NetLogo User Community Models

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## WHAT IS IT?

This model simulates how two types of swallows — short-winged and long-winged — navigate through traffic made up of moving cars. It demonstrates how physical traits (like wing length) can affect the swallows' ability to avoid danger and survive. The simulation can be used to explore the concept of natural selection, especially how maneuverability impacts survival rates in different environments.

## HOW IT WORKS

The model has 2 different types of swallows:

- Short-winged swallows are more agile and try to avoid cars using directional movement based on nearby obstacles.

- Long-winged swallows are less agile and use a simpler, more random strategy to avoid cars.

Swallows start at the bottom and move upward, trying to cross the screen.

Cars start from the top and move downward.

When a swallow collides with a car, it dies and a new one is spawned to keep population sizes constant.

The number of cars on screen is always adjusted to match the car-count sliderl.

## HOW TO USE IT

1.Sliders:

car-count: Adjusts the number of cars in the simulation. The model keeps the number of cars equal to the value adjusted on the slider throughout the simulation.

2.Buttons:

setup: Initializes the model, placing 25 short-winged, 25 long-winged swallos, and the number of cars set by the car-count slider.

go: Runs the simulation. Swallos and cars begin to move and interact.

3.Plots:

Swallow Deaths: Displays the cumulative number of deaths for both short-winged and long-winged swallows over time.

## THINGS TO NOTICE

- Which type of swallows survive more often?

- How does the number of cars affect the death rate of both short-winged and long-winged swallows?

- Do short-winged swallows successfully avoid more collisions compared to long-winged swallows?

- How does the difference in maneuvering behaviour impact the overall survival?

## THINGS TO TRY

- Increase or decrease the car-count slider and observe how each type of swallow is affected.

- Try running the simulation multiple times to see if one type consistently survives more.

- Observe the plot over time and compare the rate of deaths for both swallow types.