The moment was caught on the camera as the quake rocked Southern California, offering a rare glimpse at how elephants react to danger. In the footage, the large mammals run around initially, then older elephants Ndlula, Umngani and Khosi move to form a ring around calves Zuli and Mkhaya, in what experts call an “alert circle.”

When the ground started shaking, a herd of African elephants at the San Diego Zoo Safari Park formed a protective barrier, known as an "alert circle," around their youngest. Experts say it's a demonstration of their sharp instincts,