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What the sources say

Blue WhaleBalaenoptera musculus

Every figure, record and mechanism on the Blue Whale profile was written from a source, and this is the working table behind it: 58 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

Blue Whale. NOAA Fisheries.

The page saysThe largest animal that has ever lived
The source saysthey are the largest animals ever to live on our planet.
The page saysrated among the loudest animals on the planet
The source saysThey are among the loudest animals on the planet
The page saysAll oceans except the Arctic
The source saysBlue whales are found in all oceans except the Arctic.
The page saysblue whales generally spend summers feeding in polar waters and migrate toward the equator as winter arrives
The source saysThey generally spend summers feeding in polar waters and undertake lengthy migrations towards the equatorial waters as winter arrives.
The page saysAlmost exclusively krill, strained from huge mouthfuls of ocean water through baleen plates
The source saysThey feed almost exclusively on krill, straining huge volumes of ocean water through their baleen plates (which hang from the roof of the mouth and work like a sieve).
The page sayssome of the biggest whales can eat up to 6 tons a day
The source saysSome of the biggest individuals may eat up to 6 tons of krill a day.
The page saysthought to carry up to 1,000 miles in the right ocean conditions
The source saysit is thought that in the right oceanographic conditions, sounds emitted by blue whales can be heard by other whales up to 1,000 miles away
The page saysThe Biggest Animal There Has Ever Been
The source saysthey are the largest animals ever to live on our planet.Note: heading; same NOAA line as the tagline claim.
The page saysNOAA Fisheries calls it "the largest animal on Earth"
The source saysThe blue whale is the largest animal on Earth.
The page saysand "the largest animals ever to live on our planet."
The source saysthey are the largest animals ever to live on our planet.
The page saysNOAA Fisheries records blue whales at up to 110 feet long and 330,000 pounds
The source saysWeight Up to 330,000 pounds ... Length Up to 110 feet
The page saysA blue whale's average lifespan is estimated at around 80 to 90 years
The source saysBlue whales’ average lifespan is estimated at around 80 to 90 years.
The page saysdecades after commercial whaling in the early 1900s cut its numbers to a small fraction of what they were
The source saysThe number of blue whales today is only a small fraction of what it was before modern commercial whaling significantly reduced their numbers during the early 1900s
The page saysBlue whales eat almost exclusively krill, tiny shrimp-like animals
The source saysThey feed almost exclusively on krill ... The primary diet of blue whales is krill—tiny shrimp-like animals
The page saysstrained out of huge mouthfuls of seawater through baleen plates that hang from the roof of the mouth
The source saysstraining huge volumes of ocean water through their baleen plates (which hang from the roof of the mouth and work like a sieve)
The page saysSome of the biggest whales can eat up to 6 tons of krill a day, according to NOAA Fisheries.
The source saysSome of the biggest individuals may eat up to 6 tons of krill a day.
The page sayslunges into a school of krill with its mouth open, its pleated throat ballooning outward to trap water and prey together, then pushes the water back out through the baleen with its tongue while the krill stays trapped behind
The source saysswimming toward large schools of krill with their mouths open and closing their mouths around the krill while inflating their throat pleats. Once closed, blue whales then push the trapped water out of their mouth with their tongue and use their baleen plates to keep the krill trapped inside.Note: 'lunges' for NOAA's 'swimming toward': this is lunge feeding, named as such in mechanics-2011 and blue-2015.
The page saysFemales are generally the larger sex
The source saysLike many other baleen whales, female blue whales are generally larger than males.
The page saysCalves are born mostly in winter
The source saysMost reproductive activity, including births and mating, takes place during the winter.
The page saysa female's average calving interval is estimated at 2 to 3 years
The source saysThe average calving interval is estimated to be 2 to 3 years.
The page saysOne Of The Loudest Voices In The Ocean
The source saysThey are among the loudest animals on the planetNote: heading
The page saysNOAA Fisheries counts blue whales among the loudest animals on the planet.
The source saysThey are among the loudest animals on the planet
The page saysNOAA Fisheries says those calls are thought to carry up to 1,000 miles in the right ocean conditions.
The source saysit is thought that in the right oceanographic conditions, sounds emitted by blue whales can be heard by other whales up to 1,000 miles away
The page saysScientists think whales use them to communicate and maybe to navigate the dark ocean depths by sonar.
The source saysScientists think they use these vocalizations to communicate and ... perhaps to sonar-navigate the dark ocean depths.
The page saysSome of the biggest blue whales can eat up to 6 tons of krill a day, according to NOAA Fisheries.
The source saysSome of the biggest individuals may eat up to 6 tons of krill a day.
The page sayslunging into a school of krill with its mouth open, closing its jaws around the krill while its pleated throat balloons outward to trap water and prey together, then pushing the water back out through its baleen plates with its tongue while the krill stays trapped inside
The source saysswimming toward large schools of krill with their mouths open and closing their mouths around the krill while inflating their throat pleats. Once closed, blue whales then push the trapped water out of their mouth with their tongue and use their baleen plates to keep the krill trapped inside.Note: 'lunging' for NOAA's 'swimming toward': this is lunge feeding, named as such in mechanics-2011 and blue-2015.
The page saysNOAA Fisheries counts blue whales among the loudest animals on the planet.
The source saysThey are among the loudest animals on the planet
The page saysAs far as scientists can tell, yes.
The source saysthey are the largest animals ever to live on our planet.Note: The source states it flatly; the answer is weaker, not stronger. downsizing-2024 names 'the challenges and difficulties of measuring extant and extinct candidates for the largest animal of all time'.
The page saysThe blue whale (Balaenoptera musculus) is, as far as anyone can tell, the biggest animal that has ever lived
The source saysthey are the largest animals ever to live on our planet.Note: same NOAA line as the tagline/heading claims; 'biggest' paraphrases 'largest'.
The page saysNOAA Fisheries names vessel strikes and entanglement in fishing gear as the primary threats blue whales face today.
The source saysThe primary threats blue whales currently face are vessel strikes and entanglements in fishing gear.

