ABSTRACT

RESUMEN

INTRODUCTION
Between the latitude of the southernmost point of New Zealand (47°S) and the main body of the Antarctic continent (70°S), the only land is the southern tip of South America, the Antarctic Peninsula and a few isolated islands. Throughout this immense area of water there is very little traffic. F The only ships passing are research vessels going to and from the Antarctic and a few fishing or whaling ships. The only planes are those flying to Antarctic bases. There are few beaches where dead or dying cetaceans can wash up, and the beaches that do exist, facing the west-east currents, are either so rocky that the animals are immediately broken up or so isolated that no one visits them. Thus, the smaller cetaceans of the South- ern Ocean are very incompletely known. Tierra del Fuego, the mass of islands off the southern tip of South America, extends down into the Southern Ocean and breaks the movement of its waters, which must pass between Cape Horn and the Antarctic Peninsula. There is a long history of large whale strandings in Tierra del Fuego (Bridges 1897, Castello and Piñero 1974, local residents pers. comm.) but until very recently practically no one noticed the smaller animals that washed up on the beaches, even though cool climatic conditions prolong the decomposition process. During expeditions along the beaches looking for botanical specimens, I began picking up a few skulls.   On learning of their rarity, expeditions were made especially for stranded cetacean material. It has become apparent that a great many animals strand on the coasts of Tierra del Fuego and that the majority of these have been lost to science. Specimens have been so numerous that most trips have had to be cut short for lack of space in transporting the bones. In one day, on the southwestern beach at Bahía San Sebastián, 88 specimens were col¬ lected.
AREA CHARACTERISTICS
The Archipelago of Tierra del Fuego is a maze of intricate channels and islands. The western and southern islands are steep and rocky and any cetaceans stranded there would probably soon be lost. It is impossible to get to that area without using boats. The northern and northeastern parts of the Isla Grande de Tierra del Fuego, however, are flatter and a series of roads allow access to stretches of sandy Sci. Rep. Whales Res. Inst., No. 30, 1978. or stony beaches. It is on these beaches that bones are left by the highest tides. I have had access only to the Atlantic coast and the eastern Beagle Channel in Argentine Fuegia and eastern Bahía Inútil in the Chilean part.  Place names of the areas collected are given in Fig. 1. There is a large tidal variance on the eastern coast of Tierra del Fuego, from 2.7 m in the Beagle Channel to 9.7 m at Rio Grande and a record 15.8 m at Rio Gallegos in the Province of Santa Cruz.  This tidal range coupled with a fairly flat continental shelf exposes great areas, especially in large, shallow bays such as Bahía San Sebastián. The western and southwestern shores of this bay have produced the greatest amount of stranded material to date.  In fact, this area is known to the men of the nearby Argentine border police station as the " cemetery of the whales." Bahla San Sebastidn. This large bay (53°10'S, 68°30'W) opens to the east ; the distance across the mouth is 18 km.  To the northeast, the bay is partially enclosed by the Península Páramo, a long narrow strip of land composed entirely of sand and Patagonian shingle (smooth round stones). The deepest part of the bay is near the tip of this peninsula, the Punta de Arenas, where the depth varies between 18.3 and 49.4 m (Derrotero Argentino, 1962). To the southeast of the bay are cliffs 60 ft (18 m) high. 1 Near the mouth of the bay in this section ships load oil from a moored pipeline.  Off-shore drilling within the bay is planned for the future. The whole western coast is an extensive flat beach of sand, clay and mud which, in places, is up to nine km wide. The large tides (the average height is about 10.5 m) and the very gradual slope of the beach combine to make the landing of even small boats almost impossible. This tidal beach area is muddy and slippery most of the year, but during the summer it dries out enough (except during the highest tides) to drive a vehicle from the mouth of the Rio San Martin (Fig. 2) north to the northwest corner of the bay, a distance of nearly 40 km. When standing on the beach at low tide, one cannot see the water of the bay. The winds are predominantly from the southwest and blow strongly through¬ out the year, although somewhat less in winter.  One would think that animals dying within the bay would be blown out to sea, but the greatest amount of stranded material is found in the windward part of the bay. ) The fishermen claim there is often an E-NE wind on a rising tide, which then changes to SW.  No official studies have been made of the currents within the bay, but Capt. H. F. Correa Luna (personal communication 1978), who has for many years captained the boat which connects the loading pipe line to the tankers, says that on the rising tide the currents are generally to the west in the center of the bay, SW in the southern part and NW in the northern. On a falling tide all the currents are to the E, gradually swinging to SE outside the mouth of the bay (Fig. 2). The tide rises and falls rapidly, but without much force, over this wide, gradual slope of mud flats. On the outer coasts where the water is deeper, the force of the falling tide is much greater. I feel that, apart from the dolphins caught in fishing nets, strandings in this Sci. Rep. Whales Res. Inst., No. 30, 1978. bay may be accidental, a result of the imperceptibly sloping beach, the rapidity of tidal rise and fall, winds, currents and the slippery, sticky nature of the mud of the tidal zone. The hypothesis of Dudok van Heel (1966) that an animal entering a large shallow area may have difficulty obtaining a good long-range echo  and an exit to deep water can only be found by trial and error, seems a definite factor at Bahía San Sebastián.  Although no studies have been made of the prey available in the bay, there must be a reason why so many species have been found there. Dudok van Heel's theory that animals concentrating on feeding may miss long distance sonar information and make mistakes in navigation seems an additional possibility.
