Figure 4. Examples of shapes for constructed waterbird nesting islands: A. Sinuous and skinny would provide increased edge effect needed for visibility of predators by the birds. B. Doughnut-shaped would provide more edge than a solid circular shape while maintaining a low-disturbance area in the center. A canal would allow water to inner area to prevent problems associated with stagnant water (e.g. mosquito breeding). C. Ear-shaped with vegetated center area would increase the edge-to-area ratio but would allow increased accessibility to maintain vegetation. D. Coil-shaped, which is extremely sinuous and has many loops, would also result in increased edge effect. This shape could easily be created with a dragline or conveyor belt.