The dwarf sperm whale is a toothed whale that belongs to the cetacean species which includes all species of whale, dolphin and porpoise.
As a whole there are around 80 – 90 recorded species of cetacea in existence today.
Measuring in at around 9 feet this whale is currently considered the smallest of the whale species and makes up one of three species within the sperm whale family.
The other two are the sperm whale (which happens to be the largest animal in the toothed whale family) and the pygmy sperm whale.
Like its other family members this whale has a spermaceti organ in its head, which is how this whale was given its name.
Due to their small size, slow behavior and solitary lifestyle these whales are very difficult to observe in the wild (let alone spot) so only a limited amount of information is currently known about them.
Physical Characteristics and Appearance
As stated previously when fully grown the dwarf sperm whale measures in at around 9 ft. long and weighs an average of 400 lbs. to 600 lbs.
Dwarf sperm whales are very similar in appearance to the pygmy sperm whale but have a slightly larger dorsal fin.
The center of its body is stocky but tapers down the closer you get the tail and flukes.
They have a bluish gray coloring with a lighter colored under body.
The dwarf sperm whale may have anywhere from 16 – 24 teeth on its lower jaw and up to 6 teeth on the upper jaw.
When threatened the dwarf sperm whale is able to produce a dark red ink which is believed to be used to blind and disorient its prey so that it can escape.
In some ways the ink it produces functions similar to the ink of an octopus that is trying to escape a predator.
As with other toothed whales the dwarf sperm whale has a single blowhole that it uses to breathe, however the length of time these marine mammals can dive for before resurfacing for air is unknown.
Diet and Hunting Methods
The dwarf sperm whale lives on a diet consisting primarily of small crab, shrimp, fish, octopus and squid.
Because these marine mammals are part of the toothed whale suborder they use echolocation to help them navigate the ocean, locate potential prey and avoid attacks from predators.
Habitat and Migration
Dwarf sperm whales prefer warmer tropical climates and are most commonly found in the waters of the continental shelf.
They are also believed to be more coastal than their other two family members of the sperm whale family (the sperm whale and pygmy sperm whale).
Although there are no official estimates on population size it is believed that there are at least 10,000 – 15,000 dwarf sperm whales inhibiting the ocean.
Social Structure and Communication
These whales are primarily solitary animals although they may occasionally be seen traveling in small pods of up to 10 members.
When it comes to social activities these marine mammals are fairly inactive and rarely if ever seen performing acrobatics behaviors such as breaching and tail slapping.
In most cases they are either swimming very slowly or logging (floating motionless) in the water.
While the reason for this behavior is unknown their inactive nature may help them stay undetected by predators looking to hunt them.
When they do communicate vocally there communication often consists of high pitched clicks and whistles which can be used for both echolocation and social interaction.
Mating, Reproduction and Lifespan
Unfortunately not much is understood about the breeding habits of the dwarf sperm whale.
The average gestation period for dwarf sperm whales is 9 – 11 months.
Baby whales measure between 3.3 – 4 feet at birth and typically weigh between 85 – 110 pounds.
After birth the baby whale is likely nursed by its mother and fed milk until it can hunt for food on its own.
once the dwarf sperm whale reaches sexual maturity between 2.5 – 5 years it is then able to mate and reproduce its own offspring.
In terms of lifespan it is currently believed that these whales only live until their mid 20’s.
Captivity
Little is known about the dwarf sperm whale.
They rarely ever approach humans or boats and prefer to keep their distance.
Attempts to hold them in captivity have failed due to the whales inability to survive in small man-made habitats such as aquariums.
These whales are however still being actively hunted and killed in certain parts of the world due to their coastal nature which makes them easier targets than other whale species.
In addition to being hunted these marine mammals have also been found accidentally entangled in fishing nets and may be endangered by polluted waters and/or food in and around the coast line.
Depending on how commercial their environment is there is a possibility of being struck by passing boats.
Natural Threats and Predators
Unfortunately no solid information exists regarding possible natural threats that the dwarf sperm whales may face, however it is possible that these marine mammals may be attacked by killer whale or sharks inhibiting their local environment as both of these animals are known to hunt and kill other whale species.
Attacks from killer whales however may be less common in certain areas as some killer whale populations (depending on where they live) may stick to a diet that consists almost exclusively of fish and other small prey.
Defenses
As stated earlier when the dwarf sperm whale is attacked it will release a dark ink from its body to blind potential predators.
As they escape their flukes help disperse the ink in the water to help increase the ink cloud and make it difficult for them to be seen.
Echolocation may also serve as an early warning system by helping these marine mammals detect nearby threats in advance before they can attack the dwarf sperm whale.
The dwarf sperm whales coastal nature may also help protect them from larger animals that live further out to sea.
Protected Species
As with other marine mammals dwarf sperm whales are a protected species and individuals caught hunting these marine mammals could face steep fines and even jail time.
Note: Due to difficulty observed these animals it is unsure how abundant or endangered their population may be.