EXPLOITATION
Although a whaling company operated out of Punta Arenas, Chile, from 1906 to 1916 (Goodall 1975) and whalers from many countries have operated in off-shore Sci. Rep. Whales Res. Inst., No. 30, 1978. waters, there has been no deliberate exploitation of the smaller cetaceans in Fuegian waters until recently when they have been taken for crab bait. Nevertheless, animals have been taken accidentally in fishing nets for many years. Centolla Net Fishing.   There is a large scale fishery for centolla or southern king crab ( Lithodes antarctica ) in Punta Arenas, Porvenir and Ushuaia.  Tangle nets, 1.30 m high and up to 1000 m in length, have been used for at least 15 years in the Beagle Channel and much longer in the mid-western Strait of Magellan. The nets are taken out in deep bays or channels, set, and left until the following day.   Cephalorhynchus commersonii, Lagenorhynchus australis and Phocoena spinipinnis are occasionally taken in these nets. Centolla Trap Fishing. The prohibition of tangle nets in Argentine Tierra del Fuego since 1976 has forced fishermen to change to crab traps, which require bait. In Argentine Fuegia, the only commercial crab fishing is in the eastern Beagle Channel, where there are few dolphins. The season is from 1 June to 15 December. When nets were used, the season was from October until December. The bait used is normally fish, caught by the crab boats or at San Sebastian by shore fisher- men. A few cases of taking sea lions ( Otaria flavescens ) and dolphins have been re¬ ported. In Chilcan Fuegia, the season is from 1 July until 31 January and both traps and nets are still used. Fishermen prefer to use dolphin meat as bait in the crab traps.  Sielfeld et al. (1977a, 1977b) estimated that in order to provide dolphin meat for all the traps during the 1976-77 season, 2,350 dolphins would have had to be killed. The actual number killed is unknown, as the fishermen do not prac¬ tice it openly. The capture or killing of smaller cetaceans has been prohibited by law in Argentina since 1976 and in Chile since 1977, but no control is yet enforced in either country. Robalo Net Fishing.   Fishing for robalo (Eleginops maclovinus), merluza (Merluccius australis) and pejerrey (Austroantherina sp.) occurs on the Atlantic coast of Tierra del Fuego. This fishing is sometimes done by nets carried along the beach between a boat and men on shore, but the more common method is to attach the net, at low tide, to a row of stakes perpendicular to the shore line, allowing the net to lay on the sand. On the rising tide, floats raise the net and fish feeding in the zone are entangled, along with occasional dolphins. For many years robalo fishing has been done in a small way by local fishermen who camped at places such as the Río Ewan mouth, Cabo San Pablo, Cabo Peñas, Cabo Domingo and Bahía San Scbastián. With the formation of a company during the 1976-77 season, fishing was intensified in Bahía San Sebastián.  Three camps were set up, with two long nets at the SW end of the bay and four on the W side of the Peninsula Paramo (see Fig. 2). Robalo is most abundant from October through March and it is only in this period that the operation is commercial. The species accounts which follow show a total of 28 Cephalorhynchus com¬ mersonii, one Lagenorhynchus australis and one Phocoena dioptrica caught in robalo nets in Argentine Fuegia during the last three years.  These represent only animals for which there are specimens. I have data on 15 other captures, but the actual number killed is probably very much higher. According to the fishermen, some animals return to the sea. Those caught on a rising tide drown, but Commerson's dolphins caught on a falling tide remain alive on the beach and swim off with the next high tide.   During low tide, several kilometers of sticky mud separate them from the water's edge.  I have no data on robalo fishing in Chile.
METHODS
The specimens reported in this paper were obtained by checking the beaches on foot, walking parallel to the coast, paying special attention to the zone above the highest tide line.    Along the Beagle Channel where there are few roads, beaches were checked on horseback or, occasionally, by boat.  Along the Atlantic coast, it is easier to get near the beach and at times, such as at San Sebastian in summer, to drive directly on the beach. But usually specimens have to be carried out in a backpack. Periodic visits were made to beaches that produced the most speci¬ mens. When the animals were sufficiently fresh, external measurements were taken, along with tracings of appendages, organ weights, samples and stomach contents. The processed specimens are in my collection in Ushuaia or at Estancia Harberton. The collection up to number RNP 90 was determined by Robert L. Brownell, Jr. and Edward Mitchell in October, 1975, while specimens up to RNP 332 were identified by James G. Mead in February, 1976.  Ricardo Praderi studied the collection in November, 1977.
