Figure 3.

This image shows a frame of the video collected by the camera positioned to record the top of table1B, with two birds present. Here many of the characteristics that increase the complexity for the feature detection algorithm can be seen. These include the small size of the birds in the frame, two of the many possible orientations of the birds, reflections on the food table, shadows cast by the birdseed containers, obstruction of the bird by the birdseed container, and the Mourning Dove blending into the background