Each tick is one day and each season is 91 days. This can be changed in the script so that e.g. months are monitored instead. The patches are colored according to favored areas each season. When run (Go) the butterflies leave the chrysalis in spring and summer. The butterflies turn into caterpillars at autumn, and pupate in a chrysalis in the winter. The model is an example of how turtles can change the behavior and appearance depending on the season.
This is a companion discussion topic for the original entry at