Eubalaena australis (Desmoulins, 1822)

Russell A. Mittermeier & Don E. Wilson, 2014, Balaenidae, Handbook of the Mammals of the World – Volume 4 Sea Mammals, Barcelona: Lynx Edicions, pp. 186-215 : 211-212

3.

Southern Right Whale

Eubalaena australis

French: Baleine australe / German: Slidkaper / Spanish: Ballena franca austral

Taxonomy. Balaena australis Desmoulins, 1822 ,

“les baies d’Algoa, du Cap” (= Algoa Bay, Cape of Good Hope, South Africa) .

This species is monotypic.

Distribution. Cold-temperate waters of the Southern Hemisphere, mainly at 20-60° S except on both coasts of South America, where they occur at most lower latitudes. Concentrated in winter near the coastlines off S Australia, New Zealand, Atlantic coast of South America (Argentina, Brazil), and S Africa (mainly South Africa), but also off Chile, Peru, Tristan da Cunha Is and the E coast of Madagascar; in summer they are found mainly in latitudes of 40-50° S but have been seen in the Antarctic as far as 65° S and around South Georgia Is.

Descriptive notes. Total length 1500-1650 cm; weight to ¢.60,000 kg. Like other species of Fubalaena, the Southern Right Whale is massive and stocky, with an extremely large head. Although Southern Right Whales are generally black, they have white patches ventrally on tip of lowerjaws and abdominal region. These areas may be more extensive on Southern Right Whales than on their congeners. Pale grayish area may be visible on backs of a few individuals. Southern Right Whales can have a whitened or pale gray mottled appearance caused by sloughing of skin. Variations in the overall black color have been observed, with some individuals having a bluish or brown coloration. There is no dorsal fin or ridge on the wide, smooth back. Flipper length is up to 170 cm. Flukes are wide and taper gently to smooth trailing edges. There are on average 222 baleen plates that range from gray to black, with a maximum length of 240 cm, and have fine fringes. Callosities on Southern Right Whales are prevalent and broadly dispersed on head and rostral region; they frequently occur along top of lower jaw. Males have more callosities than females. It has been suggested that callosities are used aggressively in male-male competition for females. Differences in patterns of callosities are used to identify individuals in photo-identification research of Southern Right Whales. In addition to cyamids that inhabit callosities of all species of right whale, barnacles (Tubinicella major) occur in callosities of Southern Right Whales.

Habitat. Feeding grounds of Southern Right Whales are not well known. In the southern Atlantic Ocean, they may be mainly offshore, and in Antarctic waters, they are also apparently predominately offshore. As with other species of right whales, feeding grounds of Southern Right Whales are likely to be areas of extremely high productivity and prey abundance. Most of the relatively few offshore sightings indicate individuals may occupy areas within the subtropical and Antarctic convergences. Sheltered, shallow waters and bays in many coastal areas are used to give birth. These birthing grounds include areas off Argentina, Brazil, Tristan da Cunha, Namibia, South Africa, Mozambique, Australia, New Zealand, Auckland Islands, and Chile.

Food and Feeding. Southern Right Whales are skim feeders, using their long, finely bristled baleen to filter prey from the water at the surface and below. Both copepods and krill are important in their diets. Euphausiids, including euphausiid krill (Euphausia superba) and squat lobster (Munida spp.), form a larger part of diets of Southern Right Whales than those of North Atlantic Right Whales ( E. glacialis ) and North Pacific Right Whales ( E. japonica ). When feeding north of the subtropical convergence, Southern Right Whales are likely to feed mainly on copepods, but they also feed on euphausiid krill within the Antarctic Convergence where krill predominates. Interestingly, whaling data reflected this pattern: 91-7% of whales north of 40° S had fed on copepods (mainly Calanus propinquus and Pleuromamma robusta), whereas more than 99% of whales south of 50° S had euphausiids in their stomachs.

