Pilot whales eat squid. That is the short, honest answer for both the long-finned and the short-finned species. Stomach-content studies consistently show that cephalopods, particularly open-ocean squid, make up the vast majority of what pilot whales consume, though fish turn up in the mix depending on where the whales live and what season it is. The hunting side of the equation is just as interesting: pilot whales are deep-diving predators that chase prey hundreds of meters below the surface, sometimes sprinting at speeds that have earned them the nickname “cheetahs of the deep sea.”
Squid Dominate the Menu
When researchers examine what pilot whales have actually been eating, squid beaks are the most common item they find. Because squid beaks are made of chitin, they resist digestion far longer than soft tissue and accumulate in the stomach, giving scientists a reliable record. A study of long-finned pilot whales mass-stranded in Tasmania recovered over 960 identifiable lower beaks from 26 species of cephalopod. The family Ommastrephidae, a group of muscular open-ocean squid sometimes called “flying squid,” was the single most important prey by reconstructed mass, accounting for roughly 46% of the total.1PLoS ONE. Stomach contents of long-finned pilot whales, Globicephala melas mass-stranded in Tasmania
Short-finned pilot whales show a similar reliance on squid but target somewhat different species. Stomach contents from short-finned pilot whales stranded in North Carolina revealed that Brachioteuthis riisei, a small oceanic squid, was the most abundant prey item by number, making up about 28% of identified cephalopods. Two other deep-water squid families, Cranchiidae and Histioteuthidae, also featured prominently.2Marine Mammal Science. Stomach contents of mass‐stranded short‐finned pilot whales (Globicephala macrorhynchus) from North Carolina In the Canary Islands, stomach contents from a young short-finned pilot whale contained 15 species of squid, mostly from families that migrate vertically through the water column each day.3PubMed Central. Early prey intake of a short-finned pilot whale (Globicephala macrorhynchus Gray, 1846, Cetacea: Delphinidae) in the Canary Islands
Fish are not absent from the diet, but they play a supporting role. In the North Carolina strandings, a large number of otoliths (the tiny ear bones of fish, which also resist digestion) from a deep-sea species called Scopelogadus beanii turned up alongside the squid beaks, representing about a quarter of prey items by number.2Marine Mammal Science. Stomach contents of mass‐stranded short‐finned pilot whales (Globicephala macrorhynchus) from North Carolina A broad survey of deep-diving toothed whales in the Bay of Biscay found that fish was an important food source only for the Sowerby’s beaked whale and, to a lesser extent, the long-finned pilot whale. Most of the other deep divers in that community were eating almost exclusively squid.4Deep Sea Research Part I: Oceanographic Research Papers. Prey preferences among the community of deep-diving odontocetes from the Bay of Biscay, Northeast Atlantic
How Diet Shifts by Region and Season
Pilot whales are found across a wide swath of the world’s oceans, and what they eat varies with geography. In the northeast Atlantic, long-finned pilot whales near Iberia consumed more octopus (specifically Eledone cirrhosa) than those sampled near Scotland. Octopus was also more common in the diet during the first half of the year and in larger whales.5Marine Mammal Science. Patterns and trends in the diet of long‐finned pilot whales (Globicephala melas) in the northeast Atlantic The same study found evidence of seasonal shifts in the overall diet composition, not just the octopus component.
Stable isotope analysis of long-finned pilot whales in the Strait of Gibraltar backs this up. Nitrogen isotope ratios differed significantly between summer and winter, suggesting the whales were feeding at different positions in the food web across seasons, likely switching between prey species as availability changed.6Marine Biology. Diet of the social groups of long-finned pilot whales (Globicephala melas) in the Strait of Gibraltar
Short-finned pilot whales show a parallel pattern. Fatty acid profiles from blubber samples of short-finned pilot whales in the Canary Islands and Madeira archipelagos revealed distinct trophic niches between the two populations. The Canary Islands whales appear to forage closer to the seafloor, while those around Madeira lean toward a more open-ocean diet, likely taking advantage of the nightly upward migration of deep-water prey layers.7PubMed. Intraspecific variation in the feeding habits of short-finned pilot whales based on blubber fatty acid profiles Some whales showed fatty acid profiles that overlapped with both groups, suggesting they travel and forage across a broader area that encompasses both archipelagos.
