Marley, an African penguin, looks over a mirror at The Knoxville Zoo March 15, 2012. In an experiment to test the animal's responsiveness to its reflection, two mirrors with holes drilled in them were used in conjunction with small cameras to record the results. A GoPro Hero 2 and an iPhone 4 were used in the process to film the animals. (ADAM BRIMER/NEWS SENTINEL)
Knoxville Zoo animals react to seeing their reflection in mirrors. The mirrors had an iPhone 4 and a GoPro Hero 2 camera mounted to the back of them to capture the reactions. Photos in this gallery were made with the iPhone 4, iPhone 3Gs, GoPro Hero 2 and Nikon D3s.