Transcript Powerpoint on Lynx & Hare lynx_hare_powerpoint

Lynx & Hare
Learning Objectives
1.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 Relationship
What 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 oneinch 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
Growth
J-shaped growth
Draw graph into your notes!
• In ideal conditions,
a population will
start growing
slowly, then
exponentially
• Example: in the
right conditions,
bacteria double
their population
each generation.
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
Draw graph into your notes!
• As a result of
limiting factors,
population
growth slows, or
stops
• The result is a Sshaped curve
• The top of the
curve is K
(carrying
capacity)
Example of S-shaped curve
Question: what do you think
might happen if a population
exceeds the carrying capacity?