1. Endangered Species

2. What makes a species prone to extinction?
Narrow Geographical Range
If they only have one specific habitat, and it is destroyed they often become (geographically extinct)
Captive breeding of isolated populations in zoos often is the final state.
Small Population/Low genetic diversity
Small population = Lower genetic diversity = less resilient to change
Large predators and extreme specialists are often in this category
Low population density(Reproduction)
Large territories and low populations make it tough to find each other
Habitat Fragmentation contributes can make it worse
Few Populations
If only 2 populations (a group of the same species living in the same area capable of interbreeding) are left and one gets destroyed…

3. What makes a species prone to extinction?
A large body
Top predators = big animals = little energy = competition = rare
Also often hunted for sport
Low (r) Reproductive potential
Slow and infrequent reproduction makes recovery tough
Ex. Penguins produce one egg per pair per year
Seasonal Migrants
Hazardous journeys
Require 2 habitats to stay in tact/healthy
Habitat Fragmentation is also a problem
Poor Dispersers
Can’t easily move
Biome shift is a big deal for these organisms

4. What makes a species prone to extinction?
Specialist (Niche/feeding requirements)
Specialists rely on constant conditions and change happens often
Edible and tasty! Or valuable pelt/parts
Overhunting/overharvesting

5. Islands Dependent on size of island and distance from shore
Populations tend to be small
Islands have high degree of endemic species (Narrow range)
Low genetic diversity
Vulnerable to introduction of non native predators

6. Minimal Viable Population Size
The population that is needed for a species to survive in the wild
Depends on many factors
Genetic diversity, (r), mortality rate, growth rate, current threats
For large carnivores about 500 is often considered the absolute minimum.

7. IUCN Red List IUCN Red List Criteria Endangered Species Act
International Union for Conservation of Nature and Natural Resources
(World Conservation Union)
International Agency founded in 1948
Composed of 83 states, 110 GOs, and over 800 NGOs, scientists and experts from 181 countries
Red List Criteria
Monitor World Species through redlists
Endangered Species Act
1973 United States
Listing done by the Fish and Wildlife Service