Short-Finned Pilot Whale
About the Species
Short-finned pilot whales are found globally in tropical and temperate oceans. They are one of two species of pilot whale, along with the long-finned pilot whale. The two species differ slightly in size, features, coloration, and pattern. In the field and at sea, it is very difficult to tell the difference between the two species.
Short-finned pilot whales are long-lived, slow to reproduce, and highly social. They live in stable groups of 15 to 30 animals composed of close family relatives, and tend to live in localized, resident populations, although some populations have wider ranges. Their diet consists primarily of squid, with a small amount of fish. They are commonly found along the coast close to the continental shelf, although some populations have been found to extend into deep, open ocean environments such as in the eastern tropical Pacific Ocean. Pilot whales are often involved in mass strandings for reasons that are still unclear.
Three stocks of short-finned pilot whales are recognized in U.S. waters, which live along the U.S. east and west coasts, and around the Hawaiian Islands. On the west coast, short-finned pilot whales were once commonly seen, with an apparently resident population around Santa Catalina Island. After a strong El Niño in 1982 and 1983, short-finned pilot whales virtually disappeared from this area, and there are now thought to be about 800 animals in the West Coast stock. About 23,500 animals comprise the East Coast stock, around 2,000 in the Gulf of Mexico stock, and about 9,000 animals in the Hawaiian stock.
Short-finned pilot whales, like all marine mammals, are protected under the Marine Mammal Protection Act.
The short-finned pilot whale has a bulbous melon head with no obvious rostrum. Its dorsal fin is far forward on its body and has a relatively long base. The body is black or dark brown, with a large gray saddle behind the dorsal fin.
Behavior and Diet
Short-finned pilot whales feed mainly on squid, but they may also feed on octopus and fish, all from moderately deep water of 1,000 feet or more. When they are traveling and foraging, a pilot whale group can spread out over an area a half-mile wide.
Short-finned pilot whales often occur in groups of 25 to 50 animals. Males have more than one mate—typically a group has one mature male for every eight mature females. Males generally leave their birth school, while females may stay in theirs for their entire lives.
They are known as the “cheetahs of the deep sea” for their deep, high-speed dives to chase and capture large squid.
Where They Live
Short-finned pilot whales prefer warmer tropical and temperate waters. They can be found at varying distances from shore but typically prefer deeper waters. Areas with a high density of squid are their main foraging habitats.
Lifespan & Reproduction
Short-finned pilot whales mature at around 10 years of age. The maximum lifespan is 45 years for males and 60 years for females.
Females have calves every 5 to 8 years. Older females do not give birth as often as younger females. They are pregnant for about 15 months, then nurse for at least 2 years. The last calf born to a mother may be nursed for as long as 15 years.
Entanglement in Fishing Gear
Short-finned pilot whales can become entangled in fishing gear, either swimming off with the gear attached or becoming anchored. They can become entangled in many different gear types, including gillnets, longlines, and trawls. Once entangled or hooked, whales may drag and swim with attached gear for long distances, resulting in fatigue, compromised feeding ability, or severe injury, which may lead to reduced reproductive success and death.
Short-finned pilot whales are directly targeted and hunted in Japan and the Lesser Antilles.
Vessel strikes can injure or kill short-finned pilot whales. Scarred short-finned pilot whales have been observed in Hawaiian waters.
In the Spotlight
This species is protected under the Marine Mammal Protection Act of 1972 as amended.
Reducing Bycatch in Fishing Gear
Bycatch in fishing gear is a leading cause of short-finned pilot whale deaths and injuries in U.S. waters.
To reduce serious injuries and deaths of several marine mammal stocks incidental to the California thresher shark/swordfish drift gillnet fishery, NOAA Fisheries implemented the Pacific Offshore Cetacean Take Reduction Plan. Representatives from the fishing industry, regional fishery management councils, state and federal resource management agencies, the scientific community, and conservation organizations worked together to recommend mitigation measures to reduce entanglements. The plan includes gear modifications, such as net extenders and pingers, as well as skipper education workshops.
To reduce deaths and serious injuries of long-finned pilot whales incidental to the Atlantic pelagic longline fishery, NOAA Fisheries implemented the Atlantic Pelagic Longline Take Reduction Plan. Representatives from the fishing industry, regional fishery management councils, state and federal resource management agencies, the scientific community, and conservation organizations worked together to recommend mitigation measures to reduce bycatch of short-finned pilot whales. The plan includes a special research area, gear modifications, outreach material, observer coverage, and captains’ communications.
