Of the 19 pilot whales found beached on Cape Town's shores, at least seven have died despite the efforts of the local population.

Many of those remaining are still in poor health, according to the South African Press Association. 

Efforts to rescue the whales have largely been anchored in transporting them to the Simonstown naval base and releasing them back into sea. Meanwhile, police and other services attempt to keep the animals alive by wrapping them in sheets soaked with water.

However, of the five that have been successfully released, one of them has already re-beached, according National Sea Rescue Institute Spokesperson Craig Lambinon.

Those that are not successfully refloated back into the ocean will likely be euthanized.

This is not the first time pilot whales have beached in mass. In 2011, a pod of approximately 100 were found stranded on a remote beach in New Zealand where most of them died. A year later, 28 more were found in the same bay.

According to the Whale and Dolphin Conservation, most whales die within a few hours of beaching. Furthermore, beachings vary in trend depending on the region of the world. In Europe, for example, dolphins and whales commonly beach when they become old, sick or wounded. In areas like New Zealand, however, they often come ashore in mass and show no signs of illness.

One possibility for beaching among healthy groups is that the animals' use of echolocation in shallow water where the sand is soft and loose can cause disorientation. 

Another theory lies in the deep kinship often exemplified by many types of whales and dolphins, especially to those whom they are maternally related. A drive to protect or aid failing comrades drifting toward shore may cause all of those in the group to follow them even as far as beaching.

A recent study published in the Journal of Heredity disputes this theory on the grounds that in the cases in which DNA was collected from stranded animals, with few exceptions it did not show maternal familial connection.

In all, while pilot whale populations are unknown, they are estimated at approximately 200,000 and thus are not considered endangered. And because they easily adapt to captivity, they are commonly found at aquariums and zoos and have even been used by the U.S. Navy to locate and retrieve military equipment deep in the ocean.