# Rabbit Population by Season Gizmo Answers

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A thing known as a population refers to a group of individuals of the same species. All of them live in the same area. There are a number of different factors that determine the size of a population. Everyone is able to see how different factors influence the way the rabbit population grows and changes in the Rabbit Population by Season Gizmo.

Talking about the Rabbit Population by Season Gizmo, there are some questions related to it. Some of them should be done before using Gizmo and some other should be done after using it. After doing all of them, you can check out the answers below:

Prior Knowledge Questions

1. Suppose you had a pet rabbit. What would the rabbit need to stay alive and healthy?

Food, water, and shelter

1. A female rabbit can give birth to over 40 baby rabbits a year. Suppose all of her offspring survived and reproduced, all of their offspring survived and reproduced, and so on. If that happened, in only eight years the mass of rabbits would exceed the mass of Earth!

So, why aren’t we overrun with rabbits? What keeps the rabbit population in check?

We aren’t overrun because rabbits are at the bottom of the food chain, therefore they are preyfor larger predators like eagles, hawks, and owls.

Gizmo Warm-up

1. Select the BAR CHART tab. What is the size of the initial rabbitpopulation?

40

1. Select the TABLE tab. Click Play ( ), and allow the simulation to run forone year.

A. In which season did the rabbit population increase the most?

Spring

B. In which season did the rabbit population increase the least?

Winter

Activity A: Carrying capacity

Question: What determines how large a population can grow?

1. Think about it: A limiting factor is any factor that controls the growth of a population. What do you think are some of the limiting factors for the rabbit population?

The amount of food available and their predators.

1. Run Gizmo: Select the DESCRIPTION tab. Set the Simulation speed to Fast. Select the GRAPH tab. Click Play, and allow the simulation to run for at least 10 years. (Note: You can use the zoom controls on the right to see the whole graph.)

A. Describe how the rabbit population changed over the course of 10 years

The increase in population grew steadily for more than half of the 10 years, but eventually started to decrease at a constant rate.

B. What pattern did you see repeated every year?

The Rabbit population in the Spring grew exponentially but then you would get to the Winter and see a loss.

C. How could you explain this pattern?

During the Winter food is scarce for rabbits.

1. Analyze: The carrying capacity is the maximum number of individuals of a particular species that an environment can support. All environments have carrying capacities.

A. What is this environment’s approximate carrying capacity for rabbits? (Note: Average the summer and winter carrying capacities.)

The total average is 384 with 426 during the summer and 342 during the winter.

B. When did the rabbit population reach carrying capacity? Explain how you know

The rabbit population hit carrying capacity during the summer and spring months. Weknow this because the population stopped rising and stayed constant.

Activity B: Density-dependent limiting factors

Question: How does a density-dependent limiting factor affect carrying capacity?

1. Think about it: What do you think some density-dependent limiting factors might be?

Predators, food, and shelter

1. Predict: Suppose a shopping mall is built near a rabbit warren, leaving less land available for rabbits. How will this affect the environment’s carrying capacity?

Rabbits will have less food which will ultimately lead to a decline in rabbit population.

1. Experiment: Use the Gizmo to find the carrying capacity with Ample,Moderate, and Little land. List the carrying capacities below.

Ample: 402          Moderate: 300                  Little: 109

1. Analyze: How did the amount of space available to the rabbits affect how many individuals the environment could support?

The larger the space available the larger the rabbit population was.

1. Infer: Why do you think limiting a population’s space decreases the carrying capacity?

This was because of the amount of food available.

1. Challenge yourself: Other than space, what might be another density-dependent limiting factor? Explain.

Predators could also be another density-dependent limiting factor because they aren’t only fighting for food, but also fighting to stay alive and to not become food for larger animals.

Activity C: Density-independent limiting factors

Question: How do density-independent limiting factors affect how a population grows?

1. Think about it: What do you think some density-independent limiting factors might be?

The weather type or the conditions of the environment they are living in, like is it clean or polluted.

1. Gather data: Click Play. Allow the population to reach carrying capacity. Click Pause ( ). Select the GRAPH tab and click the camera (��) to take a snapshot (or screenshot) of the graph. Right click the image and paste the snapshot into the box below. Label the graph “Normal Weather.

1. Predict: How do you think a period of harsh winters will affect the rabbit population?

It will cause the rabbit population to decrease.

1. Investigate: Click Reset. Select Harsh winter from the CONDITIONS listed on the SIMULATION pane. Click Play, and observe how the population changes over five years. �� Paste a snapshot (or screenshot)  of the graph in the box below. Label the graph “Harsh Winter.

A. How does the Harsh Winter graph differ from the Normal Weather graph?

The normal weather graph stays within a range while the harsh winter is slowly increasing over time but decreases drastically during the winter season.

B. What do you think most likely caused the differences seen in the two graphs?

During the winter season food is scarce, therefore the rabbit population decreases.

1. Predict: Rabbits reproduce in the spring. How do you think a period of cold springs will affect the rabbit population?

It will cause it to decrease drastically.

1. Investigate: Deselect Harsh winter. Select Cold spring. Click Play, and observe how the population changes over a period of five years. �� Paste a snapshot (or screenshot) of the graph in the box below and label the graph “Cold Spring.”

A. How does the Cold Spring graph differ from the Normal Weather graph?

The cold spring graph increases over time and has a very short decrease unlike the normal graph because it stays consistent within a high and low.

B. What do you think the most likely caused the differences seen in the two graphs?

The weather and how available the food was for them.

1. Predict: How do you think a period of hot summers will affect the rabbit population?

A steady increase with a small decrease during the winter months.

1. Investigate: Deselect Cold spring. Select Hot summer. Click Play, and observe how the population changes over a period of five years. �� Paste a snapshot (or screenshot)of the graph in the box below.  Label the graph “Hot Summer.

A. How does the Hot Summer graph differ from the Normal Weather graph?

The hot summer graph increases greatly compared to the normal graph.

B. What do you think most likely caused the differences seen in the two graphs?

The hot summer months produce more food compared to the winter months.

1. Think and discuss: Other than unusual weather, what might be another density-independent limiting factor that could affect the rabbit population? If possible, discuss your answer with your classmates and teacher.

Diseases and competition might also be another density-independent limiting factors that could affect the rabbit population.