THE SPECIMENS
Since most of these beaches had never been checked for cetacean material, a great quantity of very beach worn bones was found. Few of the early collections were in good condition and many of the skulls were broken or partial. At times, com¬ plete sets of vertebrae were found with the skulls, but usually the parts of a single animal were scattered. In one instance, two uniquely deformed Phocoena dioptrica vertebrae, which were found 18 months and 20 km apart, united perfectly. When the crania were found separately from the post-cranial skeletons, there is obvious overlapping in the collection, which probably contains more specimens than there were animals originally.  Care was taken that each cranial collection, at least, represent a distinct animal. The cool climate of Tierra del Fuego preserves dead animals for a considerable time. Fresh dolphins are often flensed by birds, mainly gulls ( Larus dominicanus ). Fishermen claim that a fresh Commerson's dolphin can be eaten in four or five hours, leaving the head and flukes intact, but with the major part of the vertebral column clean.   After this stage, the birds no longer touch the animal, which may then remain on the beach or be taken by the tide. The collection dates given Sci. Rep. Whales Res. Inst., No. 30, 1978. here do not necessarily indicate the stranding date ; most animals had been there a long time. This paper deals only with general information on the collection.  Detailed data on the individual species will be presented later. Explanation of Tables. Localities (in kilometers) are abbreviated to north and south of a known point. On the west side of Bahia San Sebastian, where most of the specimens were collected, distances are taken north and south of the border between estancias San Martin and Cullen, which is near the middle of the west side of the bay and is marked with a fence. On the basis of the fusion of the vertebral epiphysis, an indication of age is given. Total fusion, adult; fusion to thoracics, subadult; only caudals fused, immature. This classification does not indicate sexual maturity. A specimen denoted as ''nearly complete'' usually lacks only a flipper, scapula, a few caudals or pelvic bones. Other abbreviations: R, right; L, left; Ea., estancia or ranch; v, vertebrae; r, ribs; imm, immature; v. imm., very immature; subad., subadult; *=caught in robolo nets; #=caught in centolla nets. The initials RNP are used for the cetacean collection to differentiate from RNPG, used for my botanical collection.  C & G specimens were those collected by H. P. Castello and R.N.P. Goodall in 1974.
FAMILY  DELPHINIDAE
Lagenorhynchus australis (Peale 1848) Peale's dolphin, Blackchin dolphin, Delfin Austral This is a coastal species known from northern Chile around Cape Horn to the Patagonian coast in Argentina (Brownell 1974, Aguayo 1975). Brownell (1974), summarizing the known records of this dolphin, shows a number of sight records but no specimens from the Tierra del Fuego area.  Aguayo (1975) states that the Norris expedition on the R.V. Hero in 1968 collected nine specimens be¬ tween the Golfo de Arauco and Cape Horn.   Praderi (1977) gives information on seven museum specimens. Although I have not had much opportunity to see dolphins in their natural habitat, my experience is that Peale's dolphin is very common throughout the channels and bays of Tierra del Fuego, but more numerous in the southern part, such as the Beagle Channel, while Cephalorhynchus commersonii is more numerous in the Strait of Magellan.  Local residents confirm this impression.  Peale's dol¬ phin is regularly seen by fishermen and often rides the bow wave of boats. In spite of this being one of the most common species seen in Fuegian waters, there have been relatively few strandings (Table 1). Perhaps the preference of Peale's dolphin for fiords and deep bays means that sick or dead animals would be broken up on the rocky beaches of southern Fuegia. The Tierra del Fuego collection includes one complete and two nearly com¬ plete skeletons, four good craniums, two very incomplete craniums and two single mandibles. Sci. Rep. Whales Res. Inst., No. 30, 1978. Specimen 649, a female, was caught in robalo nets and retrieved by the fisher¬ men, who covered the carcass with sacks to protect it from the birds until we re- turned one month later. Although it was in an advanced state of decomposition, we were able to discern the color pattern. The other two nearly complete skeletons had already been flensed by birds when found. Peale's dolphin, since it is common in the channels and is inclined to play around boats, is one of the species harpooned for centolla bait (Torres 1977).  Many have probably been captured in the last two years (Sielfeld et al. 1977a, 1977b) but I know personally of only two instances. The skull of an animal harpooned near Puerto Williams in the eastern Beagle Channel on 15 Jan. 1977 is deposited in the Museo Martín Gusinde in Puerto Williams, and another was seen by the crew of the R.V. Hero aboard a crab boat in the western Beagle Channel in July, 1977 (T. D. Goodall, personal communication). The craniums in Table 1 exhibit differences in overall size and cranial width, with specimens 179, 193 and 535 being the smallest, 269 and 649 intermediate and 287 and 291 the largest. Since there are very few differences between the skulls of Lagenorhynchus australis and L. cruciger (Fraser and Noble 1968), all will provisionally be included in Lagenorhynchus australis until further comparisons can be made. Cephalorhynchus commersonii (Lacépède, 1804). Commerson's dolphin, Tonina overa This species, considered one of the most striking in the world, occurs from