The long-finned pilot whale in the Bay of Biscay stands out for its dietary flexibility. It was the only toothed whale in the local deep-diving community found to forage in both open-ocean (pelagic) and near-bottom (demersal) habitats.4Deep Sea Research Part I: Oceanographic Research Papers. Prey preferences among the community of deep-diving odontocetes from the Bay of Biscay, Northeast Atlantic That adaptability may help explain why pilot whales are among the most widespread and numerous of the larger toothed whales.
Deep Diving to Reach Prey
Squid do not make themselves easy to catch. Many of the species pilot whales target live at mesopelagic depths, roughly 200 to 1,000 meters below the surface, during the day. Pilot whales routinely dive into this zone, and tagging studies have revealed a surprisingly complex diving repertoire. Short-finned pilot whales off the Canary Islands performed dives that researchers sorted into four behavioral states. The shallowest dives had a median depth of about 27 meters and lasted around three minutes with almost no foraging buzzes. The deepest dives were long, reaching well below 500 meters, and had very high rates of echolocation buzzes, the acoustic signature of active prey capture attempts.8Scientific Reports. Hidden Markov models reveal complexity in the diving behaviour of short-finned pilot whales Between these extremes sat two intermediate dive types that varied in depth, duration, and buzz rate.
This layered approach makes sense when you consider the trade-offs. Shallow dives are cheap in terms of oxygen and energy but offer access only to whatever prey happens to be near the surface. Deep dives are metabolically expensive but put the whale within striking distance of the large, calorie-rich squid that form the core of its diet. Pilot whales appear to adjust their dive strategy depending on what is available, mixing shallow and deep dives across a foraging bout rather than committing exclusively to one depth.
Sprint Hunting at Depth
The most dramatic hunting behavior pilot whales display happens near the bottom of their deepest dives. Short-finned pilot whales tagged off Tenerife performed daytime dives to depths between 540 and 1,019 meters. During many of these dives, the whales executed a rapid downward sprint just before producing a foraging buzz, hitting speeds of up to 9 meters per second. These sprints coincided with the deepest point of the dive, strongly suggesting a chase after escaping prey. Between 10% and 36% of the total locomotion cost of a deep dive was burned during these brief sprints, which lasted only 19 to 79 seconds out of a 15-minute dive.9PubMed. Cheetahs of the deep sea: deep foraging sprints in short-finned pilot whales off Tenerife (Canary Islands)
This is unusual for a deep-diving marine mammal. The conventional expectation is that animals working on a fixed oxygen budget should swim at moderate, energy-efficient speeds to maximize the time they can spend foraging at depth. Pilot whales break that rule, apparently betting that a short, expensive burst of speed aimed at a single large, fast-moving prey item will pay off in calories. The researchers who first described the behavior likened it to cheetahs on the African savanna: a high-risk, high-reward strategy focused on one target rather than grazing through a scattered cloud of small prey.9PubMed. Cheetahs of the deep sea: deep foraging sprints in short-finned pilot whales off Tenerife (Canary Islands) The suspected targets of these extreme sprints include large, fast squid, possibly even giant squid.
Long-finned pilot whales do it too, though perhaps not as often. Tagged long-finned pilot whales showed sprints exceeding 4.2 meters per second during about 24% of deep dives, often occurring at the end of the descent phase. Peak speeds during these bursts reached up to 9.3 meters per second. Roughly three-quarters of deep dives, however, contained no sprints at all, meaning the whales seem to rely on this tactic selectively.10Journal of Experimental Biology. High diving metabolic rate indicated by high-speed transit to depth in negatively buoyant long-finned pilot whales
Echolocation and the Final Approach
Pilot whales find prey in the dark depths using echolocation, emitting clicks that bounce off objects and return information about distance, size, and movement. As a whale closes in on a squid, its click rate increases dramatically, producing what researchers call a “buzz,” a rapid-fire train of clicks that functions like a targeting system during the last moments before capture. The presence and rate of these buzzes in tag data is one of the primary ways scientists identify when a whale is actually trying to catch something rather than just cruising through the water column.
