In breeding programs aimed at conserving animals from small or isolated populations, scientists must balance the competing needs of adding genetic diversity and avoiding the introduction of harmful genes. 

How, in fact, do we count tigers?

Researchers from San Diego Zoo Global and Embryo Plus South Africa performed an ovum pick-up (OPU) procedure on Nikita, a 9-year-old female southern white rhinoceros at the San Diego Zoo Safari Park’s Nikita Kahn Rhino Rescue Center, on March 6.