No. 30, 1978. Peninsula Valdés, Argentina, to the Strait of Magellan and Tierra del Fuego, the Falkland (Malvinas) Islands, South Georgia and Kerguelen Island (Brownell 1974, Aguayo 1975, Rice 1977). Brownell (1974) shows only two specimens of indefinite locality from Tierra del Fuego and one from the Strait of Magellan. Norris (1968) captured two more specimens in the Strait of Magellan in 1968. Sightings have been made in the Beagle Channel and south of Cape Horn (Olrog 1950, Aguayo 1975). Strange (1972) considered this the most common dolphin off the Falkland (Malvinas) Islands. The opinion of local residents that the Commerson's dolphin is more common in the northern part of Tierra del Fuego than in the southern seems to be con¬ firmed by the collections, most of which are from Bahia San Sebastian (Table 2). Since this is a coastal species (Brownell 1974), one would assume that it would be one of the most likely to be victim to accidental exploitation. J. G. Mead (in Mitchell 1975) found that the Commerson's dolphin was taken incidental to centolla fishing north of Rio Gallegos. He estimated the number taken as less than 20 per year and perhaps 100 per year on the whole coast. The specimens from Tierra del Fuego show a heavy accidental catch. During the 1977-78 season, when fishermen at San Sebastian started saving skeletons for me, eleven fresh animals and 20 skeletons flensed by birds were collected. Three of these were caught in centolla nets and 28 in robalo nets. This does not represent the full catch, as some caught in robalo nets were sent to Ushuaia for crab bait, some lived until the following high tide and were able to swim away, and some carcasses left out on the bay near the nets floated away. The catch in Chilean Fuegia is probably much higher still. Fishermen at Bahia Inutil, using only two of the many boats in the area, estimated a catch of 20-30 per year in their centolla nets. Of the animals of known sex caught by fishermen, there were twice as many males (thirteen) as females (six). Based on fusion of the epiphysis, six very im¬ mature, 12 immature, two subadult and 12 adult or very old animals were caught, appearing to be a fairly relative sample of the local population.  Several of the " immature " specimens showed adult total lengths. During the first week of December, 1977, two pregnant females were caught at the Península Páramo.   One dolphin was born on the beach and the other was removed by the fishermen after the mother died.   Both were sent to Ushuaia for crab bait. When I checked with the company, they had already been used. These two records, confirmed by several fishermen and the director of the centolla factory, along with that of the dolphin (RNP 634) with a near term fetus caught on 12 Dec. 1977, indicate that Cephalorhynchus commersonii calve in early summer. Three other records of Commerson's dolphin, not given in Table 2, can be mentioned.   On 16 Oct. 1972, fishermen left a small female (112 cm) on the beach in Ushuaia. The animal was not preserved, but measurements and drawings were recorded. A Commerson's dolphin, caught by robalo fishermen on 21 May 1976 at Rio Grande, has been mounted and is on display in the Musco Salesiano, Rio Grande. On 28 Jan. 1978, we saw a Commerson carcass, partially flensed by birds, beside a net on the Péninsula Páramo, but could not reach it because of the deep The pigmentation pattern was clearly recognizable. mud. Lissodelphis peronii (Lacépède, 1804) Southern right whale dolphin, Delfín liso This dolphin, mainly on the basis of sightings, seems to be widely distributed around the world in the southern hemisphere (Brownell 1974, Aguayo 1975, Mitchell 1975).  Gaskin (1968) recorded many sightings but no strandings for New Zealand. The known sightings and stranding records for the species are shown by
Sci. Rep. Whales Res. Inst., No. 30, 1978. SMALL CETACEANS OF TIERRA DEL FUEGO
Sci. Rep. Whales Res. Inst., No. 30, 1978. GOODALL
No. 30, 1978. Cephalorhynchus commersonii, lateral view of an adult male (RNP 636) caught in robalo nets at Bahía San Sebastián in December, 1977.   (Photo T. D. Goodall) Brownell (1974), who gives a total of only seven specimens, six from southern South America and one from Tasmania. Of those from South American waters, four were collected well off shore and two were found at Bahia Thetis, Tierra del Fuego. Aguayo (1975) records a live animal caught by fishermen at Concon, Chile, which was later released. The collection now reported includes four nearly complete skeletons, 17 cranial specimens and eight groups of isolated vertebrae. The four nearly complete specimens were found in a mummified state on the mud flats and had been partially flensed by birds. The tips of the flippers and of the upper jaw of RNP 656 had been eaten, probably by a fox ( Dusicyon griseus ).
Sci, Rep. Whales Res. Inst., No. 30, 1978. GOODALL TABLE 3. Continued.
Sci. Reb. Whales Res. Inst., No. 30, 1978. The eleven cranial specimens from the Río San Martín area, all beach worn, may represent a mass stranding. Most sightings of the southern right whale dolphin have been well offshore (Brownell 1974) and it has generally been considered pelagic (Mitchell 1975) or pelagic and coastal (Aguayo 1975). The collections from Bahía San Sebastián and the two specimens found well within the Beagle Channel (Cutalátaca and Gable Island), indicate that it may occasionally inhabit shallow waters.
