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    HUMPBACK WHALEHUMPBACK WHALE - Megaptera novaeangliae
 Identification: Humpback whales have distendable throat grooves and are therefore classed as rorquals (family Balaenopteridae). They are however, significantly different in appearance and biology to all the other rorqual species and as such, represent a separate, single species genus - Megaptera. Humpback whales have a small dorsal fin about two thirds of the way down the body, which is set upon a gradually sloping hump - more noticeable when the animal dives. Most distinctively however, are the unusually long, often white, pectoral fins, in stark contrast against the almost black upper body. These pectorals can be as much as one third of the total body length and provide the scientific name - Megaptera meaning large wing. The underside of the fluke also tends to be white and the distinct patternation on individual animals can be used by scientists for identification. On the large head are three rows of tubercles, known to the old whalers as "stovebolts". These are also found on the lower jaw and accumulate at it's tip. Humpback whales as large as 18m have been recorded although specimens in the southern hemisphere tend to be smaller.
Biology: Females reach sexual maturity at about 12 meters and like all baleen whales they tend to be larger than the males of equivalent age. Gestation lasts between 11 and 12 months and generally produces a single calf which is then suckled for a period of 10 to 11 months.
Behaviour: Southern ocean stocks of humpback whales feed almost exclusively on krill near the polar regions and are known to create bubble nets in order to concentrate their prey. Sightings in South Africa are not unusual from June to Janurary as the whales migrate up the east coast to calve and mate in the waters off Mozambique and Madagascar. Although humpback whales appear not to feed when in tropical waters, it is believed they may feed opportunistically on the journey back to Antarctic regions. During this period the whales are merely passing our coastline but we often find them offshore in small groups (of upto 10 animals) or singly and with calves.
Humpback whales are able to launch their entire body clear of the water and have been recorded breaching over 100 times in succession. They are also the most 'vocal' of all whales and if you dive in South Africa during the winter months you may well hear the haunting songs of the humpback whale, although the animals themselves can be several kilometers away. Only the males sing long, elaborate, songs which can last up to 20 minutes and may be repeated for several hours at a time. Research has shown that these songs, which are gradually modified over time, are learnt and passed on to other whales within specific populations - an example of whale culture similar to that in evidence amongst many species of toothed whale.
SOUTHERN RIGHT WHALESOUTHERN RIGHT WHALE - Eubalaena australis
 Identification: Southern right whales have no dorsal fin. The large rotund body, attaining 16m and a weight of 65 tonnes, is mostly black with some individuals appearing mottled. The mouth of the southern right whale describes a high arch and the head bears numerous warty growths known as callosities. These growths form a unique patternation amongst individuals and are a useful means of identification. Southern right whales have a distinctive blow and can be immediately recognised from the surface by their V-shaped spout upon exhalation.
Biology: Southern right whales are biologically very similar to their northern cousins, the... wait for it... northern right whales. Competition between males is non-agressive as several males will mate with the female and fertilisation is achieved by the largest sperm count - hardly surprising then that the testicles can weigh in at 500kg each. Gestation lasts between 11 and 12 months, producing a single calf which is then suckled for at least six months. The calf may consume a staggering 600 litres of milk per day in preparation for the journey south into colder waters. Calves can be as large as five meters and five tonnes at birth, and may grow as much as 2.5cm per day. A small percentage of southern right calves (invariably males) are born entirely white or mottled and will gradually turn grey with age.
Behaviour: Inhabiting all southern oceans, southern right whales feed selectively on copepods and krill during the summer months. They migrate north during winter to calve and mate in sheltered bays up as far as the tropics. As with the humpback whale, southern right whales appear only to feed opportunistically in the warmer temperate waters. Evidence now suggests that individuals return to South Africa each year and sightings reach a peak between August and October but are not unusual from June to November. At the peak in 2001 over 50 individuals were recorded simultaneously in Plettenberg Bay alone. Once reduced to a mere 10% of their original population, southern right whales were the foundation of the whaling industry in the 1800's. During this time and being the 'right' whales to kill, the stock declined rapidly as the catch comprised of mainly adult females, either pregnant or with calves - see history of whaling. The population of southern right whales is now increasing exponentially at the very encouraging rate of 7% per annum. At this continued rate we can expect the population to double within the next ten years.
BRYDES WHALEBRYDE'S WHALE - Balaenoptera edeni
 Identification: Bryde's whales can attain 14m and 20 tonnes. The body is sleek and dark-grey to mottled with a lighter underbelly. They have a prominent erect and hooked dorsal fin approx. three quarters down the body. When seen from the surface they can be difficult to distinguish from the minke and sei whales, however they have three distinct ridges along the top jaw which are not found in the other species.
Biology: Little is known. Gestation seems to be about a year and the resulting calf is then nurtured for another year before the female falls pregnant once again. Sexual maturity is reached at 12m for males and 13m for females after between 7 and 13 years.
Behaviour: There appear to be two populations off the Western and Eastern Cape - one remaining mostly offshore and migrating seasonally, while the other population is more or less resident in shallower waters. Bryde's whales feed on small crustaceans and shoaling fish, often scooping up huge mouthfuls by lunging up from depth. Being elusive animals, they tend to shy away from boats and seldom provide a good sighting unless feeding, although this year, a particular individual has shown more than just a passing curiosity in our boat. Sightings of Bryde's whales are most common from late Summer into Winter when they are often seen "'running" with common dolphins or when shoaling fish are closest to the shore - see the sardine run.
