SAN DIEGO — As the ground shook from a 5.2-magnitude earthquake, a herd of elephants at the San Diego Zoo Safari Park sprung into action to protect their young.

A video shot of their enclosure at the park Monday morning shows the five African elephants standing around in the morning sun before the camera shakes and they run in different directions. Then the older elephants — Ndlula, Umngani, Khosi — scramble to encircle and shield the two 7-year-old calves Zuli and Mkhaya from any…