Globicephala melaena (Traill  1809)
Long-finned pilot whale, Piloto, Calderon The long-finned pilot whale is common throughout the Southern Ocean north of the Antarctic Convergence but associated with cold currents. There is a distinct population in the North Atlantic Ocean. Specimens are known from all shores of the southern continents and larger islands (Mitchell 1975, Brownell 1974). Brownell (1974) cites 13 specimens from southern waters, including one from Isla de los Estados. Pifiero and Castello (1975) summarize South Atlantic mass strand- ings from Uruguay, the Falkland (Malvinas) Islands and Bahía Blanca, Argentina. The only specimens they cite from Tierra del Fuego were parts of eleven animals collected by Norris from Isla Navarino in 1968. Pilot whale strandings are common on Tierra del Fuego beaches. Strandings from which specimens were collected (worn material was not collected) are given in Table 4. Skeletons which were left on the beach to be collected later, because of their weight and state of decomposition, are indicated in parenthesis. In December, 1966, two pilot whales (RNP 1 and 2) were found stuck in the mud of the First West Creek, Estancia Harberton.  Although they lived for two days, there was no way to free them. Both skeletons (434 and 410 cm long re¬ spectively) are preserved at Estancia Harberton. Several other Fuegian strandings of pilot whales are known. Eleven animals stranded south of the Estancia Viamonte houses in 1928 or 1929 (T. L. Bridges, personal communication).  RNP numbers 21, 27 and 31 may represent part of this stranding, since bones are shifted northward by the rising tide. On 7 November, 1971, while on a botanical expedition aboard the R.V. Hero to Isla de los Estados, T. R. Dudley and I saw and photographed a mass stranding of nine pilot whales in Bahia Flinders. Because of their semi-decomposed con¬ dition, no specimens were collected. One pilot whale cranium, without data, is on exhibit at the Museo Salesiano in Río Grande, and there are others in Fuegian private homes. The specimens collected at Cabo Irigoyen and Estancia Fueguina (Table 4) represent cranial material from 17 animals. These were part of a mass killing by depth charges of 27 adult and 12 young pilot whales in 1972. The animals came ashore at Estancia Irigoyen, then washed north beyond Cabo Irigoyen and on to Estancia Fueguina (Nemesio Menendez, personal communication, 1977). GOODALL TABLE 4.  TIERRA DEL FUEGO STRANDINGS OF GLOBICEPHALA MELAENA
Orcinus orca (Linnacus, 1758) Killer whale, Orca Killer whales are found in all oceans, but are most abundant in cold waters of both hemispheres (Brownell 1974, Mitchell 1975, Rice 1977). Although com¬ mon, very few specimens are known from the southern hemisphere (below 35°S). Gaskin (1968) records various strandings for New Zealand, but listed only four specimens. Brownell (1974) shows five specimens, including three of those cited by Gaskin. Strandings of killer whales are common on Fuegian beaches. Because of their size and state of decomposition (usually still held together by very hard, dry meat and skin), most of the specimens listed below (Table 5) have been numbered and left on the beach. Certain bones have been collected as they come loose. Sci. Rep. Whales Res. Inst., No. 30, 1978. TABLE 5. STRANDINGS OF ORCINUS ORCA. SPECIMENS IN PARENTHESIS HAVE NOT YET BEEN COLLECTED, BUT WERE NUMBERED ON THE BEACH
Four killer whales (RNP 612, 672, 673 and 674) were stranded together on the San Sebastian mud flats in November, 1972. I first saw them in 1975 and have These animals are visited the location several times a year since then (Fig. 8). about one km out from shore on the mud and have been " mummified " by the Sci. Rep. Whales Res. Inst., No. 30, 1978. salt water which reaches them on the very highest tides. The skin and meat have gradually decayed away on the under side, leaving the skeleton with an upper tough, lichen encrusted covering. Along the outer edge of vegetation bordering the salt flats at the west side of Bahía San Sebastián, a series of 15 nearly complete orca skeletons are spread over a distance of about eight kilometers (Fig. 9).   All are about the same stage of de- composition, almost surely representing a mass stranding, probably a little earlier than the four '' mummified '' whales farther north.  Many of these have been damaged by people chopping at the jaws, trying to remove the teeth.
FAMILY  PHOCOENIDAE
Phocoena spinipinnis Burmeister, 1865 Burmeister's porpoise, Black porpoise, Marsopa espinosa Fraser (1948) calls this porpoise a rarely occuring species. Aguayo (1975) shows its distribution in Chile as reaching south to Valdivia (40°S). It seems to be fairly common in northern Chile and Peru, where it is taken for food (Mitchell 1975, Anonymous 1975). On the Atlantic coast, this porpoise has been cited for Uruguay (Praderi 1971, Pilleri and Gihr 1972, 1974) and southward to Patagonia (Praderi 1971).  Rice (1977) summarizes, " East coast of South America from Uruguay to Patagonia ; west coast from Paita, Peru, to Valdivia, Chile." Pilleri and Gihr (1972) illustrated the species as occurring all the way from Uruguay around Cape Horn to Peru, but Brownell and Praderi (1975) rightly felt that this was not valid, since no sightings nor specimens for the species existed as far south as the Strait of Magellan. They thought that the Atlantic and Pacific populations might be isolated. Praderi (1971) mentions Few museum specimens are known of this species. The specimens represented in Table 6 are the southernmost known only eight. and the first from the Cape Horn area. Specimens 110 and 111 were taken in centolla nets. On 3 Dec. 1975, another
No. 30, 1978. Burmeister's porpoise was caught in the nets in Lapataia Bay, Beagle Channel. The fishermen, who threw it overboard, estimated it to be about 160 cm in length. Specimen 167 was found on the beach to the east of Ushuaia ; it also may have been caught in crab nets. Although very fresh, it had been eaten by dogs and the sex could not be determined. The collection of these specimens in Tierra del Fuego indicates that Phocoena spinipinnis may occur continuously around southern South America from Uruguay to Peru.  Further studies are needed in the area south of 40°S.
