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What the sources say

Sperm WhalePhyseter macrocephalus

Every figure, record and mechanism on the Sperm Whale profile was written from a source, and this is the working table behind it: 54 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

NOAA Fisheries

Sperm Whale. NOAA Fisheries.

The page saysHunts on dives that routinely reach 610 meters
The source saysSperm whales hunt for food during deep dives that routinely reach depths of 2,000 feetNote: 610 m from 2,000 feet (609.6 m). A routine depth, worded as one, not a maximum.
The page saysAll of the world's deep oceans, from the equator to the edge of the polar pack ice
The source saysThey are found in all deep oceans, from the equator to the edge of the pack ice in the Arctic and Antarctic.
The page saysplus sharks, skates, and other deep-sea fish
The source saystheir diet consists of species such as squid, sharks, skates, and fish that also occupy deep ocean waters
The page saysan oil sac of spermaceti that helps focus the sound
The source saysThe spermaceti is an oil sac that helps the whales focus sound.
The page sayssperm whales hunt on deep dives that routinely reach 2,000 feet (610 meters) and can last 45 minutes
The source saysSperm whales hunt for food during deep dives that routinely reach depths of 2,000 feet and can last for 45 minutes.Note: 610 m from 2,000 feet.
The page saysthe whale comes up to breathe and recover at the surface for several minutes before diving again
The source saysAfter long, deep dives, individuals come to the surface to breathe and recover for several minutes before initiating their next dive.
The page saysNOAA Fisheries describes the spermaceti as an oil sac that helps the whale focus sound
The source saysThe spermaceti is an oil sac that helps the whales focus sound.
The page saysPeople once used spermaceti in oil lamps, lubricants and candles
The source saysSpermaceti was used in oil lamps, lubricants, and candles.
The page saysis the largest of the toothed whales
The source saysSperm whales are the largest of the toothed whales
The page saysit lives in deep oceans worldwide, from the equator to the edge of the polar pack ice
The source saysThey are found in all deep oceans, from the equator to the edge of the pack ice in the Arctic and Antarctic.
The page saysAdults weigh from 15 tons (females) to 45 tons (males)
The source says15 tons (females) to 45 tons (males)Note: NOAA quick facts. US tons, left unconverted.
The page saysmales grow to about 52 feet (16 meters)
The source saysMales reach physical maturity around 50 years and when they are approximately 52 feet long.Note: 52 ft = 15.8 m. NOAA's female figures disagree with each other (40 feet in quick facts, 'up to 35 feet' in the text), so the page gives no female length.
The page saysa sperm whale can live up to 60 years
The source saysUp to 60 years
The page saysIt hunts on deep dives that routinely reach 2,000 feet (610 meters) and can last 45 minutes
The source saysSperm whales hunt for food during deep dives that routinely reach depths of 2,000 feet and can last for 45 minutes.Note: 610 m from 2,000 feet.
The page saysthen comes up to breathe and recover for several minutes before the next one
The source saysAfter long, deep dives, individuals come to the surface to breathe and recover for several minutes before initiating their next dive.
The page sayssharks, skates and other deep-sea fish are on the menu too
The source saystheir diet consists of species such as squid, sharks, skates, and fish that also occupy deep ocean waters
The page saysthe spermaceti, an oil sac in the head, helps focus the sound
The source saysfound in their heads. The spermaceti is an oil sac that helps the whales focus sound.
The page saysCommercial whaling from 1800 to the 1980s greatly reduced their numbers worldwide.
The source saysCommercial whaling from 1800 to the 1980s greatly decreased sperm whale populations worldwide.
The page saysThe species is still recovering, and its numbers are likely increasing.
The source saysThe species is still recovering, and its numbers are likely increasing.
The page saysBiggest of the Toothed Whales
The source saysSperm whales are the largest of the toothed whalesNote: section heading

Source
02

Møhl et al. 2003

Møhl et al. (2003). The monopulsed nature of sperm whale clicks. The Journal of the Acoustical Society of America.

