‘Pilot’ error responsible for disaster

HITLER mesmerised Germany and people followed him in their millions.

But, as subsequent events so tragically showed, blind devotion to leaders has its risk.

Pilot whales, it’s thought, also have a Führer but, in their matriarchal society, the boss is female. This ‘pilot’, from which the species gets its name, seems to call the shots, deciding where the pod goes and the routes to be taken. But her leadership, like Hitler’s, can end in tears. Was ‘pilot error’ responsible for the disaster at Rutland Island off Burtonport this month?

On November 8 last, 33 pilot whales became stranded on a beach there. All of them died. Nobody is sure just how such tragedies happen but unfamiliarity with shallow waters seems to be a crucial factor.

Pilot whales are a deep-water species; shallow bottoms are seldom encountered by them. Occasionally, however, they approach the coast in search of food. Here they stumble on reefs and shoals, unfamiliar terrain. If the leader gets confused and takes a wrong turning or two, the entire pod may end up stranded on the shore.

The long-finned pilot whale is actually a large dolphin. It is black all over except for a whitish stripe on the under-belly. As the name implies, the dorsal fin is quite prominent and curved backwards. Females, although physically the smaller sex, manage to rule the roost. Males, which can be up to six metres long, remain members of the pod but they don’t breed with their own group’s females. A sort of ‘incest taboo’ dictates that they visit other pods where they consort with females in ‘love them and leave them’ fashion.

Pilots are among the most sociable of whales. They move in tight formations and sleep so close to each other that their fins can touch. Unlike other dolphins, they don’t approach boats or ride bow-waves. Pilots don’t flee if approached. Pods usually have 15 to 200 members, although schools of up to 3,000 have been reported.

As with most highly socialised animals, pilot whales have a complex communication system. Their ‘songs’ squeaks and buzzing sounds are much studied but, so far, not understood. It’s clear, however, that vocal communication and navigation by echo location are important for pilot survival and this has made hearing impairment a prime suspect in strandings. Parasites or an ear infection, it’s thought, could render a pod leader incompetent and unable to detect what lies ahead.

Fingers have been pointed at naval exercises. Submarine detection systems emit extremely loud noises underwater – their echoes enable enemy vessels to be located. Detonations of mines, depth-charges and shells could produce sound waves so intense that they damage the sensitive ears of whales.

But pilot whale strandings were recorded long before the invention of submarine detection systems. A thousand whales became stranded together in Iceland in 1929. Indeed, the propensity to become trapped on shore has been used by whale-catching communities for centuries. Icelandic records show that 40 pilot whales were driven onto a beach there in 1704 and 150 were captured in 1815. Tomás O Criomhtháin, in An tOileánach, describes a stranding on the Blaskets. He refers to the victims as porpoises ‘with their great fins sticking up out of the water, all of them close together’, a perfect description of a pilot whale pod.

Such hunting, now much frowned upon, still continues on the Faroe Islands where whales are driven into small bays and slaughtered. The islanders justify this barbarity by appealing to ‘tradition’; their records show that whales were captured in this way from at least 1584 onwards.

From the point of view of strandings, however, some interesting facts have emerged from the annual hunts. Analyses of tissue samples show high levels of toxins. Indeed, the chief medical officer of the Faroes has declared whale meat no longer fit for human consumption; it’s little wonder that pilots get sick. The roundups also show how dependent pilot whales are on their leaders. Individuals managing to escape the ring of boats don’t swim out to sea and safety. Instead, they turn and head back to their distressed companions and die in the massacre.