Conservation Biology Chapter 8

LC

least concern- widespread and abundant

NT

near threatened-likely to qualify for a threatened category in the future

VU

vulnerable- facing a high risk of extinction in wild

EN

Endangered- facing high risk of extinction

CR

critically endangered- extreme high risk of extinction

EW

extinct in the wild

EX

Extinct

DD

data deficient

NE

not evaluated

IUCN Red List Assessment Advantages

Uses clear taxonomy, Standardize assessment process, Formal Listing and review process, A place to keep all of the records

IUCN Assessment Process

Collectives of experts in government agencies, universities, wildlife preserves, zoos, botanical gardens, and museums assess the populations

IUCN Red List of Ecosystems

The goal is to place organisms into categories that describe risk of collapse → characteristic native biota will no longer be sustained.

Threatened Species

Of the 96,951 species assessed, 26,840 are listed as Threatened

Endangered Species Act

Made government HAVE to protect these species

Biodiversity Regulations

Regulated by a balance of speciation and extinction

Extinction rates

E/MSY=E/S10^6/t; Number of species expected to go extinct in 1 million years per the number of species that exist

Expected Extinction Rate

Should expect 0.1 to 1.0 species to go extinct out of a million per year

Current Extinction Rate

Currently 100-10,000 times faster

Drivers of Extinction

I = P ✕ A ✕ T; Impacts on biodiversity = human population size ✕ Affluence ✕ Technologies

HIPPO + C

Habitat loss, invasive species, population growth, pollution, overexploitation, and (new one) Climate Change

Habitat loss

Habitat loss, degradation, and fragmentation is the biggest cause of loss of biodiversity

Local Changes to Biodiversity

Balance between local extirpations and introduction of new species due to migration or reintroduction

Species-Area relationships

Species richness increases with area but will level off

Longterm Monitoring

Repeatedly testing and sampling biodiversity at the same location over a long period of time

Controls of Extinction Risk

Population size (rarity), Specialists, Trophic Level→ carnivores, Large body size, Limited range, Population density, Endemism, Isolation

Allee effects

Set of phenomena in biology where population density influences the fitness of individuals.

Endemism

A species found only in one geographical location.

Neoendemics

Species that occupy small areas because they have only recently evolved from closely related species

Paleoendemics

Ancient species whose close relatives have all gone extinct.