Pygmy and Dwarf Whales in Hawaii
Scientific Name: Feresa attenuata
Pygmy killer whales, one of the most poorly-known species of dolphins in the world, are observed at least several times a year within Hawaiian waters. Through photo id’s, they (unlike pygmy killer whales anywhere else in the world) seem to be “regular” residents – never leaving the coastline. Our onboard studies have shown that Oahu has it’s own resident pod of pygmy killer whales.
Their stable, long-term relationships resemble the social behaviors of killer whales and pilot whales, with many forming bonds with other individuals for at least 15 years. There are probably 200 individuals in Hawaii’s waters.
Hawaii’s group is the only known case of a pygmy killer whale population that remains isolated in one area and doesn’t venture out to the open ocean. On average, they are spotted about 4-6 miles from Hawaii shores., on out to almost 10 miles. They aren’t found farther than that as there isn’t much food for them.
What the small pygmy killer whales lack in size, they make up for in attitude. These are formidable predators and are often known to attack other marine mammals, such as other dolphins escaping from the nets of tuna fisheries.
When a number of Pygmy Killers were brought into captivity in Hawaii and South Africa they were extremely aggressive, killing or attacking everything that was in or entered their pen — even killing one another. Hmm… let’s keep them wild, shall we?
Pygmy killer whales are easily recognized by their round bulbous heads and their white underbellies. At the water’s surface, their pods may be quite social and acrobatic, leaping, spy hopping, tail slapping, and occasionally bowriding. More frequently, they are resting- or ‘logging’ – where a group floats at the surface of the water, each animal still, rather like logs!
Robust body, Small size, Bulbous forehead, lacks a beak, White “lips”, chin, and belly; under slung jaw, Dark cape; Tall dorsal fin, sub-triangular, long based, lacks rigidity, often inclining to the side; White scratches and scars, The skull is asymmetrical and the right jaw is smaller and usually has one less tooth than the left jaw.
Impacts to Hawaii Pygmy Killer Whales
There are very few, probably less than 200 individuals, in this distinct pygmy killer whale population off the islands. The population’s limited number make it more vulnerable than other whale populations to potentially harmful human behavior.
There have been no reports of a pygmy killer whale dying as a result of Hawaii’s long-line tuna and swordfish fishery. But the mouth of a pygmy killer whale stranded on Oahu in 2006 had hook and line marks, indicating fishing lines affect the animals.
There has been no documented case of a pygmy killer whale being hurt by sonar. But there’s low probability anyone would be able to document such harm given the whales are so rare and because they generally spend their time miles offshore.
PYGMY SPERM WHALE
Scientific Name: Kogia breviceps
More information about the Dwarf and Pygmy Sperm Whales at NOAA’s Southwest Fisheries Science Center.
DWARF SPERM WHALE
Scientific Name: Kogia sima
(2005) Dr. Robin Baird reports that dwarf sperm whales are the sixth most commonly sighted odontocete around the main Hawaiian islands. This species’ small size, tendency to avoid vessels, and deep-diving habits, make finding them a true treasure.
Sighting Notes: Similar in appearance to the pygmy sperm whale, but has a larger dorsal fin, generally set nearer the middle of the back. Also, the dwarf sperm whale’s blowhole is positioned further forward.
The dwarf sperm whale has a shark-like profile (but with a more pointed snout than the pygmy sperm whale), gray and white countershading, and a light pigment block resembling a shark’s gill slit on the side of its head. Generally, a pair of short grooves similar to those in beaked whales is present on the dwarf sperm whale throat. It contains spermaceti in its melon.
Adults of this species are up to 2.7 m long and may weigh up to 272 kg. Length at birth is about 1 m.
Group sizes tend to be small, most often less than five individuals (although groups of up to 10 have been recorded). This species, like the pygmy sperm whale, is shy and undemonstrative when observed at sea. They often drift motionless at the surface. When startled, dwarf sperm whales may leave a large rust-colored cloud of fecal material behind as they dive. In at least one area, there appears to be a calving peak in summer.
Our wildlife tours focus on education and conservation with encounters conducted in the best interest of both humans and wildlife. We model admiration and deep respect for these wonderful mammals.