Create turtles netlogo Patch#

Then flip the switch to on for about the same number of ticks. Run the simulation with the SHARING? switch set to off for awhile. For anyone wishing to demonstrate a reversal design, this model provides a 'hands-on' demonstration. What is the effect on age? Is it the same effect for energy? What about population?ДЄ nice feature of the model is that sharing can be turned on and off as the model runs, allowing for an easy comparison of the effects during the same run. Look closely at the effects of sharing across different initial conditions. The model is set up to allow the user to quickly see the effects of sharing and not-sharing on turtle population, age, and energy.

At the ar right, a histogram shows the distribution of the age of the turtles. * To the right of the sliders on the bottom of the screen, three figures plot the total number of turtles and the total number of patches with resources, the mean age and the mean energy of the turtles, and the median age and median energy of the turtles. * Monitors on the top of the screen that show the total number of turtles alive at a given moment, the total number of patches with available resources, the mean age of the turtles, the median age of the turtles, and highest age of the turtles at a given time, and the mean amount of energy, median amount of energy, and maximum amount of energy of the turtles at a given time. Watch the effects of your manipulations using one or more of the many monitors and graphs provided. * Change the **behavior of the turtles** by switching the SHARING? switch on or off. * Change the amount of energy required to **give birth** to a new turtle by using the BIRTH-ENERGY slider. * Change the **rate at which resources are replenished** by using the REPLENISH RATE slider.

Create turtles netlogo Patch#

* Change the **amount of energy each green patch provides** by using the ENERGY-FROM-RESOURCES slider. * Change the **number of turtles** using the NUMBER slider.

Users can examine the affects of changing the following variables: SETUP clears all settings, creates turtles, and resets the ticks to 0. Regardless of the SHARE? setting, turtles who occcupy a patch with other turtles are set to cyan. * To aid visual analysis, the colors of the turtles who do not occupy a patch with other turtles is set to orange when SHARE? is _off_ and yellow when SHARE? is _on_. * When SHARE? is set to _on_, turtles who occupy the same patch (green or black) share all of their energy equally between each other. * When SHARE? is set to _off_, turtles never share ENERGY and when more than one turtle occupies a green patch, one of the turtles consumes all of the available ENERGY from the patch. A turtle dies when its ENERGY reaches 0 or below, or when AGE is greater than OLDAGE, a number determined by the OLDAGE slider.ДЄ SHARE? switch determines the color of the turtles and how resources are consumed or shared _when turtles occupy the same patch_. Turtles and hatchlings start with AGE at 0. The turtle 'giving birth' loses an amount of ENERGY equal to the BIRTH-ENERGY, and the hatchling starts with the same amount of ENERGY. Turtles who reach a certain amount of ENERGY, set by the BIRTH-ENERGY slider, hatch a new turtle. Turles lose 1 unit of ENERGY each time they move. Each turtle starts with 10 ENERGY, and increases ENERGY by moving onto patches with energy (i.e., green patches). The rate that patches produce energy is determined by the REPLENISH-RATE slider.ДЄ number of turtles determined by the NUMBER slider are placed randomly on the starting screen and move in random directions, one patch at a time. The amount of ENERGY the patch produces is determined by the ENERGY-FROM-RESOURCES slider. When ENERGY is available, the patch turns green. This model is designed to evaluate the effects of 'selfishness' versus sharing on the population, age, and energy of turtles in a simple ecosystem.Д®ach patch randomly produces energy. In this extension, turtles can be instructed to share _all of their resources_ with turtles who occupy the same patch. In the tutorial, turtles never share resources and when more than one turtle occupies the same patch, the first turtle on the patch consumes all of the resources (if there are any). This extension adds an additional variable: sharing. Sustainable systems result in oscillating patterns of turtle populations and resources.

The tutorial provides a simple demonstration of a limited ecosystem in which turtles consume resources, reproduce, and die.

This is an extension from the model included in the tutorial in the **NetLogo User Manual** (as of November, 2018). Do you have questions or comments about this model?