Source
02

Animal Diversity Web, University of Michigan

Balaenoptera musculus (blue whale). Animal Diversity Web, University of Michigan.

The page saysAnimal Diversity Web lists no negative impacts of blue whales on humans.
The source saysThere are no negative impacts of blue whales on humans.Note: added in the #229 settle so the page states what backs stats.dangerLevel Low ('Effectively harmless to people'). ADW's account dates from 2002; the current NOAA page (updated 2026-07) reports no harm to people either, only whales harmed by vessels.

Source
03

Cooke 2018

Cooke (2018). Balaenoptera musculus. The IUCN Red List of Threatened Species 2018: e.T2477A156923585.

The page saysthe species is still listed as Endangered by the IUCN Red List
The source saysIUCN Red List category: Endangered (EN).

Source
04

Motani & Pyenson 2024

Motani & Pyenson (2024). Downsizing a heavyweight: factors and methods that revise weight estimates of the giant fossil whale Perucetus colossus. PeerJ.

The page saysThe longest blue whale reliably measured, a female, came in at 33.26 meters (109.12 feet)
The source saysthe longest reliably measured blue whale was a female 33.26 m long (109.12 feet long; see Risting, 1928)
The page saysa 2024 study built to test whether an ancient fossil whale called Perucetus colossus was heavier concluded that it wasn't
The source saysWe conclude that Perucetus did not exceed the body mass of today’s blue whales.Note: Year (2024) comes from the reference's own publication year, not the quoted sentence. Bianucci et al. (2023) had proposed Perucetus at 85-340 tons, 'rivaling or exceeding the mass of the largest blue whales'; this paper re-examined that estimate and rejected it.
The page saysThe longest blue whale reliably measured was a female 33.26 meters (109.12 feet) long.
The source saysthe longest reliably measured blue whale was a female 33.26 m long (109.12 feet long; see Risting, 1928)
The page saysA 2023 study suggested a giant fossil whale called Perucetus colossus might rival or outweigh the largest blue whales
The source saysBianucci et al. (2023) suggested it was the heaviest whale ever, possibly reaching 17 to 20 m in length and 85 to 340 tons in total weight, rivaling or exceeding the mass of the largest blue whales.
The page saysa detailed 2024 study built to test that claim concluded that Perucetus did not outweigh today's blue whales
The source saysWe conclude that Perucetus did not exceed the body mass of today’s blue whales.Note: Year (2024) is the reference's publication year. 'that claim': the paper set out 'to validate the implication by Bianucci et al. (2023) that Perucetus was larger than the largest blue whales'.

