Author: Morgan Cadle
What to Expect of the Bottlenose Dolphin in South Africa
In Southern Africa, the Bottlenose Dolphin is a major draw for wildlife enthusiasts. Specific spots where they can be spotted in South Africa include the coasts of Plettenberg Bay, Wilderness (in the Garden Route), Jeffreys Bay, Durban, and Sodwana Bay.
While standing on a boat, spectators can witness breathtaking displays such as breaching, tail slapping, spy hopping, where they peek above the water to survey their surroundings, and the fast and agile swimming that they are known for. In addition to these incredible sights, visitors can also spot these creatures engaging in mating and calving. These are common behaviours in the sheltered bays and warmer waters along the coast where conditions are ideal for raising young.
The Bottlenose Dolphin, also known as Tursiops truncatus, is one of the most beloved marine mammals around the world. This charismatic and intelligent creature is one of the many marine mammals that can be spotted off the coast of South Africa.
This species of dolphin got its common name from its distinctive and elongated snout that resembles a bottle. This very unique feature is easily recognizable and is one of the most characteristic traits of the species. Its scientific name, Tursiops truncatus, comes from the thought-to-be Latin word ‘Tursiops,’ which translates to ‘dolphin-like,’ and the actual Latin word ‘truncatus,’ which translates to ‘truncated,’ possibly referring to the dolphin’s rounded and stubby head.
The Bottlenose Dolphin has a typical lifespan of 40 to 50 years in the wild. There have been some cases of individuals that have lived in captivity longer than that due to the lack of predators, regular feeding, and veterinary care. The oldest recorded Bottlenose Dolphin was a female named Nellie. She lived at Marineland Dolphin Adventure in Florida, USA, and died in 2014 at the age of 61.
An adult Bottlenose Dolphin usually measures between 2 to 4 meters in length and weighs between 150 to 650 kilograms. They have a robust body, a very prominent dorsal fin, and a ‘bottlenose’. Their skin colour can vary from light to dark grey, with some lighter shades on the belly.
Distribution and Migration
Bottlenose Dolphins can be found in warm and temperate seas worldwide. They are commonly spotted along coastlines from the Pacific, Atlantic, the Mediterranean, and to various regions of the Southern Hemisphere. In Southern Africa, they are a common sight mostly along the coasts of South Africa and Namibia.
The time of year when they are most often seen varies from location to location, but for the people in Southern Africa, they are prevalent year-round, with peak sightings during the warmer months from November to March.
This species of dolphin is not generally known for long-distance, seasonal migrations like some other marine species; instead, they tend to exhibit a more localized and variable movement patterns. These movements are primarily driven by factors such as food availability, water temperature, and breeding requirements.
There have been some cases of Bottlenose Dolphins showing a degree of migratory behaviour. In more temperate areas, they may travel to warmer waters during colder months. That could occur because of environmental conditions and resource needs rather than the typical long-distance migrations observed in species like whales.
Breeding and Gestation
Breeding can occur at any time of the year, although in certain locations, there may be peaks that coincide with the warmer months. During the mating season, the male dolphins engage in various behaviours to attract females. The one common behaviour is the display of physical prowess and agility through acrobatic acts such as breaching (jumping out of the water), and high-speed swimming. Additionally, they may vocalize an intricate series of clicks, whistles, and burst-pulse sounds, which serves as a means of communication, telling nearby females about the male’s identity, location, and how ready they are to reproduce.
The males may also engage in social interactions with females, forming temporary alliances or partnerships. This allows them to stay close to a female which can establish social bonds, which are essential for their chances of successful mating.
The gestation period for a Bottlenose Dolphin is about 12 months, with the females giving birth to a single calf every 2 to 3 years. These newborn dolphins are relatively large compared to other cetaceans, typically measuring between 0.8 to 1.4 meters in length and weighing around 15 to 30 kilograms at birth.
Feeding Habits
The Bottlenose Dolphin is a predominantly carnivorous animal, feeding on a variety of fish and squid. They have a sophisticated hunting technique that involves high levels of cooperation and sometimes utilizing their sonar capabilities to locate prey. Additionally, they use a method called ‘herding,’ where a group of dolphins work together to corral schools of fish into tight formations. Once the fish are concentrated, the dolphins take turns darting into the school to feed.
Another hunting technique is called ‘fish whacking’ or ‘fish stunning,’ where they use their tails to slap the water’s surface, this creates shock waves that stun or disorient their prey, making it easier to capture individual fish from the chaotic school.
Common Habits
Bottlenose Dolphins are very social creatures, often seen in groups that can range from small pods to groups of over 100 individuals. They are highly intelligent, and their level of intelligence is showcased through their complex social structures and behaviours. Those behaviours have been known to include vocal communications and using echolocation for navigating and hunting.
Conservation Status
Today, the Bottlenose Dolphin is listed as ‘Least Concern’ by the International Union for Conservation of Nature (IUCN). Despite this, certain populations are currently under threat due to various factors, including habitat loss, pollution, and being caught in fishing nets.
