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    BOTTLENOSE DOLPHINBOTTLENOSE DOLPHIN - Tursiops aduncus & Tursiops truncatus
 Identification: The beak (rostrum) of the bottlenose dolphin, narrows abruptly from the head. The dark upper body fades to an off-white underbelly, however individuals become speckled with age. The dorsal fin is prominent and hooked. Tursiops aduncus is the most frequently observed inshore species, attaining a length of 2.4m. Tursiops truncatus is much larger (over 3m and double the mass) and is not often encountered inshore. Truncatus has a more noticably blunt and abruptly sloping forehead with a shorter beak.
Biology: Calves are born throughout the year, although births reach a peak during the spring and summer months. A single calf is born after a years gestation. Suckling continues for up to four years and females become sexually mature at approx. ten years - three years sooner than the average male. Both sexes may live for over 40 years although females tend to live longer than males.
Behaviour: Observations of Tursiops aduncus in the Western Cape have identified four distinct group types: Nursery groups consisting of related females and calves - dolphin society is matriarchal: Young adult groups of both sexes - are usually larger and more playful groups: Small groups of 2-4 males - sometimes accompanied by a female: Mixed groups - which may consist of some or all of the above group types. Hunting collectively and feeding on bony fish and squid, group size is often an indication of how much food is available in a particular area. The national average group size is 60 animals, whilst the Garden Route average is double that at 120 animals. The KwaZulu Natal average is only 20 animals, although this may be directly attributed to the dolphin by-catch of the regions shark nets.
The inshore bottlenose dolphins - Tursiops aduncus - can be found year round along the entire coastline east of Cape Town. Of all the dolphin species they are the most inclined to interact with humans. Masters of the surf zone they are always a pleasure to watch. They seem not to be disturbed by boats and often bow ride, back-splash and sommersault in their presence. Regarding surfers and divers with only a passing curiosity, they do occasionally take time out to teach us some new tricks.
INDO-PACIFIC HUMPBACKED DOLPHIN - Sousa chinensis
 Identification: Humpbacked dolphins attain up to 2.7m in length and have a long, relatively narrow beak (rostrum). The body is robust, dark grey to brown on top and paling underneath. The most distinctive feature is the long shallow hump located beneath a small and hooked dorsal fin. Moving east however, both colouration and form do vary considerably, with the dorsal fin becoming larger on a less obvious hump and the colouration becoming brown and speckled to almost completely white - as found in the pink dolphins of Hong Kong. There is currently much debate as to whether these are now in-fact, two separate species - the Indian humpbacked dolphin (Sousa plumbea) and the Pacific humpbacked dolphin (Sousa chinensis).
Biology:Calves are born throughout the year, but most arrive during the spring and summer months after a 12 month gestation period. Suckling may continue for several years. Females are sexually mature after approx. ten years - three years sooner than the average male and both sexes may live for over 40 years.
Behaviour: Found in temperate to tropical waters the population in Southern Africa is small and estimated at only 1200 animals. Groups of between 3 and 20 humpback dolphins can be found in isolated groups along the entire coastline between Cape Town and Mozambique. Shying away from boats and humans, they hunt close to the shore and feed on reef and estuarine fish. Unfortunately their inshore reliant habits expose them to a higher level of pollution and toxins - run-off from farms and industries inland. Feeding in esturaries and river mouths, they absorb and accumulate these toxins which are then passed on, through the milk to the first-born calf, which is invariably too small to tolerate such levels - a 10 year build up before the female is sexually mature. Subsequent calves will usually survive as the accumulation period of toxins is much shorter - approx. 2 years between calves. Shark nets are also a significant facor in reducing the numbers of such an inshore reliant species.
Current research is trying to establish group movements and at this stage they are thought to be very localised animals. Sightings are year round and the Garden Route affords some of the best opportunities with 120 individuals identified in the area - 10% of the estimated population in southern Africa. Although humpbacked dolphins are notoriously shy of boats and humans they have been known to get used to certain vessels - as seen by those undertaking research - and will occasionally approach and investigate boats. On the rare occasions when they are seen to surf and leap they are unquestionably the most spectacular of acrobats.
COMMON DOLPHINLONG-BEAKED COMMON DOLPHIN - Delphinus capensis
 Identification: Common dolphins attain 2.5m, and are less robust in appearance than bottlenose dolphins. The body is dark-brown to black with characteristic, orange-brown, 'figure of eight' markings on the sides and a creamy-white underbelly. The head slopes gently forward to a long narrow beak and the dorsal fin is prominent, slightly hooked and triangular. A dark stripe extends up from the pectoral fins to the lower jaw and another joins the back of the beak to around the eye. Click here for pictures of common dolphins
Biology:As with most dolphins, calves are born throughout the year but births peak in summer after approx. one year gestation. They are then suckled for only six months. Females are sexually mature at approx. nine years - two years sooner than the average male. Both sexes may live for over forty years.
Behaviour: Common dolphins are found offshore in most temperate to tropical waters. To be lucky enough to 'run' with common dolphins must be considered amongst the highlights of a lifetime. Common dolphins are usually found in large groups (500 - 3000, although over 9000 were sighted off Plettenbergbay in 1999). They are very gregarious and positively 'love' boats. Moving at high speeds whilst chasing prey, they will utilise the bow wave and the wake of a boat in order to save energy. At top speeds (we've clocked them at almost 20 knots) they will also 'porpoise' and leave the water entirely. Watching common dolphins move through water is to witness apparently effortless motion and the peak of aquatic evolution. Common dolphins are usually only found in the deeper coastal waters, however they are occasionally seen from shore during the summer months in the Western Cape, kwaZulu natal and Mozambique when they follow migrations of schoaling fish up the coast. - see sardine run.
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