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What the sources say

European Herring GullLarus argentatus

Every figure, record and mechanism on the European Herring Gull profile was written from a source, and this is the working table behind it: 63 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

RSPB

Herring Gull. RSPB.

The page saysA large, pink-legged gull
The source saysHerring Gulls are large, noisy gullsNote: tagline; legs: next claim
The page sayspink-legged
The source saysTheir legs are pink with webbed feetNote: tagline
The page sayspaddles its feet on the ground to bring worms up
The source saysYou might see them imitating rain with their feet as they encourage worms to the surface.Note: tagline
The page saysand now nests on rooftops as well as cliffs
The source saysThey tend to nest on the ground, on cliff ledges, or on rooftopsNote: tagline
The page saysPaddling for worms
The source saysYou might see them imitating rain with their feet as they encourage worms to the surface.Note: heading
The page saysThe RSPB says you might see gulls imitating rain with their feet to encourage worms to the surface.
The source saysYou might see them imitating rain with their feet as they encourage worms to the surface.
The page saysThe RSPB gives its length as 54 to 60 centimetres.
The source saysMeasuring between 54 and 60cm
The page saysAdults have light grey backs, white undersides and black wing tips with white spots.
The source saysAdults have light grey backs, white under parts, and black wing tips with white 'mirrors'.Note: spots: RSPB key features also say black wingtips have white spots
The page saysTheir legs are pink.
The source saysTheir legs are pink with webbed feet
The page saysThe heavy bill has a red spot
The source saysheavy, slightly curved bills marked with a red spot
The page sayschicks peck at it to tell the parent they are hungry.
The source saysHerring Gull chicks will peck at the red spot on their parent's beak to let them know they are hungry.
The page saysFrom cliffs to rooftops
The source saysHerring Gulls began swapping cliffside ledges for urban rooftops in the 1920sNote: heading
The page saysIn the 1920s they began swapping cliffside ledges for urban rooftops.
The source saysHerring Gulls began swapping cliffside ledges for urban rooftops in the 1920sNote: RSPB, UK scope; follows the 'In Britain' sentence
The page saysThe RSPB notes that pair bonds are often lifelong.
The source saystheir pair bonds are often lifelong
The page saysIn the UK the RSPB gives its conservation status as Red because of ongoing population declines.
The source saysThis species is on the Red List due to ongoing population declines and wintering population declines.Note: UK Birds of Conservation Concern Red List, not IUCN; page header 'UK Conservation status: Red'; 'because' paraphrases 'due to'
The page saysThis is a large gull.
The source saysHerring Gulls are large, noisy gulls
The page saysthe RSPB says you might see gulls imitating rain with their feet to encourage worms to the surface
The source saysYou might see them imitating rain with their feet as they encourage worms to the surface.Note: vibe.reason

Source
02

BTO BirdFacts, British Trust for Ornithology

Herring Gull. BTO BirdFacts, British Trust for Ornithology.

The page saysThe BTO says the green shore crab is a particular favourite.
The source sayswith Green Shore Crab being a particular favourite
The page saysSize and lifespan
The source saysTypical life expectancy of bird reaching breeding ageNote: heading
The page saysAdults weigh 970.6 grams on average
The source saysAll adults / 970.6±152.3 gNote: BTO biometrics: adult body weight average
The page saysnine in ten fall between 757 and 1,264 grams
The source says(757-1264 g, N=974)Note: 5th to 95th percentiles per BTO
The page saysA gull that reaches breeding age can expect to live about 12 years.
The source saysTypical life expectancy of bird reaching breeding age / 12 years with breeding typically at 4 years
The page saysBreeding usually starts at around 4 years old.
The source says12 years with breeding typically at 4 years
The page saysIn Britain, herring gulls were once confined to the coast as breeders.
The source saysOnce confined to the coast as a breeding birdNote: BTO BirdFacts is a British page ('one of our most familiar'); scope Britain
The page saysThe British Trust for Ornithology uses ringing data to estimate a typical life expectancy of 12 years for a gull that survives to breeding age.
The source saysSurvival is shown as the proportion of birds surviving from one year to the next and is derived from bird ringing data. / It can also be used to estimate how long birds typically live. / Lifespan / Typical life expectancy of bird reaching breeding age / 12 yearsNote: FAQ 1
The page saysAbout 88 in 100 adults survive from one year to the next.
The source saysSurvival of adults All adults 0.88Note: FAQ 1; 0.88 annual survival = 88 in 100
The page saysweightKg: 0.97
The source saysAll adults 970.6±152.3 gNote: battleStats.weightKg; BTO live-bird average, N=974

