Lynx & HareLearning Objectives1.Students will be able to calculate population density.

2.Students will be able to graph the size of a population over time.

3.Students will analyze the factors (biotic and abiotic) influencing population size and/or limiting population growth.

4.Students will analyze a population graph to identify areas of exponential growth and/or carrying capacity.

Lynx

Arctic Hare

Predator & Prey

Predator/Prey RelationshipWhat happens to a predator

population when the prey population increases or decreases?

What happens to a prey population when the predator population increases or decreases?

Your Task

1. Your goal is to model changes in Lynx & Hare populations

2. Mark off your square with tape (2’ x 2’). This is your habitat

3. Use the Lynx and Hare cards to model how the numbers of individuals change over time

Important Reminders

Take care of the materials in this lab as several class periods will be using them.

Do not misplace, throw-away, crumple or otherwise destroy the one-inch snowshoe hares. Thanks for your help!

Analysis: Population Growth

Population Growth is affected by:

1. Births

2. Deaths

3. Number who leave or enter the population

Real Lynx & Hare Data

Question:

What was affecting the population of the lynx and hare in the activity?

Exponential GrowthJ-shaped growth

• In ideal conditions, a population will start growing slowly, then exponentially

• Example: in the right conditions, bacteria double their population each generation.Draw graph into your notes!

Limiting Factors• Of course, organisms cannot grow

exponentially for long• Factors that limit the growth of a

population are known as limiting factors

• Example: predation of hares by lynx limits the hare population

In the absence of lynx, what other factors might influence the size of

the hare population? hare population?

Brainstorm in your groups

Factors can either be:- biotic (living factor)or

- abiotic (physical, non-living)e population?Classify each of the factors you

brainstormed as biotic or abiotic.

Carrying Capacity The maximum

population that can be supported by an environment

The number is set by the availability of space, food, and other resources necessary for survival.

Carrying Capacity

S-shaped growth

• As a result of limiting factors, population growth slows, or stops

• The result is a S-shaped curve

• The top of the curve is K (carrying capacity)Draw graph into your notes!

Example of S-shaped curve

Question: what do you think might happen if a population exceeds the carrying capacity?