The Spinner dolphin gets it's name from it's incredible acrobatic
skills, as it leaps from the water in high spinning aerial movements,
though its scientific name originated in its reference to the
dolphin's long snout, or rostrum - longirostrus, meaning long
rostrum. All forms of Spinner dolphins measure between 1.3 metres
and 2.1 metres. Weight is generally around 45 kg to 75 kg.
This dolphin is often been seen resting and travelling with
numbers around 100 to 300, though groups of over 1,000 in offshore
regions are reported. Large groups then have smaller sub-groups
that define individuals according to age, sex and behavioural
activity.
Highly social, Spinners often associate with other cetaceans
such as Pilot Whales (Globicephala melas/macrorhynchus) and Spotted
Dolphins (Stenella frontalis/attenuata). Spinners are very acrobatic
with their somersaults, high spinning leaps and many other aerial
activities. They often jump from the water and continuously spin,
and their movements consist of a variety of leaps and spins, such
as the tail over head leap. They also enjoy bow riding on the
pressure of the bow waves. They are vocal in their whistles and
clicks, and can swim as fast as 20 km per hour. Spinners are particularly
active toward dusk. Below is a list and description of their various
aerial movements and behaviour.
These dolphins often leap in the company of fast-moving schools,
with the tail over head being the most common and vigorous. The
dolphin thrusts its entire body out of the water, throwing its
tail over its head and landing tail first on its dorsal cape or
back.
Dolphins travelling in moving schools are often seen rising
as much as l/2 of their bodies out of the water, then slapping
their back, side, or belly against the surface of the water. These
slaps often happen in the direction of travel, and do not create
the loud smacking sounds associated with tail slaps and spins
Bursting from the water, and by twisting its neck and body, Spinners
can perform as many as 7 rotations during a single leap that can
take them as high as 2 metres in the air in just over one second.
Spins are often performed in a series.
This behaviour may include stroking one another with their pectoral
fins, swimming belly to belly with another animal, or opening
one's mouth and raking the other animal gently with the teeth
(much like scratching). This is one way that they communicate
Dolphins are highly perceptive of their surrounding environment,
and are often found playing with inanimate objects in both captivity
and the wild. Dolphins have frequently been seen using plastic
bags, pieces of seaweed, or any other debris as objects to toss
around, drag off one's pectoral fins or flukes, and exchange with
other members, much like our "tag" or "catch."
games.
Most species of dolphins are attracted to the pressure wave
created by moving boats and is common behaviour as they ride on
the bow waves and stern waves. It is believed that this behaviour
is for pure enjoyment or a free ride, much like body surfing in
humans.
The Spinner dolphin feeds on a variety of fish and squid, often
swimming with the spotted dolphin though it's feeding area usually
goes much deeper. Spinners are different in the fact that they
are nocturnal in their feeding habits.
This dolphin breathes many times per minute. They have no fear
of boats and approaches them with ease, often accompanying them
for half an hour or more. A speedy swimmer, the Spinner dolphin
can travel at speeds of about 20 km per hour, with a top speed
of around 37 km per hour. It is believed that they can dive to
a depth of 6 metres to feed. There are a number of geographic
varieties of the Spinner dolphin, though there are no sub-species.