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What the sources say

Common KingfisherAlcedo atthis

Every figure, record and mechanism on the Common Kingfisher profile was written from a source, and this is the working table behind it: 41 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

Animal Diversity Web, University of Michigan

Alcedo atthis (common kingfisher). Animal Diversity Web, University of Michigan.

The page saysan underwater strike made by touch alone
The source saysthey rely solely on touch to know when to snap their jaws shutNote: tagline; the colour words are description, the factual half is ADW's touch-only strike.
The page saysMostly small fish such as minnows, plus freshwater shrimp-like crustaceans and aquatic insects
The source saysCommon kingfishers eat mostly small fish, making up 60-67% of their diet. ... Animal Foods: fish, insects, aquatic crustaceans, other marine invertebratesNote: stats.diet field; same source and reasoning as the body's diet sentence. 'Mostly' restored from the source.
The page saysAfter catching a fish, a kingfisher carries it back to a perch, grips it by the tail and whacks it against the perch.
The source saysAfter catching a fish, common kingfishers will hold the prey by its tail, and whack it against the perch.
The page sayshunts from a perch that can be anywhere from several centimetres to several metres above the water
The source saysCommon kingfishers hunt for prey from a perch above the water. Perches may be several centimeters to several meters above the water.
The page sayslight bends at a different angle passing from air into water, an effect called refraction, and a kingfisher learns to compensate for that shift, which helps it catch prey more effectively
The source saysThey also learn to compensate for refraction, allowing them to catch prey more effectively.Note: 'light bends at a different angle passing from air into water' is the standard definition of refraction, explained for young readers on first use; the source names the effect ('compensate for refraction') without spelling out the physics.
The page saysa third eyelid called a nictitating membrane closes over each eye, and the bird finishes the job blind: it relies on touch alone to know the moment to snap its bill shut on the fish
The source saysIn a dive for prey, a membrane covers their eyes and they rely solely on touch to know when to snap their jaws shut.Note: 'third eyelid' and 'nictitating membrane' are the standard names for the membrane ADW describes (rspb-kingfisher calls it 'a transparent third eyelid'); the page does not call it transparent, because the source that does says it helps the bird keep sight of its target, while ADW says the strike is finished by touch.
The page saysA blind strike. It compensates for the way light bends where air meets water, then closes a third eyelid over each eye and relies on touch alone to time the snap of its bill.
The source saysThey also learn to compensate for refraction, allowing them to catch prey more effectively. ... In a dive for prey, a membrane covers their eyes and they rely solely on touch to know when to snap their jaws shut.Note: stats.superpower restates the refraction-correction and touch-strike claims above, bridging two non-adjacent ADW sentences with ...
The page saysLight bends at a different angle passing from air into water, an effect called refraction, and a common kingfisher learns to compensate for that shift, which helps it catch prey more effectively.
The source saysThey also learn to compensate for refraction, allowing them to catch prey more effectively.Note: FAQ 1's opening sentence; same source and reasoning as the body claim above.
The page saysthe instant it hits the surface, a third eyelid called a nictitating membrane closes over each eye, and the bird finishes the strike blind, relying on touch alone to know the moment to snap its bill shut
The source saysIn a dive for prey, a membrane covers their eyes and they rely solely on touch to know when to snap their jaws shut.
The page saysA kingfisher eats around 60% of its own body weight every day
The source saysThis is mainly because they must eat around 60% of their body weight each day.
The page sayswhich is mainly why it is fiercely territorial, defending its patch of water against rivals, its mate and even its own offspring
The source saysCommon kingfishers are very territorial ... This is mainly because they must eat around 60% of their body weight each day. They will even defend their area from their mates and offspring.Note: bridges two sentences with ...; 'fiercely' is voice for 'very territorial'.
The page saysmeasures about 17 centimetres long
The source saysAverage length 17 cm
The page saysIts diet is mostly small fish, including minnows, plus freshwater shrimp-like crustaceans and aquatic insects
The source saysCommon kingfishers eat mostly small fish, making up 60-67% of their diet. ... Animal Foods: fish, insects, aquatic crustaceans, other marine invertebratesNote: 'shrimp-like' glosses ADW's amphipod crustacean prey (Gammarus fasciatus) for readers.
The page saysAfter a catch, the bird carries the fish back to its perch, grips it by the tail and whacks it against the perch. That stuns or kills it, which is particularly important with spiny fish
The source saysAfter catching a fish, common kingfishers will hold the prey by its tail, and whack it against the perch. This stuns or kills the prey, which is particularly important when eating fish with spines.
The page saysAnything it cannot digest comes back up later as a pellet of bone
The source saysAfter consuming a fish it will regurgitate a pellet of indigestible bone.
The page saysCommon kingfishers live along clear, slow-moving rivers, canals and ponds from Britain and Ireland across Europe and Asia as far east as Japan, and through Africa south of the Sahara
The source saysAlcedo atthis is found throughout Europe and Asia as far east as Japan. They are also found in Africa, south of the Sahara.Note: 'Britain and Ireland' and 'clear, slow-moving rivers, canals and ponds' come from rspb-kingfisher ('You can find them on most rivers, canals and lakes across the UK... They particularly like places where the water is clear or slow flowing') and bto-birdfacts-kingfisher ('Kingfishers are widely distributed on the lowland rivers of Britain & Ireland').
The page saysSouthern birds stay put all year, while northern populations move south in winter to escape freezing water
The source saysCommon kingfishers are year long residents in their southern habitats, while northern populations travel south during the winter to escape freezing water.
The page saysNumbers swing hard from one year to the next, mostly because of severe cold
The source sayscommon kingfishers do undergo large fluctuations in populations on a yearly basis. This is due mostly to severe cold.
The page saysone census in Belgium counted 8 pairs after a severe winter, 45 five years later, and 25 the year after that
The source saysIn one census, after a severe winter in Belgium there were only 8 pairs, five years later there were 45, but reduced to 25 the following year.
The page saysThat stuns or kills the fish, which is particularly important when the prey has spines
The source saysThis stuns or kills the prey, which is particularly important when eating fish with spines.
The page saysOnce the fish is swallowed, anything the kingfisher cannot digest comes back up later as a pellet of bone
The source saysAfter consuming a fish it will regurgitate a pellet of indigestible bone.
The page saysRivers Across Three Continents
The source saysAlcedo atthis is found throughout Europe and Asia as far east as Japan. They are also found in Africa, south of the Sahara.Note: heading counts the three continents (Europe, Asia, Africa) named in the range claim above; arithmetic, not a new figure.
The page saysa membrane covers each eye as it hits the water, and it relies on touch alone to know when to snap its bill shut
The source saysIn a dive for prey, a membrane covers their eyes and they rely solely on touch to know when to snap their jaws shut.Note: vibe.reason, settled in task #635
The page saystags: hyperactive
The source saysThis is mainly because they must eat around 60% of their body weight each day.Note: tag moved from the chinstrap penguin (task #635): the definition is metabolic demand forcing relentless foraging

