Any form of body contact other tahn pounce, usually not forceful.
Reference
Slooten E. (1994) Behavior of Hector’ s Dolphin: classifying behavior by sequence analysis. Journal of Mammalogy, 75.4, 956-964.
One individual actively rubs a body part on another individual.
Reference
Connor R.C., Wells R.S., Mann J. & Read A.J. (2000) The bottlenose dolphin: Social relationships in a fission-fusion society. In: Cetacean Societies, Mann J., Conner R.C., Tyack P.L. & Whitehead H. (eds.) pp. 91-126. University of Chicago Press, Chicago.
Nibbling at another's body, usually at the flukes.
Reference
von Streit C. (1995) Behaviour of two bottlenose dolphin calves in their first year and mother-calf relationship. Working paper for the Behavioural Ethogram Workshop, 9th European Cetacean Society Annual Conference, Lugano, Switzerland, February 9-11 1995.
One dolphin swims parallel to another, belly to belly, with or without contact and simply mirroring the other dolphin's movement.
Reference
Miles J. A. & Herzing D. L. (2003) Underwater analysis of the behavioural development of free-ranging Atlantic spotted dolphin (Stenella frontalis) calves (birth to 4 years of age). Aquatic Mammals, 29.3, 363-377.
An animal invites a second animal to come up from below it and place the tip of its rostrum in its genital slit. The lower animal often turns partially on its side, sometimes supporting the horizontal flukes of the upper animal from its head to its outstreched pectoral flippers. In this position, the lower animal, its tail bent down slightly from the horizontal, propels the upper animal forward, only breaking from the pattern to rise for breaths of air. Sometimes it swims belly-up or dorsum-up during such propulsion.
Reference
Johnson C.M. & Norris, K. S. (1986) Delphinid Social Organization and Social Behavior. In Dolphin Cognition and Behavior: A Comparative Approach, R. J. Schusterman, J. A. Thomas and F. G. Wood (eds.), Lawrence Erlbaum Assoc., Hillsdale, NJ pp. 335-346.
One dolphin rests its pectoral fin against the flank of another dolphin, behind the other dolphin's pectoral fin and below or just posterior to the dorsal fin.
Reference
Connor R.C., Mann J. & Watson-Capps J. (2006) A sex-specific affiliative contact behavior in Indian Ocean bottlenose dolphins, Tursiops sp. Ethology, 112, 631-638.