Source
03

BirdLife International Data Zone

European Herring Gull (Larus argentatus). BirdLife International Data Zone.

The page saysCoasts and near-coastal areas, and can forage inland on lakes, reservoirs, fields and refuse dumps
The source saysThe species inhabits coastal and near-coastal areas but may also forage inland on large lakes and reservoirs, fields and refuse dumpsNote: stats.habitat
The page saysbreeds from Iceland, the British Isles and France through northwest Europe and northern Siberia to the Bering Strait
The source saysHerring Gulls breed from Iceland, the British Isles and France through northwest Europe to northwest Russia, and northern Siberia east to the Bering StraitNote: stats.habitat
The page saysFish, earthworms, crabs and other marine invertebrates, bird eggs and young, rodents, insects, and scraps from refuse dumps
The source saysIt takes fish, earthworms, crabs and other marine invertebrates (e.g. molluscs, starfish or marine worms), adult birds, bird eggs and young, rodents, insects (e.g. ants), berries and tubers (e.g. turnips)Note: stats.diet; sentence also names adult birds, berries, tubers (left out of the stat for length)
The page saysscraps from refuse dumps
The source saysIt also scavenges at refuse dumps, fishing wharves and sewage outfall zonesNote: stats.diet
The page saysBirdLife International calls its diet highly opportunistic
The source saysThe species has a highly opportunistic diet
The page saysit takes fish, earthworms, crabs, other marine invertebrates, bird eggs and young, rodents and insects
The source saysIt takes fish, earthworms, crabs and other marine invertebrates (e.g. molluscs, starfish or marine worms), adult birds, bird eggs and young, rodents, insects (e.g. ants)
The page saysIt also scavenges at refuse dumps.
The source saysIt also scavenges at refuse dumps
The page saysThe gull breeds from Iceland, the British Isles and France through northwest Europe to northwest Russia, and across northern Siberia east to the Bering Strait.
The source saysHerring Gulls breed from Iceland, the British Isles and France through northwest Europe to northwest Russia, and northern Siberia east to the Bering Strait
The page saysNorthern birds migrate, while southern ones are nomadic or do not migrate.
The source saysNorthern breeding populations of this species are migratory (del Hoyo et al. 1996) whereas populations in the south are nomadic or completely non-migratory
The page saysA common bird in decline
The source saysCurrent population trend / DecreasingNote: heading
The page saysBirdLife estimates approximately 1,060,000 to 1,220,000 mature adults
The source saysapproximately 1,060,000-1,220,000 mature individuals
The page saysbut the population trend appears to be decreasing.
The source saysthe population trend appears to be decreasingNote: trend derivation 'Suspected'
The page saysThe decline appears to be partly linked to waste management and reduced fishery discards.
The source saysThe decline appears to be partly linked to waste management and reduced fishery discards
The page saysBirdLife International estimates 531,000 to 608,000 breeding pairs.
The source saysThe breeding population is estimated to number 531,000-608,000 pairsNote: FAQ 2
The page saysThe trend appears to be decreasing
The source saysthe population trend appears to be decreasingNote: FAQ 2
The page saysbut BirdLife does not currently believe the fall is fast enough to count as Vulnerable.
The source saysthe decline is not currently believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterionNote: FAQ 2
The page saysIts menu is long.
The source saysThe species has a highly opportunistic diet and will exploit almost any superabundant source of foodNote: framing sentence for the diet list
The page saysNumbers grew during the 20th century
The source saysThe species's population increased and the distribution expanded in many range states and overall during the 20th centuryNote: 'and overall' covers the whole population
The page saysaround the turn of the century declines began in several key countries, including Norway and the UK.
The source saysAround the turn of the century, declines began in several key countries, including Norway (Fauchald et al. 2015) and the UK (JNCC 2020)

Source
04

The IUCN Red List of Threatened Species 2021

Larus argentatus. The IUCN Red List of Threatened Species 2021: e.T62030608A206585142.

