Stranded pilot whale found dead on Silhouette Island

A female pilot whale found on the beach (Island Conservation Society)

(Seychelles News Agency) - A female pilot whale has been found dead by a conservation team on a Silhouette Island beach in the Seychelles archipelago recently. Staff from the Island Conservation Society (ICS) and the Islands Development Company (IDC) found the marine mammal during routine monitoring activities undertaken on the scarcely-populated island’s beaches.

According to a press statement from ICS, the carcass, which was discovered on Baie Cipailles beach, was inspected by staff members, who recorded its body measurements and collected tissue samples in order to correctly confirm its species.

ICS confirmed the mammal, which was over four feet long, was a short-finned pilot whale, also known as tropical pilot whale, (Globicephala macrorynchus).

“There were numerous scrapes and lacerations on its body, probably caused by hitting the rocks in the reef,” said the statement. “It had been spotted swimming inside the reef on the previous day, but the reason for the stranding is unknown.”

“The carcass has been interred with the aim of preserving and collecting the skeleton once decomposition of the organism has concluded.”

The ICS, which also conducts monitoring operations to prevent poaching throughout the surrounding Silhouette Marine National Park, says that although the mammals are called pilot whales, they are actually a species of dolphin – the second-largest variety behind the killer whale, which is also from the dolphin family. Highly social animals, pilot whales live in pods comprised of between 15-50 members, although hundreds of the mammals have been spotted converging on one spot, possibly for mating purposes.

“Pilot whales are known as the ‘cheetahs of the deep’ for their high speed pursuits of squid (their favourite food) at depths of hundreds of metres. They also happen to be the cetacean most commonly found stranded on beaches – usually in groups – possibly as a result of geomagnetic anomalies, or sonar or seismic noise disrupting their navigation. However, when a single pilot whale is found stranded on its own, the cause is usually illness or injury,” added the conservation experts.

In a similar stranding incident in 2009, an extremely rare species of deep-diving whale called Deraniyagala’s Beaked Whale (mesoplodon hotaula) beached itself on Desroches Island. The toothed whales, which are distantly related to sperm whales, are thought to be found in deep ocean waters beyond the edge of the continental shelf throughout the Pacific and Indian oceans, but thus far only seven of the animals have ever been seen by scientists.