Phocoena dioptrica Lahille, 1912
Spectacled porpoise, Marsopa de anteojos Praderi (1971) and Brownell (1975), who gave the most complete accounts of this species, listed only ten specimens (one a fetus) and one stranding observation, all from the western South Atlantic. The type specimen presumably has been lost. The collection of a skull in January, 1974, from New Zealand (Baker 1977, Caw¬ thorne 1977) greatly extended the known distribution. The range of this cetacean can now be considered to include the western South Atlantic coast from Uruguay to Tierra del Fuego, the Falkland (Malvinas) Islands, South Georgia and New Zealand (Baker 1977). The species has been sighted alive only near New Zealand (M. Cawthorn, personal communication 1977) although a possible sighting has been reported from Kerguelen (Frost and Best 1976), which could indicate a circum polar distribution around off shore islands. This work presents eleven fairly complete skeletons, 76 complete or partial skulls and 25 groups of vertebrae. A further 29 post-cranial specimens from the collection, containing from one to 44 vertebrae, have not been included. Total lengths are available for only six of the eleven most complete specimens. Due to the state of decomposition, pigmentation was discernable on only four occasions (RNP 412, 413, 658 and 670). Specimen 670 was fresh and has been
Sci. Rep. Whales Res. Inst.,
No. 30, 1978.
preserved entire in formol.   Dorsal fin tracings were taken from five animals. Two specimens, RNP 413 and 670, probably unweaned animals since denti- tion had not erupted, were found in mid-February and late March.  The only other reproductive data known for the species was that of two pregnant females with near term fetuses obtained in late July and mid-August (Brownell 1975). The finding of two suckling animals in late summer seems to confirm that young may be born in late winter or early spring. Only one of the specimens (RNP 412) was definitely known to have been taken accidentally (in a robalo net).  Specimen 413 was presumably its calf and probably died after the mother was caught. Both were found in advanced stages of decomposition. Another specimen (670) had been deliberately wounded and its mother could not be found.  It lived for three hours and observations were made of it swimming in Harberton Bay.   No other specimen has been collected alive (Anony- mous 1975). This is the only specimen from southern Tierra del Fuego. In view of these numerous beach collections, Phocoena dioptrica appears to be the small cetacean most common in the waters off northeastern Tierra del Fuego, yet there are no published observations of live animals in this area (Brownell 1974). The collection of the majority of these specimens from Bahia San Sebastian and one from the Beagle Channel seem to indicate that it is an inshore species.
Sci. Rep. Whales Res. Inst., No. 30, 1978. GOODALL'
No. 30, 1978. SMALL CETACEANS OF TIERRA DEL FUEGO
No. 30, 1978.
FAMILY  ZIPHIIDAE
Tasmacetus shepherdi Oliver, 1937 Shepherd's beaked whale, Tasman whale This rare whale is known from eight stranded specimens (Mitchell 1975, Anonymous 1975). Six specimens are known from mainland New Zealand, Steward and Chatham Islands (Oliver 1937, Gaskin 1968), one from Peninsula Valdés, Argentina (Mead and Payne 1975) and a photographed but not collected stranding on the Islas Juan Fernandez, Chile (Brownell et al. 1976). The collection of two specimens on Tierra del Fuego extends the known distribution southward and furthers the assumption (Anonymous 1975) that the species is circumpolar.
Cranium The collections in Table 8 were made in unusual circumstances. Cervicals RNP 582 was found leaning against a new fence 200 m from the beach. RNP 457 appear to belong to this cranium as they were found on the same beach and match the condyles. Both have the same degree of beach damage. In April, 1977, a very worn cranium was photographed at the Prefectura Maritima Station on Gable Island. In March, 1978, a set of mandibles that had been decorating the wall of an Ushuaia restaurant for two years were examined Sci. Rep. Whales Res. Inst., No. 30, 1978. and found to be those of a Tasmacetus (RNP 666). The measurements agree very closely with those given by Oliver (1937). Further inquiry yielded an approxi¬ mate date (1974) and the site of collection; a trip was made to retrieve that which remained (cervicals, 18 additional vertebrae, right scapula, two ribs, two radii, one humerus and a section of sternum). It was confirmed that the cranium and mandible came from the same animal. I have been unable to obtain the cranium for study. Berardius arnuxii Duvernoy, 1851 Arnoux's beaked whale Brownell (1974) gives the distribution of this whale as South Australia, New Zealand, South Africa, Argentina, the Falklands (Malvinas), South Georgia, the South Shetlands and the Antarctic Peninsula, showing a total of 14 specimens. McCann (1975) records more specimens, mainly from New Zealand. The only specimen known from the continental coasts of the western South Atlantic is from the Rio de la Plata, Argentina (Marelli 1920). There are no former records from Tierra del Fuego. Sci. Rep. Whales Res. Inst., No. 30, 1978.
