Residents of Tiruchendur in Tamil Nadu came across an odd sight on Monday. Short-finned pilot whales, part of the oceanic dolphin family, had washed up on a 16-kilometre stretch of beach from Alanthalai to Kallamozhi, remaining marooned there. The number kept increasing, rising to more than a 100, with around 45 feared dead.

The Times of India reported local fishermen spending all night trying to save the whales by pulling them back to the sea. Officials in the area said the whales continued to seem disoriented, attempting to return back to the beaches even after they were pulled back out into the water. The Tuticorin district collector as well as a team from the Gulf of Mannar Marine National Park have made their way to the area to inspect the beaches.

Although whale beachings are not new – Aristotle is recorded having described some – the phenomenon is still somewhat mysterious. Whales are known to be social animals, moving around in groups and scientists believe that they decide to move in new directions en masse if they have somehow been disturbed in their own territory.

This disturbance can be due to any number of reasons: changes in water temperature, sonar, nutrient deficiencies and water pollution have all been suggested as possible causes. In Chile, last year, observers found more than 330 whales washed up on the shore, with scientists speculating that red tide might have been the cause.

In India, among the causes being considered are the two earthquakes on Monday in Philippines and Indonesia measuring 6.5 and 6.9, respectively, which could also have caused the disorientation in the whales.

NDTV quoting officials said the whales may have come from the Pacific Ocean and may be injured from the coral reefs and rocky shores of the Tamil Nadu coast. The post mortem reports may bring some clarity to this bizarre occurrence.