As the tiger population in Eastern India's Similipal Tiger Reserve bounces back, a rare genetic mutation is identified in the population known as pseudo-melanism. While the mutation is harmless, it causes the tigers to have distinctly dark coats, a trait now shared by roughly half the 30 or so tigers that roam the Similipal reserve. National Geographic Explorer and photographer Prasenjeet Yadav notes that scientists found these "black tigers" to be indicative of a limited gene pool in the region