MINKE WHALE - Balaenoptera acutorastrata
 Identification: Minke whales are the most abundant and smallest of all baleen whales - attaining only 10m in length. The sleek, dark-grey upper body becomes lighter towards an almost white underbelly. The pectoral fins bear a distinctive white band and the dorsal fin is prominent and erect. When seen from above the head is distinctly pointed and resembles a V-shape.
Biology:Little is known. Gestation lasts about eleven months and the calf is nurtured for approx. five months. They reach sexual maturity at a length of around 7m.
Behaviour: Minke whales are mostly solitary animals. They can be found in temperate, coastal waters up to the tropics, although adults often spend the summer months in the feeding grounds of the Antarctic. They feed on small crustaceans and shoaling fish, tending to smash through shoals along the surface, unlike the brydes whales which often lunge up from below. Still hunted by certain countries, the "'acceptable" quota is adjusted annualy as minke whales are one of the least endangered of all whales. Sightings are rare in southern Africa.
BLUE WHALEBLUE WHALE -Balaenoptera musculus
 Identification: The blue whale, the largest organism on our planet is also the largest animal ever to have lived on our planet. Adults can reach almost 30m in length and weigh up to 100 tonnes. The body is slender, blue-grey and mottled in colour, with a small, sickle-shaped dorsal fin approx. three quarters towards the tail. When viewed from above, the head is broad and pointed with a ridge running from the tip to the blowhole. The distendable throat has over 40 grooves and the top jaw has over 300 baleen plates on each side to filter food.
Biology:Little is known. It seems that gestation lasts 11 months. The calves are approx. 7m at birth and can weigh between 2 and 3 tonnes. They are suckled for a period of about 7 months and can consume almost 400 litres of milk per day. Sexual maturity is reached at approx. 12 years of age and at a length of 22.5m for males and 24m for females.
Behaviour: Blue whales are found in all open oceans in small populations, though never common. They feed on krill, crustaceans and small schooling fish.
SPERM WHALE - Physeter catodon
 Identification: The sperm whale is a toothed whale and is the most widely recognised - it being the archetypal whale shape of myth and legend. Female spem whales tend to be smaller than the males which can attain 18m in length and weigh up to 45 tonnes. The body shape is unmistakable. The large square head is almost one third of the total body length. There is no distinct dorsal fin but, instead a series of 'bumps' are visible along the back and towards the tail. The pectoral fins are small, broad and rounded. The lower jaw is long and narrow with 18-25 large conical teeth that fit into sockets on the upper jaw. The single blow hole, located towards the front, left side of the forehead is s-shaped and produces a characteristic blow - forward and to the left. Colour can be blue-grey to light-brown to - legend has it - completely white in old age.
Biology: The gestation period of sperm whales lasts between 14 and 15 months. The resulting calves are approx. 4m at birth and are suckled for up to 3 years, with an interval between calves of 3-4 years. Sexual maturity is reached at around 10 years of age. Sperm whales were once highly prized for the large quantity and unique properties of the spermaceti oil found in the head - up to 2.5 tonnes in an adult male. This huge spermaceti organ dominates the vast head and focuses the click sounds and sonic pulses that the whale uses to echolocate and communicate. It is also thought that this organ may serve an important function as the animal dives and might even act as some form of buoyancy regulator at depth.
Behaviour: Found in all open oceans, sperm whales feed on giant squid, octopus and fish. They are completely adapted to deeper waters and are seldom found in coastal regions. The greatest freedivers of all, sperm whales have been recorded at depths of over 3000m, while remaining submerged for over two hours before surfacing.
Sperm whales are born into a matriarchal social unit. Most females will spend the rest of their lives within that unit, while the males will leave the group at about six years of age to form temporary bachelor groups, before becoming more solitary as they grow older.
Scientists have found that different groups of sperm whales consistently make different patterns of sounds. These click patterns, specific to particular 'clans' (consisting of thousands of animals) are thought to be passed on through social learning and as such provide further evidence of whale culture.
ORCA WHALEORCA or KILLER WHALE - Orcinus orca
 Identification: Unmistakable - you've all seen 'Free Willy'. The orca is the largest of all dolphins, attaining 9m and 8 tonnes. Orcas are most distinctive from the surface for having a huge dorsal fin - larger in males (up to 2m) than in females. The body is robust and glossy-black with distinctive, white markings. There are 10-12 large, conical teeth each side of each jaw.
Biology: Orcas breed the year round and calves are born after a 13-16 month period of gestation. They are then suckled for at least one year.
Behaviour: Found in tropical, temperate and polar waters, orcas tend to hunt in packs and often employ ingenious strategies. They feed on squid, fish, birds, seals, sharks, dolphins and even other whales. Unquestionably at the top of the marine food chain, they seem to have enough sense to disregard humans as a viable and sustainable resource. Only one human is known to have been killed by an orca - a trainer killed by a captive animal. The name "killer whale" derives more from their unsociable behaviour towards other species of dolphin and whale. Orcas are periodically sighted off the coast of southern Africa and distinct groups seem to return to specific locations where they target specific prey. Little is known about their migratory habits, although Navy records do indicate year-round activity in South African waters. See 2003 report for orca pictures.
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