The page saysLeast Concern
The source saysLeast ConcernNote: stats.conservationStatus; Data Zone factsheet, year of last assessment 2021
The page saysThe IUCN Red List rated the species Least Concern in 2021.
The source saysYear of last assessment 2021 ... Least ConcernNote: BirdLife Data Zone factsheet, year of last assessment and category

Source
05

Catania 2008

Catania (2008). Worm Grunting, Fiddling, and Charming—Humans Unknowingly Mimic a Predator to Harvest Bait. PLoS ONE.

The page sayspaddles its feet on the ground to bring worms up
The source saysTinbergen [4] noted that herring gulls exhibit a foot-paddling behavior, which flushes worms from the ground in Europe.Note: tagline; second source
The page saysPaddles its feet on the ground to flush worms to the surface
The source saysherring gulls exhibit a foot-paddling behavior, which flushes worms from the ground in EuropeNote: stats.superpower
The page saysIt paddles its feet on the ground.
The source saysherring gulls exhibit a foot-paddling behavior, which flushes worms from the ground in Europe
The page saysA 2008 study of worm hunting quotes Tinbergen's view that paddling brings up earthworms, which seem to have an innate reaction to the quivering of the soil that helps them escape their arch enemy, the mole.
The source saysOne is the bringing up of earthworms , which seem to have an innate reaction to the quivering of the soil which is of value , enabling them to escape their arch enemy , the moleNote: blockquote; Catania quotes Tinbergen; 2008 is the reference's year
The page saysTinbergen also suggested paddling flushes small animals out of muddy pools of water
The source saysHe suggests the other reason was to flush and expose small animals in muddy pools of water, where foot paddling is often observed.
The page saysand the study suggests that is where the habit began.
The source saysThis presumably more common practice for gulls suggests the origins of the behavior
The page saysMole alarm
The source sayshe suggested the earthworm's innate response to vibrations was to escape molesNote: blockquote lead-in

Source
06

Goumas et al. 2019

Goumas et al. (2019). Herring gulls respond to human gaze direction. Biology Letters.

The page saysin towns they appear to have turned that habit on people.
The source saysHerring gulls in urban environments appear to have generalized their kleptoparasitic activities to target humans
The page saysIn Cornwall, researchers found that gulls that did touch a bag of chips took significantly longer to approach when the person was looking straight at them.
The source saysWhen gulls did touch the food, they took significantly longer to approach when the experimenter's gaze was directed towards them compared with directed away.Note: food was 250 g of fried potato chips in a sealed bag; 'coastal towns in Cornwall, UK'
The page saysResearchers in Cornwall set a sealed bag of chips in front of a person
The source saysThe food was presented inside a sealed, transparent freezer bagNote: FAQ 3; chips: 'We placed 250 g of fried potato chips'
The page saysonly 26% of the gulls they targeted would touch it
The source saysonly 26% of targeted gulls would touch the foodNote: FAQ 3
The page sayswhich suggests food-snatching is likely done by a minority.
The source sayssuggesting that food-snatching is likely to be conducted by a minority of individualsNote: FAQ 3
The page saysSome do.
The source sayssuggesting that food-snatching is likely to be conducted by a minority of individualsNote: FAQ 3
The page saysHerring gulls steal food from other gulls and other species
The source saysherring gulls are kleptoparasites [ 6 ] and take food from both conspecifics and heterospecificsNote: conspecifics = other herring gulls
The page saysIn Cornwall
The source saysWe studied herring gulls (hereafter ‘gulls’) in coastal towns in Cornwall, UKNote: also FAQ 3

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.