DISTRIBUTION

The long-finned pilot whale, also known as the pothead, is a common species in Newfoundland and Labrador waters and is abundant worldwide. It is widely distributed in all cold and temperate waters, with the exception of the North Pacific. Pilot whales can be found following squid inshore during the summer and autumn months. During the winter, they migrate out to the continental shelf of the Grand Banks and into the southern United States.

Pilot whales are generally an offshore species, but herds of the animals can be seen in the deeper bays of Newfoundland. Aerial survey work in the 1980s suggests about 14,000 pilot whales reside in Newfoundland and Labrador waters, but little is known of stock structure, migration and wintering habits off eastern Canada. It is generally assumed that they winter east of the Grand Banks, although historically large herds of eighty or more have been hunted and seen inshore during the months of January and February.

IDENTIFICATION

Pilot whales are a medium-sized toothed whale, and frequently found in inshore areas when squid are present. They are rarely seen alone, but travel in large groups of tens to hundreds of animals. They are relatively easy to identify at sea, due to the prominence of their wide, curved dorsal fin, which is set on a broad base, forward on the back. Females have a less prominent, but more pointed dorsal fin than males.

They are known as “potheads” because the head bears some resemblance to a cooking pot. In older males the forehead is so large that it often overhangs the beak. Potheads have long, narrow pectoral fins that are so curved they have the appearance of an elbow. The fins are one-fifth the total length of the whale. The torso is torpedo-shaped and narrows at the tailstock. The tail flukes are small, pointed tips and a slight middle notch.

Pilot whales are completely black, except for a white anchor patch under the chin and a narrow grey band running down the belly. Some whales also have a faint grey triangular saddle patch behind the dorsal fin.

The animals are often observed lying motionless at the surface, presumably resting. Individual pilot whales will often raise their heads above the water, a behaviour known as “spyhopping.” When they do this, their white “anchor” patch can be observed.

BIOLOGY

The pilot whale is the largest member of the dolphin family after the killer whale and false killer whale. They are highly vocal and emit a wide range of whistles and clicks.

The diet and distribution of pilot whales is closely tied to squid abundance and migration. However, they also take other fish species as cod and Greenland halibut (turbot). They coordinate their hunting activities by encircling schools of fish.

Pilot whales usually live to be around forty-five years of age, though animals as old as sixty have been reported. Females attain sexual maturity at age six and males at twelve years. They weigh around 1.5 to three tonnes. The average length for males is five meters, with females being shorter. Pilot whales have a calf about every three years, following a gestation period of twelve months. Calves are born between June and November and nurse for almost two years.

Pilot whales are highly social, and entire herds are known to follow a leader ashore and beach themselves. Mass strandings of this species occur with some regularity in various parts of the world. Strandings of up to 200 animals have been recorded in Newfoundland, one of which occurred in 1979 at Point au Gaul on the tip of the Burin Peninsula when 139 beached themselves and died. Point au Gaul, with its gently sloping headland that juts into the sea, is typical of the topography for mass strandings of pilot whales.

HUMAN INTERACTION

Scientists have derived much of their knowledge about the species from the Newfoundland pilot whale drive fisheries, where herds of animals were driven ashore and slaughtered. Between 1948 and 1971, approximately 54,000 pilot whales were taken during Newfoundland drive fisheries, mainly at Dildo and Chapel Arm. Drive fisheries for pilot whales are still conducted on the Faroe Islands.

In Newfoundland, pilot whales were mainly hunted to supply meat to the fox farming and pet food industries. Oil and fertilizers were also manufactured from pilot whales.

Currently, the main risk for long-finned pilot whales comes from incidental entanglement in fishing gear, causing animals to drown. Nonetheless, the species is not generally considered to be in immediate danger globally.