Breeding. Average age offirst birth for female Southern Right Whales is at 9-12 years, when females are more than 1200 cm in length. Gestation is 12-13 months. Birth interval is typically about three years but may be as long as five years when prey availability is limited. Births occur in June—-October, with a peak in late August. Neonatal length is 450-600 cm. Weaning is at a minimum of 7-8 months but can be extended to 12-14 months. Breeding is thought to mainly occur from June to September, but like North Atlantic Right Whales, mating of Southern Right Whales has been observed throughout the year. Southern Right Whales are known to aggregate in large surface-active groups where males appear to compete for a single female—as is also similar to North Atlantic Right Whales. Mating has been observed on and around birthing grounds, but some segregation is likely between breeding adults and female—offspring pairs.

Activity patterns. Like their congeners, Southern Right Whales are slow moving, often resting or logging at the surface. They are also often observed breaching and engaging in other active behaviors at the water’s surface, including flipper slapping and lobtailing. Southern Right Whales in Argentina and South Africa use their flukes as sails at the water’s surface, letting the wind glide them through the water for short distances. Tactile behavior—touching and rubbing conspecifics—has also been observed in Southern Right Whales.

Movements, Home range and Social organization. Southern Right Whales migrate northward to coastal areas for the austral winter. In summer, they move southward, presumably to more offshore areas. Recent satellite-tagging research was conducted in September-December 2001 at Saint Sebastian Bay and Saldanha Bay, South Africa. Results from tagging were combined with information based on photo-identification, aerial surveys, and historical catch records to provide insight into movements of Southern Right Whales in that region. Fifteen individuals were tracked for 25-161 days. Nine whales remained along the coastline (four females with offspring, three unaccompanied females, one male, and one of undetermined sex), and movements (although not always unidirectional) were primarily westward. Movements of female—offspring pairs were generally slower that those of other classes. Four of the nine whales remaining in coastal areas moved to Saint Helena Bay, which was likely a feeding ground, and stayed there for 36-100 days. Six individuals moved offshore; one could not be tracked subsequent to its departure, and five (three males, one female, one of undetermined sex) moved, independently, heading south-west into the South Atlantic Ocean, covering distances of 3800-8200 km. These five individuals were considered to be migrating. Speeds for these individuals were 0-6-2-8 km/h. Two areas were possible feeding grounds because of the non-directionality of movements while the whales traversed the areas. Each of the five whales moved into the South Atlantic Ocean where their transmitters eventually stopped. There have been limited sightings of Southern Right Whales in Antarctic waters during summer. Away from aggregation sites, Southern Right Whales are often found alone or in small numbers.