Source
05

Branch & Monnahan 2020

Branch & Monnahan (2020). Sex ratios in blue whales from conception onward: effects of space, time, and body size. Marine Mammal Science.

The page saysAntarctic blue whale calves are born at about 7 meters (23 feet) long
The source saysFew published data are available to estimate length at age for Antarctic blue whales, but there are some indications of length at key ages. Males and females are born at 7.0 m (23 ft)
The page saysa 2020 study of whaling records
The source saysWe assessed blue whale ( Balaenoptera musculus ) sex ratios based on 21,542 fetal and 311,901 whaling recordsNote: Year (2020) is the reference's publication year.
The page sayssays they are weaned just 7 months later at around 16 meters (52.5 feet), more than double their birth length
The source saysand weaned 7 months later at 16.0 m (52.5 ft)Note: 'says', not 'found': the paper cites the lengths from Mackintosh & Wheeler (1929). 16/7 is ~2.3x, 'more than double' follows from the two quoted lengths.
The page saysan Antarctic female reaches sexual maturity at around 23.7 meters long, at about age 10
The source saysFemale Antarctic blue whales reach sexual maturity at ~23.7 m (77.8 ft) ... both at age 10 years
The page saysAn Antarctic blue whale calf is born at about 7 meters (23 feet) long
The source saysFew published data are available to estimate length at age for Antarctic blue whales, but there are some indications of length at key ages. Males and females are born at 7.0 m (23 ft)
The page saysa 2020 study of whaling records
The source saysWe assessed blue whale ( Balaenoptera musculus ) sex ratios based on 21,542 fetal and 311,901 whaling recordsNote: Year (2020) is the reference's publication year.
The page sayssays it is weaned just 7 months later at around 16 meters (52.5 feet), more than double its birth length in under a year
The source saysand weaned 7 months later at 16.0 m (52.5 ft)Note: 7 months is under a year; 16/7 is ~2.3x.
The page saysA Calf That Doubles In Length Before Weaning
The source saysMales and females are born at 7.0 m (23 ft) and weaned 7 months later at 16.0 m (52.5 ft)Note: heading; 'doubles' is the writer's arithmetic on the two quoted lengths (16/7 is ~2.3x), already covered as a body claim. 'Before': the calf passes double its birth length (14 m) before reaching its 16 m weaning length.

Source
06

Širović, Hildebrand & Wiggins 2007

Širović, Hildebrand & Wiggins (2007). Blue and fin whale call source levels and propagation range in the Southern Ocean. The Journal of the Acoustical Society of America.

The page saysCalls measured off Antarctica averaging 189 decibels at 25 to 29 Hz
The source saysThe source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated ... the average blue whale call source level was 189+/-3 dB re:1 microPa-1 m over 25-29 Hz
The page saysRecordings made off the Antarctic Peninsula measured their calls averaging 189 decibels in a low rumble between 25 and 29 Hz.
The source saysThe source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated using recordings made with calibrated, bottom-moored hydrophones. ... the average blue whale call source level was 189+/-3 dB re:1 microPa-1 m over 25-29 Hz
The page saysRecordings made off the Antarctic Peninsula measured blue whale calls averaging 189 decibels in a low rumble between 25 and 29 Hz
The source saysThe source levels of blue and fin whale calls off the Western Antarctic Peninsula were calculated using recordings made with calibrated, bottom-moored hydrophones. ... the average blue whale call source level was 189+/-3 dB re:1 microPa-1 m over 25-29 Hz
The page saysthe same hydrophones located calling blue whales up to 200 kilometers (about 124 miles) away
The source saysBlue whales were located up to a range of 200 km using hyperbolic localization and time difference of arrival.Note: 200 km is 124.3 miles. The whales were located from their own calls (hyperbolic localization on call arrival times at the hydrophones).

