacific salmon, Oncorhynchus spp., and the definition of “species” under

the endangered species act. Marine Fisheries Review. 53:11-22. Wiley, E. 1981. Phylogenetics: the theory and practice of phylogenetic systematics. New

York. John Wiley & Sons Wilcove, D.S, M. McMillan, and K. C. Winston. 1993. What exactly is an endangered species?

An analysis of the U.S. Endangered Species List: 1985-1991. Conservation Biology 7:87-93.