Notoedric mange, a disease caused by mites, becomes epidemic in western gray squirrel populations and is a major source of mortality. Other species of eastern gray squirrels, fox squirrels, California ground squirrels and wild turkeys are expanding and compete with the western gray.
Principles of Design. Unity/Harmony. Definition of Unity: occurs when all of the elements of a piece combine to make a balanced, harmonious, complete whole. Unity is another of those hard-to-describe art terms but, when it's present, your eye and brain are pleased to see it. Definition of Harmony: brings together a composition with similar units.
Elements of Art. The elements of art are components or parts of a work of art that can be isolated and defined. They are the building blocks used to create a work of art. The list below describes each element of art. Learn about the principles of design here. Download a student handout containing a list of the elements of art and their definitions.