Abstract

Although thought to be fairly common off the western and southeastern coasts of South America, Burmeister’s porpoise (Phocoena spinipinnis) has seldom been seen alive by cetacean researchers. Published sightings are reviewed and new observations described. Animals seen in the wild appear light brown to brownish black; the most notable field characteristic is the low, backward-leaning dorsal fin with tubercles along its forward edge. Swimming is unobtrusive, with little of the body exposed and little water disturbance, making the animals almost impossible to see in rough weather. In calm weather the porpoises can be located by their short ‘puff-puff’ respirations. All sightings were in inshore waters, but incidental captures occur to at least 50km offshore. The porpoises enter bays, fjords and rivers and are sometimes found within the kelp line. Most sightings were of less than six individuals. Calves thought to be less than a month old were seen in Tierra del Fuego in January and April. Burmeister’s porpoises are often seen near but not directly associated with other species. At Golfo San Jose, Chubut, Argentina, porpoises were studied from 1974-76, 1981-1988 and again in 1990, in inshore waters in spring and summer. Sightings were much more numerous in 1990 and the animals occupied a wider area of the bay, possibly occupying niches left by bottlenose and dusky dolphins, which have been much less numerous in the area in recent years. As in Chile, animals may move offshore following prey in winter. Opportunistic sightings in Canal Beagle, Tierra del Fuego, indicate that there is a resident group(s) near Ushuaia/Lapataia, seen all months except August and September. These animals may be filling a niche left by Peale’s dolphins which were exploited by the centolla industry. Little is known about the biology and ecology of this species.