Solitary dolphins

For reasons that are not fully understood, bottlenose dolphins are sometimes encountered which are living on their own. This seems very odd for what is normally a highly sociable species, and which more usually lives in a group. However, the same thing has been recorded for other species of social cetaceans including belugas and orcas, and solitary dolphins are actually quite common around the world.

There is a lot of anecdotal information about these dolphins (they often become quite famous) and scientists have also been studying them. Some of the relevant literature that has been written about them is listed below.

Solitary dolphins typically stay in a particular region for some time (perhaps weeks or months) and have certain localities within this range that they regularly frequent. This can include seemingly unlikely places such as marinas and busy shipping channels.

Not surprisingly, people will often flock in large numbers to see them and sometimes they will get into the water and attempt to swim or play with the dolphins. Over time, solitary dolphins become ‘habituated’ to people. They lose their natural reticence to interact and may start to actively seek interactions or human company. Researchers have shown that solitary dolphins typically progress through a series of stages and this has been summarised by Wilke et al. (2005) thus:

Stage 1

The dolphin appears and remains in a new home range, sometimes restricting itself to a small, protected part of the range often < 1km2. Dolphin may follow boats (usually fishing boats) or inspect fishing gear, but does not yet approach humans.

Stage 2

The dolphin becomes habituated to new range and may start to follow boats. Local people aware of its presence may attempt to swim with the animal. Dolphin appears curious but remains at a distance from swimmers. May bow ride or inspect ropes, chains and buoys, etc.

Stage 3

The dolphin becomes familiar with the presence of one or more people who have deliberately attempted to habituate it – this process may be assisted or even initiated by the dolphin. At this stage, the dolphin interacts with only a limited number of people in the water. Behaviour may include swimming in close proximity or diving side by side; the dolphin being touched including having its dorsal fin held to allow swimmers to be pulled along by the animal.

Stage 4

The presence of the animal becomes widely known, often assisted by media exposure. It becomes a local celebrity and tourist attraction, attracting visitors. During this stage, inappropriate human behaviour may provoke unwanted and possibly dangerous behaviour in the dolphin, including dominant, aggressive and sexual behaviours directed at humans. Unfortunately, the animals’ fascination with people (and visa versa) often gets the animals into trouble. The dolphins are large powerful marine predators and they may accidentally (or deliberately if they are frightened or frustrated) injure people in the water particularly by biting or butting but sometimes also just by trying to swim around them. There is also a risk of disease transmission.

Sometimes the dolphins become fascinated by boats and this may lead to them being struck by hulls and propellers.

Whilst the animals are in areas of high human activity the chances are that they will be harmed. There are exceptions to this and the bottlenose dolphin known as Fungi, who has been resident in Dingle Bay for many years, has come to little harm. He is, however, rather the exception to the rule and has a large range and is cared for by the local human community.

Generally, the more human interactions that occur with the animal, the bigger the problems tend to get, and the less likely the animal is to survive. So, our basic advice is to stay away from them if possible. If there is a good shore-based viewing site then it may be possible to watch the animals from the shore (which is unlikely to harm the animal or encourage further human interactions). If the animal is constrained in a small area – for example in a marina – it may be trapped. Even if there seems to be a way open to the sea the animal may perceive an obstacle and/or, for reasons that may not be clear to us, be too scared to exit. Such animals need to be treated very carefully to ensure that they are not further stressed.

There have been a number of incidents of solitary dolphins. We have collected a number of case studies to help us understand these incidents.

Literature about Solitary Dolphins

Lockyer, C. 1990. Review of incidents involving wild, sociable dolphins, worldwide. In: The bottlenose dolphin.

S. Leatherwood & R. Reeves (eds.). pp. 337 – 353. : Wilke, M., Bossley, M. & Doak, W. (2005). Managing human interactions with solitary dolphins. Aquatic Mammals, 31(4), 427 – 433.

Müller, M. 1998. La place des dauphins solitaires et familiers dans la Socio-ecologie des Grands Dauphins. PhD thesis, University of Paris

Dudzinski, K. M., Frohoff, T. G. & Crane, N. L. (1995). Behavior of a lone female bottlenose dolphin (Tursiops truncatus) with humans off the coast of Belize. Aquatic Mammals, 21 (2), 149 – 153.

Frohoff, T. G. (2000). Behavioral indicators of stress in odontocetes during interactions with humans: a preliminary review and discussion. Paper SC/52/ WW2 presented to the Scientific Committee of the International Whaling Commission (unpublished).

Simmonds, M. & Stansfield, L. (2007). Solitary-sociable dolphins in the UK. British Wildlife Volume 19 (2): December 2007: Pages 96 – 101.