Population Simulation
Jackrabbits & Coyotes
Bellwork
Use the macroinvertebrate data table to answer the following Qs:
1.
2.
3.
4.
What is the water quality SCORE and ASSESSMENT?
Would you swim in this water? Explain why or why not.
Would adding POUCH SNAILS to the water make the water LESS healthy
than it is now….explain why or why not?
If the population of dobsonflies suddenly decreased, but the mayflies &
stoneflies stayed the same, what could that mean?
3
3
12
9
24
Excellent
1
2
1
1
Aquatic Macroinvertebrates react
differently
• They still exist in healthy
streams! Healthy streams have
everything (high diversity)!
• But beware of LARGE
populations of these…
Midges
Tubifex Worms
Pouch Snails
1. What is the relationship between the
Roadrunner & Wile E. Coyote?
2. Describe another real life example of
this kind of relationship.
Predator-Prey Relationship
Jackrabbits & Coyotes
• How do you think the size of a predator population
and prey population affect one another?
• Write a hypothesis (if…then…as measured by…)
Procedures- in lab notebook
• Spread out 3 rabbits (white) evenly across habitat (green sheet)
• Hold 1 coyote (red) 1ft above lab table, & drop it once to eat. Must
land on/touch a rabbit to eat it.
– 0 rabbits eaten= coyote dies; 1 rabbit eaten= coyote survives;
3+ rabbits eaten=coyote reproduces (add one coyote for ea. 3 eaten)
– Surviving rabbits double (reproduce) every generation
• Record & calculate info @ end of each gen
• Count out start #s for next gen & repeat for 18+ gens
If all coyotes die: 1 new coyote immigrates in
If all rabbits die: 3 new rabbits immigrate in
Example
3
6
1
1
0
2
3
4
3
4
1
0
0
1
How many rabbits must a coyote eat in one drop to reproduce?
0
0
Jobs
• Jefe- Mathematician today (makes sure everything is
counted & added correctly)- see me if you get to 200+ rabbits
• Recorder- double checks jefe’s math before starting
each round, makes sure everyone records info
correctly
• Materials- makes sure materials respected, put away,
in charge of spreading out rabbits evenly as possible
• Presenter- Measures drop distances each round,
makes sure no one moves coyotes until all eaten
rabbits counted & removed
Run your experiment!
Half-way Closure
• What kinds of things are LIMITS to how
big your jackrabbit or coyote population
can grow?
Update your Ecology Divider
Ecology Unit
1. Notes
-What is Life Notetaker
-Energy Flow Notes
-Trophic Levels & Rule of 10 Notes
-Biome Research Notes
-Biome Poster Notes
-Aquatic Macroinvertebrates & Water Quality
-Population Notes
2. Labs
-Cricket Mark & Recapture Lab
-Aquatic Macroinvertebrates Lab
3. Assignments
4. Tests
-What Is Life Quiz
Population Notes (after break)
Limiting Factors
What kinds of factors LIMIT how big the
jackrabbit & coyote populations can grow?
Limiting Factors
Limiting Factors = factors that limit the growth
of a population: food, water, shelter, & space
Carrying Capacity Analogy
Bucket = habitat/resources
Water = new births
Overflow = deaths due to
exceeding the carrying
capacity
Carrying Capacity
Carrying capacity (K) = # of individuals that
the environment can support
Overshoot
Estimate the carrying capacity
of hares ~40-60
Estimate the carrying capacity
of lynx ~20-30
Graph & Conclusion
• Graph how the population of jackrabbits vs coyotes
change over time (think about what kind of graph this
is…)
• Conclusion paragraph- in lab notebook under
procedures (complete sentences, separate paper)
Closure
Predator-Prey Population Graph
Do on
blank BW
spot
1. Which line do you think represents the prey population?
Explain why you chose it.
2. Which line do you think represents the predator population?
Explain why you chose it.
3. Estimate the carrying capacity of the prey population.
4. In what year did the prey population overshoot the carrying
capacity the most?
5. What does this mean about the limiting factors that year?
Closure
Predator-Prey Population Graph
1. Which line do you think represents the prey population?
Explain why you chose it. Green line, b/c bigger population
2. Which line do you think represents the predator population?
Explain why you chose it. Red, b/c smaller population
3. Estimate the carrying capacity of the prey population. 40 to 60
4. In what year did the prey population overshoot the carrying
capacity the most? 1865
5. What does this mean about the limiting factors that year?
There must have been lots of grass (or whatever prey feeds on), water, space, etc.
Sponge: Think about it…
Hunting permits are frequently issued to help control certain
populations of animals.
1. When would a state want to issue a LOT of permits for deer
hunting?
2. How could this affect the wolf population in the area?
3. Are deers autotrophs or heterotrophs? What about wolves?
Explain your answers.