Omura’s whale (aka the dwarf fin whale) is a small baleen whale that can be found living within tropical/subtropical environments in deep waters.
In addition to being small these whales are also rare and hard to find and researchers have been struggling to collect data on this marine mammal.
This article tries to bring light to some of the information that is known about Omura’s whale, however there is still a lot that is largely unknown about this species regarding where they live, how they socialize and how they breed.
Physical Appearance and Anatomical Characteristics
Measuring in at 32 – 38 ft. in length Omura’s whale is one of the smallest whales within the baleen whale species.
On average male whales tend to be 6 ft. shorter than their female counterparts.
While females can grow to lengths of 32 – 38 ft. the males tend to measure in at around 27 – 33 ft. long.
Some researchers believe that these marine mammals may be able to grow to lengths of up to 40 ft. long and weigh up to 22 tons, however not enough data has been collected to confirm their actual average and maximum size and weight.
In terms of appearance these whales are known for their close physical resemblance to the fin whale.
When viewed from a distance these marine mammals may be mistaken for a small fin whale, which is why they are sometimes referred to as the dwarf fin whale.
They have a dark gray skin tone on the upper body with the lower body appearing light gray or white.
Omura’s whale has an asymmetrically shaped jaw that is white on the right side and dark gray on the left.
There is also a large prominent ridge on the rostrum which may be followed by several smaller ones.
The whales dorsal fin is bow-shaped and rises sharply in a vertical manner.
Because this whale is a marine mammal there are a number of characteristics this whale shares with other mammals including being warm-blooded, giving birth and breathing air.
Diet and Hunting Methods
These whales are believed to survive on a diet consisting of euphasusiids and possibly fish.
Unfortunately, due to a lack of research data the exact diets of these marine mammals is unknown.
It is believed that like other species of baleen whale Omura’s whale uses a filter feeding method to capture its prey when hunting for food.
In several observations these marine mammals have been observed lunge feeding where they lunge at a group of prey and engulf as much food as possible.
Because these marine mammals are baleen whales they are born with baleen plates that have bristles attached to them which allow them to filter their prey from the water.
As these whales consume large amounts of food they use their bristles to separate their prey from the water that passes in and out of their mouth, hence the term filter feeding.
Habitat and Migration
Omura’s whale can be found living in tropical/sub tropical environments primarily in deep waters.
These whales have been spotted swimming through the waters of Western and Southern Australia, China, Malaysia, the Philippines and Thailand as well as a few other locations.
Since sightings of these whales is rare it is difficult to determine their primary habitat and whether or not they follow any particular migration patterns.
Social Structure and Communication
As with other data not much is known about their social structure or how they communicate.
Observations have shown that these whales are known to roll, breach the water and lunge feed.
They are also known to perform certain behaviors during mating periods such as rolling at the surface of the water to show that they are interested in mating with a partner.
Rolling
As the name suggest rolling involves a whale rolling over in the water either at or near the surface.
While the exact reason for this behavior is unknown it is assumed that it may play a role in showing interest during mating sessions or as a way to gain a better observation of their surroundings.
Breaching
Breaching occurs when a baleen whale lifts atleast 40% of its body above the water before landing back into the water and creating a huge splash.
Some whales perform breaches where up to 90% of their body rises above the waters surface before reentering the water.
Lunge Feeding
Lunge feeding is a technique used by baleen whales to capture prey.
This method of hunting involves swimming towards/through a group or school of prey and engulfing as much food as possible.
Vocalizations
Unfortunately nothing is known about their vocal communication.
What is typically known about the baleen whale suborder (which Omura’s whale belongs to) is that vocal communication often involves low pitched moans, grunts and whines.
Some whale species such as the common minke whale (also a baleen whale) have also been observed making pulse and boing sounds.
Due to the lack of captured vocal data no estimates can be given about the range, frequency, pitch or ones of these marine mammals.
Mating, Breeding and Reproduction
Insufficient data exists on the mating rituals, gestation period, nursing length, sexual maturity and lifespan of these marine mammals.
From observations of captured whales they are known to produce milk which is used to feed their young nutrients and healthy fat, however the length of lactation isn’t known.
Threats and Predators
Omura’s whale isn’t known to face many threats as compared to other whale species.
In the past these whales were occasionally hunted and killed by whalers interested in selling their meat and blubber, however whaling activities for these marine mammals appear to have been less extensive than other species because of their small size and the difficulties associated with locating and hunting these marine mammals.
Today Omura’s whale is rarely if ever hunted due to their rare appearances and the protected species act that is heavily enforced in numerous countries.
Aside from being (rarely) hunted for their meat these marine mammals may also face threats from accidental catches in fishing nets and other fishing gear, however this is also rare.
As with most marine mammals chemical pollution and noise pollution may play a role in endangering their habitat.
Natural threats for Omura’s whale are currently unknown.