Typical swimming speed is about 12 miles per hour. Short bursts are possible
up to 22 MPH. When dolphins repeatedly bow (or jump) as they swim rapidly forward, it is called "porpoising". In this beautiful
video (courtesy of Ron Graening and Adolf Wegmann) a large pod of dolphins is seen porpoising.
This is an odd term for a dolphin, as a porpoise is a different animal
than a dolphin. Porpoises are in the same class of animals called Cetaceans, but are a different species.
Perhaps the name porpoising was coined because porpoises often swim in this manner. Porpoising while swimming is an advantage
to a marine mammal such as the dolphin because it allows the animal to spend a portion of its swimming time out of the water
where there is less drag or resistance against its body. Thus, it allows the animal to achieve faster swimming speeds. It
may, indirectly, also provide more time for the animal to view its environment above the surface and may provide a fun
activity for the dolphin. This behavior, when associated with a ship's wake, is termed "bow riding", another form of porpoising.
Social Interactions
A major part of the dolphin's day is spent in social behaviors. Social interactions between dolphins
may include rubbing, touching pectoral fins, nursing, mating, and synchronous displays (performing behaviors together
such as bows). Athletic behaviors may include breaching (a form of a bow), porpoising and spy hopping (the dolphin's head
rising vertically out of the water to look around). Dolphins appear to prefer association with other particular dolphins
and also appear to recognize each other even after being separated for long periods of time.
Aggressive behaviors are used to establish dominance in the pod, a sign
of frustration or annoyance, or a response to aggression from others. Agression is used as a tool to manage relationships
with others (as most animals do). They may include tail slapping (kerplunking), jaw popping, pectoral slapping (as seen in
the video below), chasing, head-to-head racing, squawking at each other and raking. Males fighting with each other for
access to sexually available females is another example of aggressive behavior. Following such behavior, the aggressors will
often touch each other in a social way, almost as if they are "making up". Sometimes the aggressive behavior is more psychological
(e.g. taking an arched or "S" position) than physical (e.g. fin and tail slaps, open mouths, squawking). Most animals (including
dolphins) associate various body positions with what another animal is about to do. Aggression is one of those predictors
of behavior.
In the following video a 19 month old female dolphin calf is attempting to assert herself with her mother nearby.
The calf breaches (comes out of the water, landing on her side). Breaching is an aggresive behavior. The mother, a 10 year
old dolphin, immediately swims alongside the calf to re-establishes HER dominance by slapping her pectoral fin near the
calf. Young animals perform these behaviors as a preparation for adult life when they will attempt to be the dominant dolphin
in their adult pods.
Male toughness is often displayed by head-butting. Acts of aggression between dolphins can become so intense
that the animal to which the aggressive behavior is targeted will often go into exile, leaving its pod as a
result of losing a fight. Aggressive behavior often accompanies mating. The male will posture in front of the female with
his back arched. He will stroke, rub and nuzzle her. Mouthing and jaw popping are also forms of aggressive mating behaviors.
Infanticide, or the intentional killing of infants, has been observed with dolphins. There are reported cases
of male dolphins seen "calf tossing", or throwing calves into the air to kill them. It is believed that adult male
dolphins will kill a calf to cause the new mother to go into estrus and again be available for mating. Dominant female
dolphins have also been observed "stealing" newborn calves from sub-dominant new mothers.
The Ethogram
Ethology is the study of an animal's behavior as it relates to its environment. Dolphin social behavior is often
studied in captivity using a tool called an "ethogram". An ethogram is a catalog of specific behaviors employed by any species.
In producing an ethogram, an observer records behaviors of an animal which may be repeated and have significance. There is
a level of ambiguity in producing an ethogram, as it is highly dependent upon the observer’s skill in recording these
repeated behaviors. Behaviors are described without reference to their purpose, making the ethogram a record and not an interpretation
of behavioral effect.
Site Content
Understanddolphins.com contains information condensed from a number of reputable technical sources,
peer reviewed journal articles, and respected dolphin research facilities, as well as from my personal experiences and
observations as a dolphin VIP Tour Guide and Educator.
I have made every attempt to support the information presented in this site with video and still
photographic images. On a regular basis I plan to produce more of these images and will continue to update the site with these
as well as with any new and scientifically verified information which becomes available.
