Biodiversity and the conservation of biodiversity have received increased attention during the last few decades and these topics have been implemented into many G7-12 science curricula. This work presents an exercise that may be used in middle and high school classrooms to help students better understand spatial aspects of biodiversity. The following activity was successfully implemented into 8th grade science classes to strengthen student understanding of biodiversity. In the activity, students are provided a sample dataset created using point-count surveys of avian species along a transect extending from forest interior to open field locations. Students are asked to calculate and analyze total bird density (n), species composition, species richness (S), and species diversity (H[prime]). By analyzing the data, students observe how these measures change along the vegetation gradient. The activity can easily be adjusted to accommodate a variety of skill levels and class times. (Contains 3 figures and 1 table.)