Source
02

British Trust for Ornithology

BirdFacts: Kingfisher (Alcedo atthis). British Trust for Ornithology.

The page saysAn adult weighs around 39 grams
The source saysAll adults 39.1±3.5 g (34.5-45.5 g, N=554)Note: 39.1 g rounded to 39 g; the current BTO ringing figure is preferred over ADW's older 34 g average.
The page saysUK ringing data collected by the British Trust for Ornithology show about 21.5% of young kingfishers survive their first year
The source saysSurvival of juveniles All juveniles 0.215 (in first year)Note: 0.215 converted to 21.5%.
The page saysa bird that reaches breeding age has a typical life expectancy of two years
The source saysTypical life expectancy of bird reaching breeding age 2 years with breeding typically at 1 yearNote: BTO gives the figure as '2 years' for a bird reaching breeding age; the page states it as two years rather than two further years.
The page saysthe oldest in the BTO's ringing records reached 4 years, 6 months and 29 days
The source saysMaximum age from a ringed bird 4 years, 6 months, 29 days (set in 2012)Note: scope kept to the BTO's own ringing records, which is what the page reports.
The page saysThe oldest bird in the BTO's ringing records reached 4 years, 6 months and 29 days, in 2012.
The source saysMaximum age from a ringed bird 4 years, 6 months, 29 days (set in 2012)Note: FAQ 3's closing sentence.
The page saysthe UK's breeding population was stable from 1995 to 2024
The source saysPopulation Change Stable 1995 to 2024
The page saysRinging data collected by the British Trust for Ornithology puts first-year survival at about 21.5 percent, and a bird that reaches breeding age has a typical life expectancy of two years.
The source saysTypical life expectancy of bird reaching breeding age 2 years with breeding typically at 1 year ... Survival of juveniles All juveniles 0.215 (in first year)Note: 0.215 converted to 21.5%; bridges two non-adjacent BTO stats with ... (life-expectancy line precedes survival line in the source); FAQ 3's opening restates the body's survival and life-expectancy claims. BTO gives the figure as '2 years' for a bird reaching breeding age; the page states it as two years rather than two further years.
The page saysweightKg: 0.039
The source saysAll adults 39.1±3.5 g (34.5-45.5 g, N=554)Note: task #635; Micro class

