Pygmy Right Whale

The pygmy right whale is rarely encountered and consequently little studied. However, it is known that it is by far the smallest of the baleen whales. Calves are estimated to be about 1.6 metres (5 ft 3 in) to 2.2 metres (7 ft 3 in) at birth (an approximately 2 metres (6 ft 7 in) fetus was reported from a 6 metres (20 ft) female that had stranded in Perkins Bay, Tasmania, in 1982). Calves may be weaned when they reach 5 months old. By the time they are weaned, they may be about 3 to 3.5 metres (9.8 to 11.5 ft) long. It is believed they become sexually mature at about 5 metres (16 ft) and physically mature at about 6 metres (20 ft). The longest male registered, was a 6.1 metres (20 ft) individual which had stranded in Cloudy Bay, Tasmania, while the longest female was a 6.45–6.5 metres (21.2–21.3 ft) individual which had stranded in Stanley, Tasmania in 1981. Pygmy right whales can weigh as much as 3,430 kilograms (7,560 lb). A 6.21 metres (20.4 ft) female weighed 3,200 kilograms (7,100 lb) and a 5.47 metres (17.9 ft) male weighed 2,850 kilograms (6,280 lb). Gestation and lactation periods and longevity are all unknown. Part of the reason for the scarcity of data may be the relative inactivity of the whale, making location for study difficult. …

The pygmy right whale is among the least-studied cetaceans; until 2008, fewer than 25 sightings of the species had been made at sea. The total global population is unknown. This small, elusive whale lives solely in the Southern Hemisphere, where it is believed to be circumpolar, living in a band from about 30°S to 55°S (in areas with surface water temperatures between 5 and 20 °C (41 and 68 °F). Individuals have been beached or washed-up on the coasts of Chile, Tierra del Fuego, Namibia, South Africa, Australia and New Zealand. At least one group may be year-round residents off Tasmania. In Namibia, several instances of pygmy right whales being found beached (possibly due to tidal fluctuations) and successfully helped back out to sea have occurred, including in 2010 in Walvis Bay and in 2014 near Lüderitz; in these instances, the whales were effectively cared for and analyzed before eventually being repositioned and guided by boat back to the open water. There is an extralimital stranding record in the Northern Hemisphere.

Analysis of the stomach contents of dead pygmy right whales indicates that it feeds on copepods and euphausiids (krill). The social and mating structures are unknown. The whale is typically seen alone or in pairs, sometimes associated with other cetaceans (including dolphins, pilot whales, minke whales, and once a sei whale cow and calf). Occasionally larger groups are seen — in 2001 a group of 14 were seen at 46°S in the South Pacific about 450 km southeast of New Zealand, while in 1992 a group of about 80 individuals were seen 320 nautical miles (590 km) southwest of Cape Leeuwin and another group of over 100 individuals were sighted in June 2007 about 40 kilometres (25 mi) southwest of Portland, Victoria. The maximum swimming speed of pygmy right whales has been estimated at 6–8 knots (11–15 km/h; 6.9–9.2 mph). The flukes, blubber, and baleen plates of a pygmy right whale calf were found in a 7.47 m (24.5 ft) killer whale caught by whalers off South Africa.