Short-finned pilot whales also produce sounds called “rasps” during deep dives. These can be confused with foraging buzzes in acoustic recordings, but rasps are shorter and slower, and they are not accompanied by the sudden body accelerations or the reduced acoustic output that characterize genuine prey capture attempts. Rasps appear to serve a communication function rather than a hunting one.11Marine Mammal Science. Different modes of acoustic communication in deep‐diving short‐finned pilot whales (Globicephala macrorhynchus) Distinguishing between the two has been important for getting accurate estimates of how often and how successfully pilot whales forage during their dives.
Swallowing Without Biting
Once a pilot whale catches up to its prey, the capture itself relies on suction rather than biting. A kinematic study of long-finned pilot whales found that the ingestion sequence begins with a partial opening of the jaws, followed by a rapid depression of the hyoid bone, the large structure anchoring the tongue. The tongue acts like a piston, pulling backward and downward to create negative pressure inside the mouth. This suction is strong enough to draw in prey from a mean distance of about 14 centimeters in roughly 90 milliseconds, though prey were sometimes taken from greater distances. The food was normally ingested without the teeth grasping it at all. Instead, the whale used movements of its tongue, hyoid, and lower jaw to realign the squid and then sucked it into the back of the throat.12Marine Mammal Science. A Kinematic Study of Suction Feeding and Associated Behavior in the Long‐Finned Pilot Whale, Globicephala melas (Traill)
Suction feeding makes sense for an animal hunting slippery, soft-bodied squid in complete darkness. Teeth are useful for gripping, but a squid can tear free of a tooth grip more easily than it can escape a pressure differential. Pilot whales do have teeth, small and conical, but they seem to serve more as guides or occasional backup than as the primary capture tool. Several other deep-diving toothed whales that specialize on squid have also evolved reduced dentition, reinforcing the idea that suction is the dominant capture mode in this ecological niche.
How Much a Pilot Whale Needs to Eat
All that diving and sprinting requires a lot of fuel. A recent study estimated the daily energetic expenditure of short-finned pilot whales and worked backward to figure out how many squid an average adult needs. The answer: roughly 142 squid per day, or about 52,000 per year, to maintain a neutral energy balance. Each squid averaged about 559 kilojoules of energy content, based on beaks recovered from a stranded animal. Scaling that up to the estimated population of around 8,000 short-finned pilot whales in Hawaiian waters, the population as a whole would require approximately 416 million squid, or about 88,000 tonnes of squid annually.13PubMed. Daily energetic expenditure and energy consumption of short-finned pilot whales
Those numbers help explain why pilot whales concentrate in areas with reliably high squid density and why their movements often track oceanographic features like upwelling zones and deep scattering layers. A whale that misses a few days of successful deep foraging is running a caloric deficit that adds up fast.
Sharing the Deep Water with Other Hunters
Pilot whales are not the only toothed whales diving deep for squid. In the Bay of Biscay, the community of deep-diving odontocetes includes beaked whales, sperm whales, and several dolphin species. Stomach-content analysis showed that these predators partition the resource, each focusing on somewhat different squid families, depth zones, or habitats. Most species in the assemblage were almost exclusively squid-eaters, but the long-finned pilot whale was unusual in exploiting both pelagic oceanic and demersal neritic habitats, giving it access to a broader range of prey than its neighbors.4Deep Sea Research Part I: Oceanographic Research Papers. Prey preferences among the community of deep-diving odontocetes from the Bay of Biscay, Northeast Atlantic
This flexibility may reduce direct competition with more specialized deep divers like beaked whales, which tend to focus narrowly on particular squid families at particular depths. Pilot whales can shift their foraging to match what is locally abundant, whether that is a mesopelagic squid migrating upward at night or a bottom-dwelling octopus on the continental shelf.