Source
03

Royal Society for the Protection of Birds

Kingfisher. Royal Society for the Protection of Birds.

The page saysIts "blue" is not really there.
The source saysa Kingfisher's feathers contain no blue pigmentNote: blockquote lead-in; paraphrases RSPB's 'contain no blue pigment.'
The page saysPluck a feather from a kingfisher's back and you will find no blue pigment in it; the feather is really a dull brown
The source saysBut, believe it or not, a Kingfisher's feathers contain no blue pigment. They're actually a dull brown colour
The page saysCommon kingfishers live along clear, slow-moving rivers, canals and ponds from Britain and Ireland
The source saysYou can find them on most rivers, canals and lakes across the UK, apart from in northern Scotland. ... They particularly like places where the water is clear or slow flowing, so that they can easily spot their next meal.
The page saysClear, slow-flowing rivers, canals, streams and ponds across Europe, Asia and sub-Saharan Africa
The source saysThey particularly like places where the water is clear or slow flowing, so that they can easily spot their next meal.Note: range portion (Europe, Asia, sub-Saharan Africa) is the same ADW geographic-range quote used above; 'streams' from ADW's habitat line ('shores of lakes, ponds, streams, and in wetlands').

Source
04

Stavenga et al. 2011

Stavenga et al. (2011). Kingfisher feathers – colouration by pigments, spongy nanostructures and thin films. Journal of Experimental Biology.

The page saysThe blue and cyan you see come from spongy nanostructures inside the feather barbs, which scatter light differently depending on the angle, an effect called iridescence
The source saysThe cyan and blue barbs contain spongy nanostructures with slightly different dimensions, causing different reflectance spectra. ... the spongy barb structures create iridescence.Note: bridges two sentences of the abstract with ...; 'differently depending on the angle' is the abstract's 'angle-dependent light scattering.'
The page saysthe orange breast feathers get their colour from pigment granules
The source saysScanning electron microscopy showed that the orange barbs contain small pigment granules.Note: the abstract names the orange feathers as the pigmented ones; the page no longer says 'only.'
The page saysMove around the bird and its "blue" can shift shade, because you are looking at a structure, not a dye
The source saysThe extent of the angle-dependent light scattering increases with decreasing wavelength.Note: 'shifts shade with viewing angle' and 'structural, not a dye' describe the angle-dependent iridescence the abstract reports; rspb-kingfisher independently states the blue 'comes from the way the tiny structures in the feathers scatter the light.'

Source
05

Vilches, Miranda & Arizaga 2019

Vilches, Miranda & Arizaga (2019). Does the Common Kingfisher (Alcedo atthis) select the most energetic fish prey? Ornis Fennica.

The page saysIts diet is mostly small fish, including minnows
The source saysThe most consumed fish-prey was the Pyrenean Minnow, and the Ebro Barbel was the less consumed preyNote: confirms 'minnow' as a documented prey fish of the species, though this Iberian population's minnow is a different species from a British one (same common name, genus Phoxinus).

Source
06

The IUCN Red List of Threatened Species 2024

Alcedo atthis. The IUCN Red List of Threatened Species 2024: e.T22683027A264589271.

The page saysthe IUCN rates the species Least Concern worldwide
The source saysIUCN Red List category: Least Concern (LC).

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.