Dolphins are social animals. They are usually seen in groups.
But what does that mean? Are they like a pack of wolves or a pride of lions, or are they like a herd of antelope?
The SDRP was the first chance for researchers to study the social behavior of the same wild dolphins over time. And four decades gives us a good perspective on what is now five generations of dolphins.
We’ve learned that dolphins have fluid social relationships [see Fission-Fusion Societies below].
Dolphins have fluid social relationships.
Groups of females [see Female Bands below] will often have similar home ranges, and include multiple generations of moms and their calves.
Males [see Males below] tend to for alliances with another male. They range more widely, looking for mating opportunities.
Juveniles [see Juveniles below] tend to associate together until they mature. Females tend to rejoin the female band of their mothers, while the males tend to pair off.
Bottlenose dolphins live in fission–fusion societies. That means that they swim in groups that are frequently splitting up and reforming with new members.
Groups typically contain 4-7 dolphins. Despite the frequently changing group membership, we’ve discovered patterns of associations among the females, males, and juveniles. Mothers and their calves are virtually inseparable for 3-6 years.
At the core of the Sarasota community are female bands. These bands include females that form nursery groups when they are accompanied by calves. The nursery groups tend to be built around females with calves of similar age.
Different bands favor different protected areas. Females frequent areas where they can readily find prey, which increases the survivability of their young. Often we see nursery groups near shallow grass meadows where prey fish are abundant.
Males often swim together in pairs once they reach sexual maturity. We call it an alliance.
These alliances usually last for the life of one of the dolphins. When one of the pair dies, the remaining dolphin often pairs up again. Male alliances have home ranges that are larger than those of females.
Males range widely, as they attempt to gain mating opportunities with receptive females.
A male alliance may disappear from the Sarasota area for weeks or months. They are sometimes seen in nearby dolphin communities.
For several years after they separate from their mothers, juvenile dolphins spend much time together in small groups.
They still mingle with adult dolphins on occasion, but they often are more seen together. Frequently we see active social behavior, including mating activities.
Dive deeper to learn more about juvenile dolphin behavior
Eventually, juvenile females mature and leave the the other juveniles. They then spend most of their time in their mother’s band.
There they will associate with their mother and younger and older siblings, as well as with other multi-generational family groups.
As they mature, juvenile male dolphins often begin to associate with another male dolphin, which becomes an enduring male alliance [See Males above].
Relevant SDRP Publications
Scott, M.D., R.S. Wells and A.B. Irvine. 1990. A long-term study of bottlenose dolphins on the west coast of Florida. Pp. 235-244 In: S. Leatherwood and R.R. Reeves (eds.), The Bottlenose Dolphin. Academic Press, San Diego. 653 pp.
Wells, R.S. 2003. Dolphin social complexity: Lessons from long-term study and life history. Pp. 32-56 In: F.B.M. de Waal and P.L. Tyack, eds., Animal Social Complexity: Intelligence, Culture, and Individualized Societies. Harvard University Press, Cambridge, MA.
All photos © Sarasota Dolphin Research Program under NMFS permit #522-1785