The page saysfires biosonar clicks up to 236 decibels underwater
The source sayssource levels up to 236 dB re: 1 microPa (rms) ... Such clicks meet the requirements for long-range biosonar purposes.Note: dB re 1 microPa is the underwater reference level, so 'underwater' is kept: the figure is not comparable to decibels in air.
The page saysfires echolocation clicks up to 236 decibels underwater
The source sayssource levels up to 236 dB re: 1 microPa (rms)Note: Underwater reference level (re 1 microPa), so 'underwater' stays: the figure is not comparable to decibels in air.
The page saysthe loudest sounds known from any animal
The source saysThe sound levels measured make sperm whale clicks by far the loudest of sounds recorded from any biological source.Note: 'known' for 'recorded'. The newer Fais et al. (2016) restates the record: 'the highest instantaneous sound levels from any known biological sound source' and 'Sperm whales produce the most powerful biological sounds in the animal kingdom'.
The page saysSperm whale clicks are the loudest sounds recorded from any animal.
The source saysThe sound levels measured make sperm whale clicks by far the loudest of sounds recorded from any biological source.
The page saysA study off Norway measured clicks judged to be aimed head-on at up to 236 decibels underwater
The source saysA limited number of assumed on-axis clicks were recorded ... with source levels up to 236 dB re: 1 microPa (rms) ... Data were obtained with a large-aperture, GPS-synchronized array in July 2000 in the Bleik Canyon off Vesterålen, NorwayNote: 'judged to be aimed head-on' keeps the paper's 'assumed on-axis'.
The page saysand concluded they suit long-range biosonar
The source saysSuch clicks meet the requirements for long-range biosonar purposes.
The page saysIn recordings off Norway, clicks judged to be aimed straight at the recording array reached up to 236 decibels underwater
The source saysA limited number of assumed on-axis clicks were recorded ... with source levels up to 236 dB re: 1 microPa (rms) ... Data were obtained with a large-aperture, GPS-synchronized array in July 2000 in the Bleik Canyon off Vesterålen, NorwayNote: 'judged to be aimed straight at' keeps 'assumed on-axis'; re 1 microPa is the underwater reference.
The page saysby far the loudest sounds recorded from any biological source
The source saysThe sound levels measured make sperm whale clicks by far the loudest of sounds recorded from any biological source.

Source
03

Fais et al. 2016

Fais et al. (2016). Sperm whale predator-prey interactions involve chasing and buzzing, but no acoustic stunning. Scientific Reports.

