False Killer Whales in Hawaii
Scientific Name: Pseudorca crassidens
Hawaii’s insular population of false killer whales now have Endangered Species Status
False killer whales can be identified by their small conical beak-lacking heads. Males have more of an overhanging jaw then females do.
Their flippers have a distinctive hump or bulge in the middle of the front edge. False killer whales have dark coloration except for some lighter patches near the throat and middle chest. Their body shape is rather slender.
The dorsal fin, although variable in shape, tends to be falcate and slender, and is generally rounded at the tip (compare to a pointy pilot whale fin).
False killer whales share a very similar skull and other traits with true Orca (uncommon, long-lived, slow to mature, calve once every 6-7 years). However, they are quite distinct from them. For instance, though both are top predators, false killer’s rarely attack mammalian prey. And while Orca are quite popular, most folks have never heard of the pseudorca – false killer whale, or its plight.
In Hawaii, false killer whales feed primarily on mahi mahi, tuna, ono, mongchong and swordfish – as do the longline fisheries using 3/8-inch nylon rope thousands of feet long. Attached every three feet is a short line with a hook to which bait is attached. The longline is let out behind a boat and anchored to the bottom.
To increase success of finding prey, The false killer whales travel in a band that can be several miles wide. Likewise longliner fisheries can have miles of line and thousands of hooks set out, from just one boat.
There are two populations of Hawaiian False Killer Whales. The “insular” population, found nearer the islands and of which are the only known genetically isolated population. This popluation has been decimated over the past thirty years – the current population is estimated at only 123 individuals.The insular population also appears to be split into three subgroups. One of which is very discrete and rarely seen compared to the other two.
An outgoing, large dolphin that exhibits strong social bonds, false killer whales can belong to larger groups of up to 40 individuals. They have often been observed sharing food and supporting injured members of a pod.
These intriguing marine mammals have a breeding season that lasts several months. Females may not become reproductively mature until around 10 years of age. Males may not reach maturity until about 18! Life spans are estimated at 58 years for males and 62 years for females, who go through menopause.
False killer whales are bycatch of, or have interactions with a number of fisheries. They have been recorded interacting with Hawaii’s longline and bottomfish fisheries off the Northwestern Hawaiian Islands. These types of interactions often result in injury such as dorsal fin disfigurement or death. Dorsal fin disfigurement may affect reproduction and survival as dorsal fins help control body temperature.
Wild Side’s wildlife tours focus on education and conservation so that an interactive relationship can be maintained in the best interest of both humans and dolphins. We strive to foster admiration and deep respect for these wonder-full marine mammals.