TABLE 9.  NEW SPECIMENS OF BERARDIUS ARNUXII
Berardius arnuxii, dorsal aspect of a very incomplete and beach damaged Fig. 14. cranium, RNP 693, found north of Punta Maria in March, 1977. (Photo I.S. Cameron) The new specimens from Tierra del Fuego are two groups of cervical vertebrae and a very worn, incomplete cranium. Specimen 566 from the Rio Marazzi, Inutil, has the centrae and neural arches of the first three cervicals fused and the fourth fused by the neural arch. The first three cervicals of number 472 are fused. The partial cranium, RNP 693, was photographed on the beach in March, 1977, but because of weight it was not collected until May, 1978. Mesoplodon layardii (Gray, 1865) Strap-toothed whale, Layard's beaked whale This species is known from New Zealand, southern Australia, South Africa, the Falkland (Malvinas) Islands (Turner 1880, Fraser 1948, Rice 1977) and from Uruguay (Praderi 1972). Gaskin (1968) records 19 specimens from New Zealand. Until now there was no record from Tierra del Fuego. Five new crania were found on Tierra del Fuego, four from Bahia San Seba¬ stian and one from the Beagle Channel. Unfortunately, no complete mandibles were, found. Specimen RNP 61 was stranded between April and July, 1974. The body had been burnt and only 14 vertebrae and the cranium were recovered. Ziphioid vertebrae are frequently scattered on the beaches, but positive Sci. Rep. Whales Res. Inst., No. 30, 1978.
identification is difficult due to beach damage. Mesoplodon grayi von Haast, 1876. Gray's beaked whale, Scamperdown whale Rice (1977) cited Gray's beaked whale from South Africa, South Australia, New Zealand, Chatham Island, and Argentina, as well as one record from the Netherlands. The species appears to be most common near New Zealand (Gaskin 1968). The western South Atlantic specimens are all from Argentina ; Quequen, Monte Hermoso and Miramar in the Province of Buenos Aires (Urquiola et al. 1970) and Chubut (Moreno 1895). There are no former records from Tierra del Fuego. New records for this species (Table 11) include one nearly complete skeleton, three crania and one group of thoracic vertebrae. Specimen RNP 270 is nearly complete (lacking scapulae and flippers). It was an adult animal with a total length of 516 cm. The total length of the skeleton is 463 cm. The teeth were visible in the lower jaw, indicating a male, and there were 15 vestigial teeth embedded in the flesh of the upper left and nine in the upper right jaw. The animal was in a very decomposed condition when found. The other three crania are incomplete ; two of them are very beach worn,
cranium and mandibles of RNP 172, found in December, 1975, on the mud flats of western Bahia San Sebastian.   (Photo T. D.
Mesoplodon hectori (Gray, 1871)
Hector's beaked whale Hector's beaked whale is known only from Tasmania, New Zealand, the Falkland (Malvinas) Islands and South Africa (Rice 1977). In the literature there are only six specimens published (Ross 1970). The only specimen known from American waters is that from the Malvinas (Fraser 1950, Hamilton 1952). RNP 172 becomes the seventh known animal of this species and the first Sci. Rep. Whales Res. Inst., No. 30, 1978.
TABLE 12.  NEW SPECIMEN OF MESOPLODON HECTORI RNP no. 172
from Tierra del Fuego, in addition to being the southernmost specimen yet found. When found on the west side of the San Sebastián mud flats on 21 December, 1975, this animal was well decomposed. The head and rib cage were taken at that time, while the rest of the animal was collected in February, 1976.  This specimen is of a young animal and is complete except for the scapulae, flippers and part of the sternum. The neural spines of three vertebrae are damaged. None of the vertebrae are anchylosed, but two well-developed teeth are present, indicating that it was a male. The total length of the skeleton is 281 cm.
Ziphius cavirostris G. Cuvier, 1823
Cuvier's beaked whale, Ballena picuda de Cuvier This whale is cosmopolitan, occurring in all oceans, except at high latitudes. A number of specimens are known from around the world, as far south as Tierra del Fuego (Anonymous 1975, Mitchell 1975, Gaskin 1968). Eight new records are reported in Table 13 from Tierra del Fuego. An adult male Cuvier's beaked whale (RNP 3) was stranded entire at the First West Creek, Estancia Harberton, in September, 1967. The cause of death The pigmentation pattern was visible and the body was covered was unknown. with parallel scratches.  With the exception of the blubber, birds showed little interest in it, although one wintery day nearly a year after stranding, six condors (Vultur gryphus) were seen sitting on it. This specimen took five years to decay. Both teeth were present on stranding, but one disappeared before it could be The nearly complete skeleton is preserved at Harberton. collected. Number 327 is a male skull in excellent condition. One tooth was missing. The other six skulls are incomplete and very beach worn. The male specimens were so classified because of the pronounced " basining " of the cranium. Speci- men 138 is a complete vertebral column without a skull.
