Ecology Part 3Populations

Rabbits, Rabbits, Rabbits!

• How do populations grow?• Complete activity on p.118 in your book. Record all your answers on

a separate sheet of paper.

Characteristics of Populations

•Population Density•Number of Individuals per unit area (how crowded an area is)

Characteristics of Populations

•Geographic Distribution•The area inhabited by a population•Can vary in size between a few centimeters to a tree to the whole ocean

Characteristics of Populations

•Growth Rate•How fast the population reproduces

Population Growth

Births Deaths

Immigration/Emigration

Population Growth

•Generally populations grow if the number of births is greater than the number of deaths.• Immigration is the number of individuals entering a population (not by birth)•Emigration is the number of individuals leaving a population (not by death)•Can you think of reasons why individuals may immigrate or emigrate (not humans)?

Limits to Growth

•A LIMITING FACTOR is something that causes a population to decrease•Competition•Predation•Parasitism/disease•Drought/extreme climate•Human disturbances

INTERACTIVE

•Give me an argument about why limiting factors are good.•Give me an argument about why limiting factors are

bad.

INTERACTIVE

•Imagine 2 cups of soil. You plant 3 bean seeds in one cup and 15 bean seeds in another. Draw what the 2 cups of soil might look like in 3 weeks.

Human Population Growth

Watch and Reflect

Who Eats Whom, Part 1

• What factors play apart in the deer population of Arizona?

Predator and Prey Populations

• How does Predation affect a population?