Status and Conservation. CITES Appendix I. Classified as Least Concern on The IUCN Red List, with the Peru—Chile subpopulation of the Southern Right Whale classified as Critically Endangered. Moving clockwise from the western South Atlantic Ocean, Southern Right Whales are found from May through December in coastal waters off Brazil, from ¢.8-32° S (mainly 27-29° S) to Uruguay and south to central Argentina (mainly around Valdes Peninsula) and south to Cabo Virgenes (52° 19° S) and into the Straits of Magellan and the Beagle Channel. In the mid-South Atlantic Ocean, they are found around Tristan da Cunha (c.38° S, 12° E). In the eastern South Atlantic Ocean, Southern Right Whales are found in the north off the Namibian/Angolan coast (c.16—-27° S), with the majority found between 18° 30” S and 21° 30’ S, and then south to South Africa between Saint Helena Bay in the west and Port Elizabeth to the east. In the south-western Indian Ocean, they are in waters off Mozambique and Madagascar. Off western Australia in the eastern Indian Ocean, Southern Right Whales occurin the north at least as far as Exmouth (c.22° S, 114° E), but most are found between Cape Leeuwin, Western Australia (32° 33° S, 115° 08 E) and Ceduna, South Australia (32° 08’ S, 133° 41" E). In the south-western Pacific Ocean, they were known from the coastal waters around New Zealand and the Kermadec Islands (29° S, 178° W), where they are now absent. There are some recent records of Southern Right Whales reestablishing former wintering grounds off mainland New Zealand. Southern Right Whales are found near the Auckland Islands during austral winter and in North-west Bay, Campbell Island, in February-September. In the eastern South Pacific Ocean, the few remaining Southern Right Whales are known from Bahia San Fernando, Peru (15° 08S) in the north, southward to at least Isla Grande de Chiloe, Chile (42° S), but they are more commonly observed around Isla Grande de Chile, Chile. The bestknown feeding areas of the Southern Right Whales are around the Falkland Islands and South Georgia (February—May), the Antarctic Peninsula, and below 40° S off Australia. In the Indian Ocean, they are known from the Crozet Islands (c.46° S, 51° E) and Kerguelen Islands. In 1997, the total population of the Southern Right Whale was ¢.7600 individuals in the three ocean basins of the Southern Hemisphere. The Southern Right Whale has long been widely recognized as having had been over-utilized and depleted by commercial hunting during the late 18" 19"and early 20" centuries— hunting that only ended in the 1930s. During the 200 years between the start of commercial whaling for the Southern Right Whale in the 1770s and complete cessation in the early 1970s, total catch was ¢.115,000 individuals. Combined catches within each of the three ocean basins were ¢.63,000 individuals in the South Atlantic, 38,000 in the South Pacific, and 13,000 in the Indian Ocean. This included more than 3300 Southern Right Whales taken illegally during Soviet pelagic whaling operations, mainly in the 1960s. Based on a model used at the International Whaling Commission (IWC) 1998 Right Whale Workshop, the initial abundance of Southern Right Whales in 1770 was estimated at ¢.55,000-70,000 individuals. After human exploitation ceased, most populations of Southern Right Whales began to increase. Total population size was estimated at ¢.7600 individuals in 1997, and the population model used to make this estimate suggested a current annual growth rate of 7-5%, although this rate of increase may have slowed in recent years. No current population assessmentis available. The Brazil-Argentina population of the Southern Right Whale in Argentine waters was estimated at 2577 individuals in 1997. In waters off Argentina, the population had been increasing 6-8-7-6% /year since the early 1970s, butthis rate is now slowing to ¢.6%/ year. Since 2003 when the Southern Right Whale Monitoring Program was established in the region of Valdes Peninsula, Argentina, 366 whale deaths have been recorded; number of dead individuals per year was 31 in 2003, 47 in 2005, 83 in 2007, 95 in 2008, and 79 in 2009, with more than 90% of the deaths being young born in those years. Causes of these annual die-offs remain unknown, but a workshop in 2010 agreed on three likely hypotheses (or some combination of them): (1) reduced food availability for adult females, (2) acute or chronic toxicity resulting from exposure to biotoxins, and (3) infectious disease. As of October 2012, another large die-off was underway. In breeding areas around Valdes Peninsula, kelp gulls (Larus dominicanus) feed by pecking on skin and blubber on backs of Southern Right Whales. This gull harassment has increased since it was first documented in 1972, and extensive wounding is now sometimes observed on backs of Southern Right Whales, frequently on female—offspring pairs. It has been suggested that gull attacks could negatively affect the population of Southern Right Whales via disruption to female—offspring pairs and potential transmission of pathogens and infectious diseases. A subsequent workshop, convened in 2013, concluded that the increasing frequency of gull attacks, including concomitant increases in physical and behavioral disturbance to Southern Right Whales, has reached a threshold level in recent years above which these factors may induce death in some Southern Right Whale offspring, leading to the high levels of mortality recorded since 2005. In South African waters, the population of the Southern Right Whale was estimated at 3104 individuals in 1997. In 2008, the population estimate had only increased to 3612 individuals. There has not been any die-off in this area, but entanglementin fishing gearis ¢.3:5% /year. The Australian population of the Southern Right Whale was estimated at 1197 individuals in 1997. In 2009, the best estimate in Australia between Cape Leeuwin and Ceduna was 2900 individuals. Based on photoidentification, genetic samples, and mark-recapture methods comparing winter surveys between 1995-1997 and 2006-2009, number of Southern Right Whales off the Auckland Islands was estimated at a minimum of 2306 individuals. The Peru—Chile subpopulation of the Southern Right Whale likely has fewer than 50 individuals remaining. No pre-whaling population estimate is available, but it is known that French vessels alone killed an estimated 2372 Southern Right Whales in Chilean waters in 1817-1837. Mortalities of South Right Whales due to entanglements in fishing gear and collisions with ships are known throughout the Southern Hemisphere, and human activities in Chile caused at least two whale deaths: one was a young individual harpooned by fishermen and the other was a young that stranded after being struck by a vessel. Any human-caused mortality, especially females, in this subpopulation is a serious issue. Vessel strikes and fishing gear entanglement of Southern Right Whales are rare compared with the number of cases known for North Atlantic Right Whales. In Australia, there are at least four cases of entanglementin fishing gear in 1991-1997. In other parts of the Southern Hemisphere, known fishing-gear entanglements include the following: at least 14 entanglements in South Africa in 1963-1997; two in the Auckland Islands in 1995-1997; seven in Argentina in 1969-1997; approximately four per year in Santa Catarina, Brazil, in 1989-1997; three along the San Paulo coast, Brazil, in 1982-1996; and three off Rio de Janeiro in 1981-1992. Southern Right Whales killed or injured by vessel collisions are known from South Africa and Brazil. Thirteen collisions, ten of which were fatal, occurred off South Africa in 1983-1997, and four collisions, at least three fatal, occurred off Brazil in 1989-1993. Collisions with large vessels are of concern for Southern Right Whales around Australia, particularly on shipping routes on the eastern seaboard near the Bass Strait. Numbers of vessel strikes and gear entanglements are too small in relation to current population sizes to impede continued population growth and recovery of populations of Southern Right Whales, except for the Peru—Chile subpopulation. Disturbance and displacement caused by ship noise are threats to Southern Right Whales, perhaps especially in feeding and birthing grounds, and they could potentially disrupt important social activities including breeding. Harassment from whale watching and boaters also potentially present a threat. Prey depletion caused by overfishing of krill and habitat degradation may impact populations of Southern Right Whales. Potential effects of climate change on krill (E. superba) abundance, and thus ability of Southern Right Whales to feed on this prey, could impact their continued recovery.