Reducing Vessel Strikes
Collisions between whales and vessels can injure or kill whales and damage vessels, but they often go unnoticed and unreported. The most effective way to reduce collision risk is to keep whales and vessels apart. If this is not possible, second best is for vessels to slow down and keep a lookout.
Addressing Ocean Noise
Underwater noise threatens whale populations, interrupting their normal behavior and driving them away from areas important to their survival. Increasing evidence suggests that exposure to intense underwater sound in some settings may cause some whales to strand and ultimately die. NOAA Fisheries is investigating all aspects of acoustic communication and hearing in marine animals, as well as the effects of sound on whale behavior and hearing. In 2016, we issued marine mammal acoustic technical guidance for assessing the effects of anthropogenic (human-caused) sound on marine mammal hearing.
Overseeing Marine Mammal Health and Stranding Response
We work with volunteer networks in all coastal states to respond to marine mammal strandings including all whales. When stranded animals are found alive, NOAA Fisheries and our partners assess the animal’s health and determine the best course of action. When stranded animals are found dead, our scientists work to understand and investigate the cause of death. Although the cause often remains unknown, scientists can sometimes attribute strandings to disease, harmful algal blooms, vessel strikes, fishing gear entanglements, pollution exposure, and underwater noise. Some strandings can serve as indicators of ocean health, giving insight into larger environmental issues that may also have implications for human health and welfare.
Marine Mammal Unusual Mortality Events
Short-finned pilot whales have been part of a declared unusual mortality event in the past. Under the Marine Mammal Protection Act, an unusual mortality event is defined as "a stranding that is unexpected; involves a significant die-off of any marine mammal population; and demands immediate response." To understand the health of marine mammal populations, scientists study unusual mortality events.
Educating the Public
NOAA Fisheries aims to increase public awareness and support for pilot whale conservation through education, outreach, and public participation. We regularly share information with the public about the status of pilot whales, as well as our research and efforts to promote their recovery.
In 1997, NOAA Fisheries implemented the Pacific Offshore Cetacean Take Reduction Plan, which requires the use of pingers and 6-fathom net extenders in the California/Oregon drift gillnet fishery to reduce bycatch of cetaceans, including short-finned pilot whales. The Pacific Offshore Cetacean Take Reduction Team continues to meet and recommend measures to further reduce bycatch and achieve MMPA goals.
In 2009, NOAA Fisheries implemented the Pelagic Longline Take Reduction Plan, which includes a mainline length requirement as well as research and observer coverage recommendations. The Atlantic Pelagic Longline Take Reduction Team continues to meet and develop recommendations for further reducing bycatch of pilot whales and achieving MMPA goals.
Key Actions and Documents
NOAA Fisheries conducts various research activities on the biology, behavior, and ecology of the pilot whale. The results of this research are used to learn more about this species.
Determining the number of pilot whales in each population—and whether a stock is increasing or decreasing over time—helps resource managers assess the success of enacted conservation measures. Our scientists collect information and present these data in annual stock assessment reports.
Acoustic research at NOAA uses underwater microphones to record sounds made by whales and dolphins. Once the recorders are collected and brought back to the lab, those sounds are detected on the recordings, and classified to species when possible. Using this data, scientists are able to learn more about the distribution and abundance of a species than using visual observations alone.
NOAA scientists have used recordings of short-finned pilot whales to describe their acoustic behavior and improve our descriptions of their stock structure in the Pacific Ocean. Similar experiments track the response of short-finned pilot whales to human-generated sounds by playing recordings of those sounds and observing the response of animals in the wild.
Eventually, what we learn about the way different species vocalize can be used to detect and count cetaceans using autonomous gliders and passive acoustic arrays.
Molecular Genetic Research
Molecular genetic techniques are invaluable tool in cetacean research. Cetaceans are elusive, spending little time at the surface, and often live in remote areas that are difficult to sample. Because of this, classifying species and population structure using traditional morphological methods often gives us an incomplete picture of cetacean diversity. Analyses of molecular genetic markers provide insight about species’ population structure and diversity, and can reveal cryptic populations or subspecies that may be separated by oceanographic features, ecological differences, or social structure.
NOAA Fisheries has been using mitochondrial DNA control region sequences to examine population structure of short-finned pilot whales in the Pacific Ocean. Using these sequences, we have described the distribution of two types of short-finned pilot whale in the Pacific Ocean – one in the eastern Pacific Ocean, and the other in Hawai‘i and the western Pacific Ocean. In Hawai‘i, we’ve identified a resident population around the main Hawaiian Islands that is likely reproductively isolated from individuals in the Northwestern Hawaiian Islands and open ocean surrounding the islands.