Ndlula, Umngani and Khosi — scramble to encircle and shield the two 7-year-old calves, Zuli and Mkhaya, from any possible threats.

The zoo reported the herd returned to normal behavior a few minutes after the earthquake, though they continued to remain close.

Witness the San Diego Zoo elephants' natural response to a 5.2 earthquake as they form an alert circle to safeguard their herd.