The page saysoccasionally swallows giant and colossal squid
The source saysOccasionally, much larger squid such as jumbo, giant and colossal squid ... have been found in sperm whale stomachsNote: Stomach contents show the squid were swallowed, not how they were caught, so the tagline no longer calls the whale a 'hunter' of them.
The page saysMostly medium-sized squid, with occasional jumbo, giant, and colossal squid
The source saysThe main food source for sperm whales are medium sized squid (0.5 m and 1–3 kg) ... Occasionally, much larger squid such as jumbo, giant and colossal squid
The page saysA gigantic nose that fires echolocation clicks
The source saysThe sperm whale carries a hypertrophied nose that generates powerful clicks for long-range echolocation. ... the gigantic nose of sperm whales
The page saysA 2016 study that tagged six whales found no sign that the clicks stun prey
The source saysHere we use high resolution sound and movement recording tags on free-ranging sperm whales to quantify their behaviour during prey captures. ... We also show that sperm whales do not debilitate prey acoustically ... the 6 tagged sperm whalesNote: Published 2016 (Scientific Reports); six = the 6 tagged whales, three off the US East coast and three off northern Norway.
The page saysin the final stage of an attack, the whales turned their clicks down by 20 to 40 decibels
The source saysThe tagged sperm whales reduced their ICIs by more than an order of magnitude when switching from usual to buzz clicking ( Fig. 4A,B ). Simultaneously they reduced the output level of their clicks by 20–40 dBNote: The buzz is the terminal phase of prey capture ('in the terminal buzz phase', abstract).
The page saysleaving the sound at the prey far below the level needed to stun it
The source saysInstead they dramatically reduce source levels when they are within a body length of their prey resulting in exposure levels that are 1 to 2 orders of magnitude below those required to debilitate prey.
The page saysin a 2016 tagging study, three adult males off northern Norway
The source sayswhereas all three whales tagged off northern Norway were adult male sperm whalesNote: Published 2016.
The page saysforaged as deep as 1,862 meters (about 6,100 feet)
The source saysWhales foraging in the high latitude habitat switched between shallow (48–217 m) and deeper (253–1862 m) foraging layers.Note: 1,862 m = 6,109 ft. 'High latitude habitat' is the Norway site. The deepest foraging layer of three tagged males, not a species maximum, so the answer frames it as one study's figure.
The page saysin old males that blunt head can be up to a third of the body's length
The source saysThe body plan of sperm whales is dominated by a bluff-fronted head that, in old males, may constitute up to 1/3 of the body lengthNote: Replaces NOAA's general 'about one-third', which Fais et al. restrict to old males and Clarke (1978) puts at more than a quarter.
The page saysIn old males, the blunt-fronted head can make up to a third of the body's length.
The source saysa bluff-fronted head that, in old males, may constitute up to 1/3 of the body length
The page saysIts main food is medium-sized squid, around half a meter long and 1 to 3 kilograms each.
The source saysThe main food source for sperm whales are medium sized squid (0.5 m and 1–3 kg)
The page saysMuch bigger jumbo, giant and colossal squid have occasionally turned up in sperm whale stomachs
The source saysOccasionally, much larger squid such as jumbo, giant and colossal squid ... have been found in sperm whale stomachs
The page saysIt finds that food by echolocation, listening for the echoes of its own clicks.
The source saysSperm whales produce the most powerful biological sounds in the animal kingdom in order to echolocate prey at long ranges
The page saysThose clicks come from a gigantic nose
The source saysThe sperm whale carries a hypertrophied nose that generates powerful clicks for long-range echolocation. ... the gigantic nose of sperm whales
The page saysA hypothesis nicknamed the "biological big bang" proposed that the whale stuns its prey with those clicks.
The source saysadvanced the so-called biological big bang hypothesis suggesting that the powerful usual clicks of sperm whales serve to acoustically debilitate prey and thereby facilitate capture
The page saysA 2016 study tested it with sound-and-motion tags on six whales.
The source saysa specific test of the different ... hypotheses require fine scale data ... Here we use high resolution sound and movement recording tags on free-ranging sperm whales ... the 6 tagged sperm whalesNote: Published 2016; six = 6.
The page saysAbout a body length from their prey, the tagged whales switched to a fast buzz of clicks and turned them down by 20 to 40 decibels
The source saysThe tagged sperm whales reduced their ICIs by more than an order of magnitude when switching from usual to buzz clicking ( Fig. 4A,B ). Simultaneously they reduced the output level of their clicks by 20–40 dB ... At a mean estimated distance of 9 meters to the prey, the tagged sperm whales switched from the approach to the buzz phase. This hand-off distance is about a body length of a female sperm whaleNote: The conclusion puts it the same way: whales 'reduce acoustic outputs by several orders of magnitude when they are about their own body length from their prey'.
The page saysso the sound reaching the prey stayed far below what it takes to stun it
The source saysInstead they dramatically reduce source levels when they are within a body length of their prey resulting in exposure levels that are 1 to 2 orders of magnitude below those required to debilitate prey.
The page saysThe quiet, rapid clicks give the whale fast updates on where its prey is
The source saysbuzzing involves high-frequency, low amplitude clicks well suited to provide high-resolution biosonar updates during the last stages of capture
The page sayssudden jolts recorded near the end of most buzzes
The source saysstrong transients of jerk were found around 5 seconds before the end of the majority of buzzesNote: 'most' for 'the majority of'; jerk transients are sudden changes in acceleration.
The page sayspoint to fast jaw movements, suction or both to catch it
The source saysprey are eventually subdued with the aid of fast jaw movements and/or buccal suction as indicated by acceleration transients (jerks) near the end of buzzes
The page saysSperm whales are major nutrient recyclers in the world's oceans
The source saysa major nutrient recycler in the world ... responsible for an annual biomass turnover that has been compared to the combined catches of human fisheries
The page saysthe prey they get through each year has been compared to the combined catch of human fisheries
The source saysresponsible for an annual biomass turnover that has been compared to the combined catches of human fisheriesNote: 'annual biomass turnover' put as the prey they get through each year.

Source
04

IUCN SSC Cetacean Specialist Group

Red List Status of Cetaceans. IUCN SSC Cetacean Specialist Group.

The page saysVulnerable
The source saysSeven species are classified as Vulnerable: Fin whales (Balaenoptera physalus) , Indo-Pacific finless porpoises (Neophocaena phocaenoides) , Australian snubfin dolphins (Orcaella heinsohni) , Sperm whales (Physeter macrocephalus)Note: IUCN SSC Cetacean Specialist Group status page, 'Updated October 2025', against Red List version 2025-2. iucnredlist.org refuses scripts.
The page saysthe IUCN lists it as Vulnerable
The source saysSeven species are classified as Vulnerable: Fin whales (Balaenoptera physalus) , Indo-Pacific finless porpoises (Neophocaena phocaenoides) , Australian snubfin dolphins (Orcaella heinsohni) , Sperm whales (Physeter macrocephalus)

Source
05

Clarke 1978

Clarke (1978). Structure and Proportions of the Spermaceti Organ in the Sperm Whale. Journal of the Marine Biological Association of the United Kingdom.

The page saysan oil-filled organ that makes up a large part of the sperm whale's head
The source saysthe spermaceti oil, which is the most remarkable component and constitutes a large proportion of the head

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.