Populations

Specialist vs. Generalist Species

100

Smaller range of tolerance, or narrower ecological niche makes them more prone to extinction

What is a Specialist species?

200

• Broad food req.

• High adaptability

What are Generalist Species characteristics?

300

Larger range of tolerance, broader niche makes them less prone to extinction & more likely to be invasive

What is a Generalist Species?

400

• Specific food requirements (bamboo)

• Less ability to adapt to new conditions

What is an Specialist species characteristics?

500

Pandas, Quetzales and Koalas.

What are specialist species?

K-selected and r-selected species

100

• Few offspring, heavy parental care to protect them    

• Usually reproduce many times

what is K-selected species?

200

• Many offspring, little to no care 

• May reproduce only once

what are R-selected species?

300

• Long lifespan, long time to sexual maturity = low biotic potential = slow pop. growth rate

what are K-selected species?

400

• Shorter lifespan, quick to sexual maturity = high biotic potential = high pop. growth rate

What are R-selected species?

500

examples of:

• More likely to be invasive

• Better suited for rapidly changing env. conditions 

what are insects, fish and plants?

Survivorship Curves

100

• High survivorship early in life due to high parental care

what is Type I survivorship curve species

200

High mortality (low survivorship) early in life due to little to no parental care

what is Type III survivorship curve species?

300

• High survivorship in mid life due to large size & defensive behavior

• Rapid decrease in survivorship in late life as old age sets in

what is Type I survivorship curve species?

400

• Steadily decreasing survivorship throughout life 

what is Type II survivorship curve species?

500

• Few make it to midlife; slow, steady decline in survivorship in mid life

• Even fewer make it to adulthood; slow decline in survivorship in old age

what is Type III survivorship curve species?

Carrying Capacity

100

• when a population briefly exceeds carrying capacity

what is Overshoot?

200

• sharp decrease in pop. size when resource depletion (overshoot) leads to many individuals dying

  • Ex: many deer starve with too many new fawns feeding in spring

what is Die-off?

300

the max. Number of individuals in a pop. that an ecosystem can support (based on limiting resources)

what is Carrying Capacity (k)?

400

• resource depletion ex: overgrazing in deer

what is the consequence of overshoot?

500

1. Hare pop. increase due to low predator pop. (lynx)

2. Lynx pop. increase due to increase in food (hare)

3. Increasing lynx pop. limits hare pop; leads to die-off

4. Hare die-off decreases lynx food source, leading to die-off

5. Hare pop. increase due to low predator pop. (lynx)

what are examples of a relationship between Predator-Prey?

Pop. Growth & Resource Availability

100

Size, Density and Distribution.

what are population characteristics?

200

• total # of individuals  in a given area at a given time

  • Larger = safer from pop. decline

What is Size in populations?

300

• # of individuals/area

  • Ex: (12 panthers/km2)

  • High density = higher competition, possibility for disease outbreak, possibility of depleting food source

what is Density in populations?

400

• how individuals in pop. are spaced out compared to each other

  • Random (trees)

  • Uniform (territorial animals)

  • Clumped (herd/group animals)

What is Distribution in populations?

500

Population Size = 

(Immigrations + births) - (emigrations + deaths)

what is Calculating Population Change formula?