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What the sources say

Grey HeronArdea cinerea

Every figure, record and mechanism on the Grey Heron profile was written from a source, and this is the working table behind it: 45 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

Ardea cinerea (grey heron). Animal Diversity Web, University of Michigan.

The page saysA fish-eater that usually hunts by standing still, then generally swallows its catch whole.
The source saysGrey herons feed on a wide range of prey items but are primarily piscivores.Note: tagline; rest below
The page saysusually hunts by standing still
The source saysUsually these herons stand still and wait for prey to approach in the water.
The page saysgenerally swallows its catch whole
The source saysThey capture prey with their bills and generally swallow it whole, in one swift gulping action.
The page saysShallow water across Eurasia and Africa, from rivers and lakes to marshes and estuaries
The source saysThese bodies of water may include saltwater or brackish inlets and estuaries, freshwater rivers, streams, lakes, or marshesNote: stats.habitat; the source says 'may include'
The page saysMostly fish, plus insects, crustaceans, frogs and small mammals
The source saysIn addition to fish (Class Actinopterygii), their diet consists of insects (Class Insecta), crustaceans (Subphylum Crustacea), frogs (Class Amphibia) and small mammals.Note: stats.diet
The page saysTypically waits for prey to come within striking range, then generally swallows it whole
The source saysHunting behaviors typically involve waiting for prey until they are within striking range.Note: stats.superpower
The page saysTypically waits for prey to come within striking range, then generally swallows it whole
The source saysgenerally swallow it whole, in one swift gulping actionNote: stats.superpower
The page sayswades through shallow water or walks on land
The source saysTo locate food, grey herons wade through shallow water or move on land.
The page saystypically waits for prey to come within striking range
The source saysHunting behaviors typically involve waiting for prey until they are within striking range.
The page saysFish are the main course, which makes it a piscivore
The source saysGrey herons feed on a wide range of prey items but are primarily piscivores.
The page saysInsects, crustaceans, frogs and small mammals count as food too, and it sometimes takes tiny birds.
The source saystheir diet consists of insects (Class Insecta), crustaceans (Subphylum Crustacea), frogs (Class Amphibia) and small mammals. They sometimes even ingest tiny birds.
The page saysThe biggest bird species a grey heron has been recorded trying to eat is the white-throated rail.
The source saysRecent studies have documented grey herons attempting to prey upon and consume white-throated rails (Dryomnas cuvieri aldabranus). This is the largest bird species upon which grey herons attempt to prey.
The page saysa heron pulls its head back toward its body and trails its legs behind it
The source saysgrey herons fly with their head pulled back toward the body while keeping their legs extended behind them
The page saysCranes fly with the neck extended, which sets the two apart.
The source saysThis body positioning during flight distinguishes herons from cranes (Family Gruidae), which fly with their neck extended.
The page saysGrey herons live across Eurasia and Africa
The source saysThey are found throughout Eurasia and Africa.
The page saysthat can include freshwater rivers, streams, lakes and marshes, saltwater or brackish inlets and estuaries, and even fish farms
The source saysThese bodies of water may include saltwater or brackish inlets and estuaries, freshwater rivers, streams, lakes, or marshes, and even aquacultures used in fish farming.
The page saysGrey herons are mostly solitary
The source saysWhile grey herons are generally solitary birds, they gather during the breeding season to improve their chances of finding a mate.
The page saysEggs typically take 25 to 26 days to hatch
The source saysEggs typically take 25 to 26 days to incubate and hatch.
The page saysthe chicks fledge (leave the nest) after about 50 days
The source saysHatchlings fledge after approximately 50 days.
The page saysHatchlings compete for food and commonly push one another out of the nest.
The source saysHatchlings compete with one another for food and parental care during early development, and commonly push one another from the nest.
The page saysWhen food runs short, the smallest or weakest chick is sometimes killed by its siblings.
The source saysSiblicide often occurs when food is in short supply. In these cases, nestlings show aggression toward one another, and sometimes the smallest or weakest offspring are killed.
The page saysAnimal Diversity Web gives a typical body length of 84 to 102 cm
The source saysBody length in grey herons typically ranges from 84 to 102 cm.Note: FAQ 1
The page saysMostly fish. Insects, crustaceans, frogs and small mammals are on the menu too, and it sometimes takes tiny birds.
The source saystheir diet consists of insects (Class Insecta), crustaceans (Subphylum Crustacea), frogs (Class Amphibia) and small mammals. They sometimes even ingest tiny birds.Note: FAQ 3
The page saysIt usually stands still in the water and waits for prey to approach.
The source saysUsually these herons stand still and wait for prey to approach in the water.Note: FAQ 3
The page saysBody length typically runs from 84 to 102 cm
The source saysBody length in grey herons typically ranges from 84 to 102 cm.
The page saysand the wingspan from 155 to 175 cm
The source sayswith a wingspan of 155 to 175 cm
The page sayswingspan of 155 to 175 cm
The source sayswith a wingspan of 155 to 175 cmNote: FAQ 1
The page saysWhere the water is deeper, the usual pose is on one leg, and the wait sometimes stretches on for a long time.
The source saysgrey herons in deeper water typically stand still on one foot and wait, sometimes for extended periods of time
The page saysTheir best hunting is thought to happen by moonlight.
The source saysThey are thought to be most successful in capturing prey in the moonlight.
The page saysA grey heron usually hunts by doing almost nothing.
The source saysUsually these herons stand still and wait for prey to approach in the water.
The page saysWhen one does, the heron seizes it with its bill, and the catch generally goes down whole in one quick gulp.
The source saysThey capture prey with their bills and generally swallow it whole, in one swift gulping action.
The page saysHow often it succeeds is not clear, but injuries have been noted after the attempts.
The source saysWhile it is not clear how often grey herons succeed in feeding on rails, injuries have been noted after feeding attempts.
The page saysthey need shallow water to fish in
The source saysGrey herons also require some type of shallow body of water, which they use as their primary forage sites.
The page saysA grey heron usually hunts by doing almost nothing, standing still until prey comes within striking range.
The source saysHunting behaviors typically involve waiting for prey until they are within striking range.Note: vibe.reason

