The spinner dolphin (aka the long-snouted dolphin) is well-known for its acrobatic stunts and its ability to spin as it leaps out of the water, which is where the name spinner comes from.
This dolphin has four subspecies of spinner dolphins known as the central american spinner dolphin, eastern spinner dolphin, Hawaiian spinner dolphin and dwarf spinner dolphin.
All species are part of the cetacean family and belong to the toothed whale suborder.
Physical Characteristics and Appearance
These dolphins have a streamlined body with a protruding but narrow snout and a triangular-shaped dorsal fin.
In terms of size the spinner dolphin is one of the smallest species of dolphin measuring in at around 4 1/2 – 8 feet in length and weighing between 50 – 175 pounds when fully matured.
Most dolphins have a skin tone that fades from dark to light gray starting around the dorsal fin area which is a dark gray that fades to a light gray around the sides of their body and to a lighter gray or white under-body or belly.
Diet and Hunting Methods
The typical diet for the spinner dolphin includes a variety of fish, shrimp and squid.
Hunting may occur in groups where one group of dolphins will swim around their prey herding them into a small dense ball while one or two other dolphins swim through the densely compacted group of fish and take turns consuming the scared and paralyzed fish.
While these dolphins may eat at any time of the day they tend to prefer hunting at night when their prey moves towards the surface of the water, which makes it easier for the dolphins to find abundant supplies of food and minimize their diving efforts.
During deep dives the spinner dolphin may dive to depth of nearly 1,000 ft and it is estimated that this species of dolphin can hold its breath for up to 5 – 10 minutes.
Social Structure and Communication
Spinner dolphins are known to form loose bonds with one another and may be seen interacting with different groups at different times.
They are also non monogamous creatures and may be found changing mating partners every couple of weeks or so.
Mother dolphins often form close bonds with their calves and may continue to feed and nurture their young for up to 2 years.
These dolphins communicate using a combination of clicks and whistles, and each dolphin has a unique frequency that allows them to determine which one is speaking when in a large group.
In some cases a dozen or so males may choose to bond together and form a temporary pod where they’ll forage and hang out with one another.
Mating, Reproduction and Lifespan
The average gestation period for the spinner dolphin is estimated to be around 10 – 11 months.
Spinner dolphins are a non monogamous species and female dolphins may end up mating with multiple males over the course of several months.
Female dolphins may bear a single offspring once every 2 – 4 years and are known to develop close bonds with their children.
In some cases the mother may continue to nurture her child for up to 2 years.
Female dolphins sexually mature at around 4 – 7 years of age, while males mature between 6 – 10 years of age and these dolphins have an estimated lifespan of 20 – 30 years.
Habitat and Migration
The spinner dolphin can be found living in most tropical and sub tropical climates and prefers to live in or around the coastal regions, however in some locations they may also be found swimming far from the coastline.
These dolphins enjoy living in warm waters that are several thousand feet deep because this is where the majority of their food can be found.
During deep dives the spinner dolphin may dive to depths of nearly 1,000 feet.
They can also be found aggregating in groups of several hundred or thousand dolphins in certain tropical areas.
Some of the popular areas spinner dolphins are known to live in include the tropical Eastern Pacific, Hawaii and Central America .
Threats and Predators
In the past spinner dolphins were hunted for their meat which was sold as a form of tuna.
Today however this is much less common, although some poachers still hunt them for their meat.
The spinner dolphin also faces threats from various parasites, sharks, killer whale and pilot whales, as well as threats from man-made materials and machinery such as boats and fishing nets.