Sci. Rep. Whales Res. Inst., No. 30, 1978. Hyperoodon planifrons Flower, 1882 Southern bottlenose whale, Ballena pico de botella The southern bottlenose is widely distributed in the southern hemisphere. Specimens are known from New Zealand, Australia, South Africa, the South Atlantic Islands and off the coast of Antarctica (Brownell 1974, Rice 1977). In South America the species is known for southern Brazil, Argentina (Gianuca and Castello 1976), the Falkland (Malvinas) Islands (Hamilton 1952), South Georgia and the South Orkney Islands (Fraser 1945), and the Chilean coast (Clarke 1962). None were known from Tierra del Fuego until the following speci¬
Sci. Rep. Whales Res. Inst., No. 30, 1978. mens were found. Four crania and a group of seven fused cervicals represent the collection in Tierra del Fuego.  Only one of the crania, found at Estancia Harberton on the Beagle Channel, is in fair condition. The others are very broken and beach worn. Specimens 382 and 585 were buried in sand and mud, respectively, and crumbled extensively on removal. The latter specimen has mandibles but no teeth; the mandibles have also disintegrated on drying. No fresh specimens were found.
DISCUSSION
Because of the enormous amounts of water and few inhabited areas, the small cetaceans of the Southern Ocean are little known.  Museum specimens of southern whales and dolphins are few, and even less were known from Tierra del Fuego, where  little previous work has been done. Recent combing of the beaches has produced large quantities of new cetacean material. The area where most specimens were found was Bahia San Scbastian, but all beaches sampled offered a few specimens. Only a small portion of available beaches were checked. Southern Patagonia and Tierra del Fuego offer extensive beaches, many of which have never been surveyed. Since most of the specimens had been on the beach for long periods, I have little information on the seasonality of strandings, but a systematic checking of beaches should yield new data. The slow rate of decay makes it difficult to judge the length of time the animals have been on the beach. Eight of the fourteen species (Orcinus orca, Phocoena spinipinnis, Tasmacetus shepherdi, Berardius arnuxii, Mesoplodon layardii, M. grayi, M. hectori and Hyperoodon planifrons) had not been previously collected on Tierra del Fuego, although most of them were known for the general area. It is strange that deepwater species such as Lissodelphis peronii, Tasmacelus shepherdi, Mesoplodon layardii, and Hyperoodon planifrons should be found in the rela¬ tively shallow waters north of Gable Island in the Beagle Channel and the very shallow waters of Bahía San Sebastián.  Mitchell and Kozicki (1975) mention that Hyperoodon ampullatus is known to stray into fiords and rivers during migra- tions and then strand. This may be the case here. In number of cranial specimens (91) Cephalorhynchus commersonii was the species most often collected, but this total includes a large number (at least 31) which were taken in fishing nets.   The species most numerous in strandings was Phocoena dioptrica (88 cranial and many post cranial collections), which was thought to be one of the rarest cetaceans.  More study on these and other species occuring in the area is needed. Means should be found to protect the southern dolphins from deliberate exploitation for crab bait and accidental capture in fish nets.  Little is known of the populations of the two species most affected, Lagenorhynchus australis in the chan- nels and Cephalorhynchus commersonii in the Strait of Magellan, its bays and the Atlantic coast, but it is doubtful if either are able to withstand much exploitation. My future plans include periodic surveys of the beaches which have yielded the most material, exploration of new beaches, and more study of the dolphins captured incidentally during robalo fishing at Bahía San Sebastián.
ACKNOWLEDGMENTS
I wish to express my thanks to the many people who assisted in the aquisition of this collection. H. P. Castello, R. Brizuela, A. J. Goodall, C.M.B. Goodall, G. Currie, D. McNeil, S. Harvey, A. Wanamaker, A. Hanson and others helped comb beaches and/or clean specimens.   D. Scully, D. Paramlee and J. Fell assisted in the dissection of some of the fresh animals. One or more specimens were donated or loaned by N. O'Byrne, J. Lawrence, R. Scotti, J. Torres, J. Tico, S. Gonzalez and the fishermen of Ushuaia, San Seba- stian and Bahía Inútil.  J. C. Antunovich, head of the fishing company at San Sebastián, was very helpful. The Prefectura Maritima and the Policia Territorial gave me every considera- tion, while the Pesquera del Beagle S. A. and the Base Naval Ushuaia kept frozen specimens.  Laboratory space on one expedition was loaned by the Instituto de la Patagonia in Punta Arenas. Hospitality was extended by Estancias Harberton, Viamonte, Pirinaica and Cullen, and by Bridas S.A.P.I.C. 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