Source
02

British Trust for Ornithology

BirdFacts: Grey Heron. British Trust for Ornithology.

The page saysBirdFacts, from the British Trust for Ornithology, gives a weight of 1.5 kg.
The source saysKey Stats Status Common Weight 1.5kgNote: BTO key stat, unqualified (not typical or maximum); preferred over ADW's 0.226 to 1.36 kg as the current institution page
The page sayscome together to nest in treetop colonies known as heronries. Some sites have stayed in use for many decades
The source saysGrey Herons gather to nest in treetop sites called heronries, some of which have been occupied for many decades.
The page saysthe UK has monitored them since 1928 through the Heronries Census
The source saysThese have been monitored in the UK since 1928 through the Heronries Census.
The page saysThe UK breeding population is rated stable from 1929 to 2024
The source saysPopulation Change Stable 1929 to 2024
The page says11 thousand pairs in 2013 to 2017
The source saysUK (breeding) 11 thousand pairs (2013–17)Note: year range 2013-17 in source; cached dash is mojibake
The page saystypically lives 5 years
The source saysTypical life expectancy of bird reaching breeding age 5 years with breeding typically at 2 years
The page saysJust 0.26 of juveniles, about a quarter, survive to age 2.
The source saysSurvival of juveniles All juveniles 0.26 (to age 2)Note: BTO survival is the proportion surviving, from ringing data
The page saysThe oldest ringed bird on BTO's record, set in 2003, reached 23 years, 9 months and 2 days.
The source saysMaximum age from a ringed bird 23 years, 9 months, 2 days (set in 2003)
The page saysBTO's ringing data put typical life expectancy at 5 years for a bird that reaches breeding age.
The source saysTypical life expectancy of bird reaching breeding age 5 years with breeding typically at 2 yearsNote: FAQ 2
The page saysThe oldest ringed bird on its record reached 23 years, 9 months and 2 days, a record set in 2003.
The source saysMaximum age from a ringed bird 23 years, 9 months, 2 days (set in 2003)Note: FAQ 2

Source
03

The IUCN Red List of Threatened Species 2021

Ardea cinerea. The IUCN Red List of Threatened Species 2021: e.T22696993A166317370.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: stats.conservationStatus

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.