Climate Change and Shifting Prey
Warming ocean temperatures are already reshuffling where pilot whale prey species live. In the northeast Atlantic, long-finned pilot whales have been shifting poleward in response to rising sea surface temperatures, but they have been doing so more than twice as fast as Atlantic mackerel and Atlantic herring, two prey species that also move with warming water.14PubMed Central. Trait-mediated shifts and climate velocity decouple an endothermic marine predator and its ectothermic prey The mismatch arises because the whales, as warm-blooded animals, can move independently of water temperature, while the cold-blooded fish and squid they eat track isotherms more closely. The result is a growing spatial gap between predator and prey.
What this means over the long term is unclear, but the pattern is concerning. If pilot whales move into waters where their preferred squid species have not yet arrived, they either need to find alternative prey or travel farther to forage. Either option carries energetic costs. Populations that are already nutritionally stressed or facing other pressures, such as noise disturbance or contaminant exposure, may be less able to absorb those costs.
Mercury Accumulation Through the Food Chain
Because pilot whales sit near the top of a deep-ocean food chain, they accumulate contaminants that have been concentrated at each step below them. Mercury is one of the most studied of these. Research on North Atlantic long-finned pilot whales used mercury stable isotopes to trace how different forms of mercury move through whale tissues. The study found that methylmercury, the most toxic organic form, and inorganic mercury could be tracked as two distinct isotopic signatures mixing in brain tissue. In adult whales with the highest methylmercury exposure, selenium-to-mercury ratios were lowest, suggesting that available selenium was being used up in the body’s effort to detoxify the mercury.15Deep Sea Research Part I: Oceanographic Research Papers. Selenium and stable mercury isotopes provide new insights into mercury toxicokinetics in pilot whales
This matters because selenium plays a protective role against mercury toxicity. When the supply runs low relative to the mercury load, the whale’s detoxification system is effectively overwhelmed. Pilot whales from the Faroe Islands, where they have been hunted for centuries, are among the most mercury-contaminated marine mammals ever tested, and health advisories have been issued for human consumption of pilot whale meat and blubber in the Faroes for this reason. The whales’ diet of deep-water squid, which itself has accumulated mercury from lower in the food web, is the primary pathway for this contamination.
How Researchers Figure Out What Pilot Whales Eat
Studying the diet of an animal that feeds hundreds of meters underwater in the open ocean is not straightforward. The traditional method is stomach-content analysis from stranded or hunted animals, which gives direct evidence of recent meals but has obvious sampling limitations: you only get data from animals that wash ashore or are killed. Beaks and otoliths accumulate over time, so stomach contents can overrepresent hard-bodied prey and undercount soft-bodied species that digest completely.
Fatty acid profiling has become an increasingly important complementary tool. Because certain fatty acids are incorporated into whale blubber relatively unchanged from the prey that supplied them, the blubber acts as a long-term dietary record. However, the method requires careful tissue selection. A study of long-finned pilot whales in the northeast Atlantic found that about 85% of identified fatty acids showed statistically significant differences in abundance between the epidermis (skin) and the blubber layers, confirming that skin biopsies are not interchangeable with blubber biopsies for dietary analysis.16Marine Biology. Neutral lipid fatty acid composition in the epidermis and blubber of long-finned pilot whales (Globicephala melas) in the Northeast Atlantic confirms tissue-specific stratification Polyunsaturated fatty acids linked to dietary intake were more abundant in the inner blubber layer, reinforcing that deep blubber samples are the gold standard for this technique.
Stable isotope analysis, which measures ratios of nitrogen and carbon isotopes in tissue, provides yet another angle. Nitrogen isotope ratios indicate how high in the food web an animal is feeding, while carbon ratios can distinguish between nearshore and offshore foraging. Combining all three methods, stomach contents for species identification, fatty acids for long-term dietary trends, and stable isotopes for trophic position, gives researchers a layered picture that no single technique could provide alone. The trade-off is that each method has its own biases and limitations, and interpreting them together requires careful calibration.