Bibliography. Aguayo et al. (1992), Bannister, Kemper & Warneke (1996), Bannister, Pastene & Burnell (1999), Best (1990, 1994, 2007), Best & Schell (1996), Best & Underhill (1990), Best, Brandao & Butterworth (2001), Best, Payne et al. (1993), Best, Schaeff et al. (2003), Canto et al. (1991), Carroll, Childerhouse et al. (2012), Carroll, Rayment et al. (2014), Cooke et al. (2001, 2003), Donnelly (1967), Du Pasquier (1986), Elwen & Best (2004a, 2004b), Fazio et al. (2012), Galletti Vernazzani et al. (2013), Hamner et al. (1988), IWC (2001b, 2011, 2012, 2013), Kemper et al. (2008), Kenney (2009), Leaper et al. (2006), Mate et al. (2011), Patenaude (2000, 2003), Patenaude et al. (2001), Payne (1986, 1995), Payne & Dorsey (1983), Payne, Brazier et al. (1983), Payne, Rowntree et al. (1990), Reeves & Kenney (2003), Reilly et al. (2008k), Richardson et al. (2012), Rowntree (1996), Rowntree, McGuiness et al. (1998), Rowntree, Payne & Schell (2011), Scarff (1986b), Sironi et al. (2012), Thomas et al. (2013), Tormosov et al. (1998), Valenzuela et al. (2009).

Figures

1. North Atlantic Right Whale (Eubalaena glacialis), 2. North Pacific Right Whale (Fubalaena japonica), 3. Southern Right Whale (Fubalaena australis), 4. Bowhead Whale (Balaena mysticetus)

Distribution. Cold-temperate waters of the Southern Hemisphere, mainly at 20-60° S except on both coasts of South America, where they occur at most lower latitudes. Concentrated in winter near the coastlines off S Australia, New Zealand, Atlantic coast of South America (Argentina, Brazil), and S Africa (mainly South Africa), but also off Chile, Peru, Tristan da Cunha Is and the E coast of Madagascar; in summer they are found mainly in latitudes of 40-50° S but have been seen in the Antarctic as far as 65° S and around South Georgia Is.