False Killer Whales


False Killer Whale Main Hawaiian Island insular population listed as an Endangered Species

On November 12, 2012, the National Marine Fisheries Service officially announced that the Hawaiian inuslar population of false killer whales was to be listed as an Endangered Species.


False Killer Whale

Hawaii is home to a genetically unique population of false killer whales, known to scientists as Hawaiian insular false killer whales (the word "insular" means "of or pertaining to an island"). It is estimated that fewer than 123 are alive today and only 46 are females capable of breeding. This population is very close to extinction.

False killer whales are marine mammals that have a life span similar to that of humans. They form long-lasting relationships and are known to engage in a fascinating sharing ritual of passing a caught fish between the members of their group before consuming it.

Pacific Whale Foundation's research department studies the distribution of false killer whales in order to better understand any overlap with areas of high concentration of marine debris as well as overlap with commercial longline fishing areas. Policy makers can use this information to make well-informed decisions regarding the recovery of this population. 


  • False killer whales (Pseudorca crassidens) are actually not whales; they are the fourth largest member of the oceanic dolphin family. These animals can grow to weigh approximately 1,500 pounds.
  • False killer whales are gregarious and form strong social bonds. They are usually found in groups of 10 to 20 that belong to much larger groups of up to 40 individuals in Hawaii and 100 individuals elsewhere.
  • False killer whales are found in tropical to temperate waters around the world. Three populations of false killer whales have been identified in Hawaii: Main Hawaiian Islands (Hawaiian insular), Northwestern Hawaiian Islands, and offshore (pelagic) stocks.
  • Hawaiian insular false killer whales are a distinct population that lives its entire life around the Hawaiian islands, in an area ranging up to 70 miles. They have marked genetic differences from other false killer whales, as well as different behaviors and “cultural” patterns, including how and where they locate prey. 
  • When you consider that a mature female false killer whale gives birth only once every 2 to 4 years on average, their current numbers are almost too small to sustain a population. 


  • Make a symbolic adoption of a false killer whale to fund further research.


  • False killer whales feed on tuna, mahi mahi, wahoo (ono), and other large, deep-water fish. These fish are also targeted by Hawaii’s longline fisheries.
  • Longlining features a long horizontal line that can stretch up to 50 miles. Shorter lines dangle from the “long line” at spaced intervals. These shorter lines hold bait hook to attract fish.
  • False killer whales have learned to steal bait and bite off hooked fish from longlines, but these “easy” meals come with risk: false killer whales get hooked or entangled in the lines and can die or become injured.
  • Between 1997 and 2009 in Hawaii, 43 false killer whales were hooked or entangled with longline fishing gear, and three died as a result. False killer whale bycatch in Hawaii has exceeded “sustainable levels” since at least 1999, meaning that these animals are being killed at a rate higher than what the population can sustain. 
  • Longline fishers can take steps such as using circular hooks or weaker hooks, to protect false killer whales and other marine mammals.
  • With the depletion of many fish species due to overfishing, false killer whales are struggling to find food in general. There are fewer fish to hunt, and the ones that are found are smaller than in the past. The fish they consume contain organochlorines (PCBs and PBDEs) and other contaminants that threaten these animals and people alike. Because false killer whales are top level predators, their bodies accumulate PCBs and other toxins, putting them at a greater risk of infection and disease. They need every protection we can provide them; and they need it right now.


  • Due to its extremely small population size and limited range, the Natural Resource Defense Council (NRDC) petitioned in 2009 to list the Hawaiian insular population of false killer whales as "Endangered" under the Endangered Species Act. 
  • In August 2010, the National Marine Fisheries Service (NMFS) released a final “Status Review” concluding that the population was both a distinct population segment and at a “high risk of extinction”. 
  • In November 2010, NMFS officially proposed to list the Hawaiian insular falsle killer whale population as "Endangered" and under federal regulations had until November 2011 (one year) to make a final ruling on the proposal. 
  • Pacific Whale Foundation testified on its behalf at a NMFS hearing in Honolulu and also submitted written testimony and petition signatures from our members and supporters.
  • In March 2012, NRDC sued NMFS for their failure to meet the November 2011 deadline to make a final ruling. 
  • On November 21, 2012, NMFS released a "Final Rule" announcing that the Hawaiian insular population of false killer whales was to be listed as an Endangered Species/


NOAA Fisheries, Office of Protected Resources, False Killer Whale http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/falsekillerwhale.htm

NOAA Fisheries, Office of Protected Resources, False Killer Whale Take Reduction Team (includes a link to the Draft Take Reduction Plan to Reduce Bycatch of False Killer Whales in Hawaii-based Longline Fisheries) http://www.nmfs.noaa.gov/pr/interactions/trt/falsekillerwhale.htm