Source
07

Nieukirk et al. 2004

Nieukirk et al. (2004). Low-frequency whale and seismic airgun sounds recorded in the mid-Atlantic Ocean. The Journal of the Acoustical Society of America.

The page saysHydrophones in the mid-Atlantic picked up an even deeper sound that researchers attribute to blue whales: a two-part moan at roughly 18 Hz that lasts 25 seconds.
The source saysan array of six autonomous hydrophones was moored near the Mid-Atlantic Ridge ... (1) a two-part low-frequency moan at roughly 18 Hz lasting 25 s which has previously been attributed to blue whales (Balaenoptera musculus)Note: added in the #174 settle: this is what backs the infrasound tag (tagMetadata: 'below 20 Hz'); the Antarctic 25-29 Hz calls are above that line. ADW (54f8d308a6dbe89d) agrees: 'vocalizing as low as 14 Hz'.

Source
08

Hazen, Friedlaender & Goldbogen 2015

Hazen, Friedlaender & Goldbogen (2015). Blue whales (Balaenoptera musculus) optimize foraging efficiency by balancing oxygen use and energy gain as a function of prey density. Science Advances.

The page saysOne Gulp, Eighty Cubic Meters of Ocean
The source saysa blue whale can engulf about 80 m 3 of prey-laden water in 7 sNote: heading; 'eighty' from the same figure as the blockquote.
The page saysEighty Cubic Meters in Seven Seconds
The source saysa blue whale can engulf about 80 m 3 of prey-laden water in 7 s
The page saysThat's how much water and krill a blue whale can gulp down in a single lunge, more than three times faster than a continuously feeding bowhead whale manages the same volume.
The source saysa blue whale can engulf about 80 m 3 of prey-laden water in 7 s, whereas a continuously ram-feeding bowhead whale would require 25 s to filter the same target volume ... a blue whale could therefore consume an entire 80-m 3 prey patch in a single gulpNote: 25s / 7s is more than 3x.
The page saysTagged whales even switch strategy to match the krill
The source sayswe empirically show that blue whales switch between time-minimizing and energy-maximizing foraging strategies as a function of prey density
The page saystwo or three lunges per dive to conserve oxygen when krill are sparse, then four to eight per dive to maximize energy on denser patches
The source saysblue whales foraging on low krill densities fed at low rates (two to three lunges per dive), aligning with the predicted oxygen-conserving strategy, but increased their feeding rates (four to eight lunges per dive) when foraging on denser patches ... the blue whales appeared to switch between oxygen-conserving and energy-maximizing foraging strategies as a function of krill density
The page saysbuilt to gulp krill-laden water by the ton
The source saysa blue whale can engulf about 80 m 3 of prey-laden water in 7 sNote: tagline; 80 cubic meters of seawater weighs about 80 tonnes, so one gulp is dozens of tons.

Source
09

Goldbogen et al. 2011

Goldbogen et al. (2011). Mechanics, hydrodynamics and energetics of blue whale lunge feeding: efficiency dependence on krill density. Journal of Experimental Biology.

The page saysLunge feeding like this comes with a high energetic cost.
The source saysLunge feeding by rorqual whales (Balaenopteridae) is associated with a high energetic cost that decreases diving capacity
The page saysresearchers who tagged foraging blue whales estimated their foraging efficiency runs nearly ten times higher than other marine mammals', but only when they lunge into extremely dense krill
The source sayswe integrated kinematic data from digital tags with unsteady hydrodynamic models to estimate the energy budget for lunges and foraging dives of blue whales ... foraging efficiency for blue whales is significantly higher than for other marine mammals by nearly an order of magnitude, but only if lunges target extremely high densities of krillNote: 'order of magnitude' rendered as 'nearly ten times'.

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.