Marine biologists have made the first-ever field observations and captured footage of the world’s rarest and least-known species of whale — Omura’s whale — in their natural marine habitat.
The elusive species of whales have been filmed for the first time off the coast of Madagascar after they were first identified and described in 2003. Because there were no confirmed sightings of Omura’s whales for many years after the species was first identified in 2003, scientists had feared it was extinct.
Now, an international team of marine biologists with the Wildlife Conservation Society, led by Salvatore Cerchio, with the New England Aquarium (NEAQ) and Woods Hole Oceanographic Institution (WHOI), has confirmed in a study published in the Royal Society Open Space Journal on October 14 that they have observed a population of Omura’s whales in their natural habitat for the first time.
The groundbreaking study described in detail the “foraging and vocal behaviors, and habitat preferences” of the whales “in the shallow waters of coastal Madagascar.”
News of the sighting and filming of Omura’s whale, also known as dwarf fin whale (Balaenoptera omurai), is causing excitement among marine experts and enthusiasts. It comes after the corpse of a juvenile female individual, about 5.7 meters long, washed up on a beach in Western Australia after Tropical Cyclone Olwyn in March.
Being unfamiliar with the species, scientists were able to confirm that the dead specimen was an Omura’s whale only with the help of DNA profiling.
Scientists now believe that several sighting opportunities may have been missed because so little was known about the rare whales that were misidentified as Bryde’s whales. Omura’s whales are similar to Bryde’s whales, but Omura’s whales are slightly smaller, ranging in length from about 33 to 38 feet, and feature distinct markings that readily distinguish them from Bryde’s whales.
“Over the years, there have been a small handful of possible sightings of Omura’s whales, but nothing that was confirmed. They appear to occur in remote regions and are difficult to find at sea because they are small.”
Due to the fact that no confirmed reports of sightings of the marine mammals in the wild occurred for many years after the species was first identified, and the fact very little was known about the distribution and global population of the whales, marine biologists had feared that the species was extinct.
According to Cerchio, “What little we knew about these whales previously came primarily from eight specimens of Omura’s whales taken in Japanese scientific whaling off the Solomon and Keeling Islands and a couple strandings of dead animals in Japan.”
“This is the first definitive evidence and detailed descriptions of Omura’s whales in the wild and part of what makes this work particularly exciting,” he added.
The researchers were surprised to find Omura’s whales in the Indian Ocean off the northwest coast of Madagascar because data from previous studies had suggested the populations were native to the West Pacific off the coasts of Thailand, Indonesia, the Philippines and the Sea of Japan.
“The only problem was that Omura’s whales were not supposed to be in this part of the Indian Ocean. Rather, they should be in the West Pacific, near Thailand and the Philippines.”
The researchers observed 44 groups of Omura’s whales over a two-year period, photographed and cataloged 25 individuals and collected skin samples that were used to confirm the identity of the population in 2013.
The researchers were also able to characterize the species. Adult individuals, according to the study, range from 8 meters (26 feet) to 12 meters (40 feet), while calves vary from 3 meters (10 feet) to 5 meters (16.5 meters) in length.
“When we clearly saw that the right jaw was white, and the left jaw was black, we knew that we were on to something very special.”
The team plans to conduct further studies on the “vocalizations, behavior and population characteristics” of the species.
[Images via SciNews/YouTube]