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What the sources say

MallardAnas platyrhynchos

Every figure, record and mechanism on the Mallard 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

U.S. Fish and Wildlife Service

Mallard (Anas platyrhynchos). U.S. Fish and Wildlife Service.

The page saysAlmost any freshwater habitat
The source saysThis species is found in all flyways and in almost any freshwater habitat.Note: stats.habitat
The page saysa medium to large dabbling duck
The source saysMallards are a medium to large dabbling duck.
The page says50 to 65 cm long
The source saysLength: 19.7 to 25.6 in (50 to 65 cm)
The page sayswingspan of 82 to 95 cm
The source saysWingspan: 32.3 to 37.4 in (82 to 95 cm)
The page saysMales and hens are similar in size, and both weigh 0.9 to 1.4 kg
The source saysBoth sexes are similar in size ranging 2 to 3 pounds (.9 to 1.4 kilograms).Note: source prints .9 kg (2 lb); rendered 0.9
The page saysIn North America, most mallards are migratory, breeding in the northern United States and Canada and wintering in the southern United States and Mexico
The source saysmost individuals are migratory and breed in the northern United States and Canada and winter in the Southern United States and Mexico.
The page saysthe most abundant duck species in North America
The source saysis the most abundant duck species in North America.

Source
02

National Audubon Society, Guide to North American Birds

Mallard. National Audubon Society, Guide to North American Birds.

The page saysAlmost any freshwater habitat across the Northern Hemisphere, from marshes and rivers to city parks
The source saysMarshes, wooded swamps, grain fields, ponds, rivers, lakes, bays, city parks.Note: stats.habitat
The page saysMostly plants, plus insects, worms, mollusks and small fish
The source saysMajority of diet is plant material, including seeds, stems, and roots of a vast variety of different plants, especially sedges, grasses, pondweeds, smartweeds, many others; also acorns and other tree seeds, various kinds of waste grain. Also eat insects, crustaceans, mollusks, tadpoles, frogs, earthworms, small fish.Note: stats.diet
The page saysMallards forage in water by dabbling, by submerging the head and neck, or by up-ending
The source saysThe Mallard forages in water by dabbling, submerging head and neck, up-ending, rarely by diving
The page saysThey rarely dive
The source saysforages in water by dabbling, submerging head and neck, up-ending, rarely by diving
The page saysOn land they graze and pluck seeds
The source saysforages on land by grazing, plucking seeds, grubbing for roots.
The page saysThe majority of the diet is plant material, including seeds, stems and roots
The source saysMajority of diet is plant material, including seeds, stems, and roots of a vast variety of different plants
The page saysThey also eat insects, mollusks, tadpoles, frogs, earthworms and small fish
The source saysAlso eat insects, crustaceans, mollusks, tadpoles, frogs, earthworms, small fish.
The page saysThe hen leads the young within a day after hatching
The source saysThe female Mallard leads the young within a day after hatching.
The page saysin many places the mallard has managed to domesticate itself, relying on handouts in city parks
The source saysIn many places this species has managed to domesticate itself, relying on handouts in city parks.
The page saystags: urban
The source saysIn many places this species has managed to domesticate itself, relying on handouts in city parks.Note: task #1009; the habitat line already names city parks

Source
03

National Wildlife Federation, Wildlife Guide

Mallard. National Wildlife Federation, Wildlife Guide.

The page saysA mallard usually lives 5 to 10 years in the wild
The source saysA mallard usually lives for 5 to 10 years in the wild.Note: usually rendered as most
The page saysthe oldest known was a male that lived to 27
The source saysThe oldest known mallard was a male that lived to be 27 years old.
The page saysUsually 5 to 10 years in the wild, according to the National Wildlife Federation
The source saysA mallard usually lives for 5 to 10 years in the wild.
The page sayswhose oldest known mallard was a male aged 27
The source saysThe oldest known mallard was a male that lived to be 27 years old.

Source
04

Rogers 2001

Rogers (2001). Anas platyrhynchos (mallard). Animal Diversity Web, University of Michigan.

The page saysThe familiar quack comes from the female
The source saysThe familiar "quack" of ducks is from the female mallard
The page saysHer decrescendo call is given when she wants to bring other ducks, such as her ducklings, to her
The source saysit is named the "decrescendo call", and can be heard for miles. A female will give the call when she wants to bring other ducks to her, such as her ducklings

Source
05

Cunningham & Russell 2000

Cunningham & Russell (2000). Egg investment is influenced by male attractiveness in the mallard. Nature.

The page saysa hen that lays larger eggs after mating with a male she prefers
The source sayslay larger eggs after copulating with preferred malesNote: tagline; copulating rendered as mating
The page saysHens lay larger eggs after mating with a preferred male
The source sayslay larger eggs after copulating with preferred malesNote: stats.superpower
The page saysA hen mallard's eggs can depend on her mate
The source saysindividual female mallard (Anas platyrhynchos) lay larger eggs after copulating with preferred males and smaller eggs after copulating with less preferred males. As a result, females produced offspring of better body condition when paired with preferred males.
The page saysindividual females laid larger eggs after copulating with preferred males and smaller eggs after copulating with less preferred males
The source saysindividual female mallard (Anas platyrhynchos) lay larger eggs after copulating with preferred males and smaller eggs after copulating with less preferred males. As a result, females produced offspring of better body condition when paired with preferred males.
The page saysthey produced offspring in better body condition when paired with preferred males
The source saysindividual female mallard (Anas platyrhynchos) lay larger eggs after copulating with preferred males and smaller eggs after copulating with less preferred males. As a result, females produced offspring of better body condition when paired with preferred males.

Source
06

Schummer et al. 2023

Schummer et al. (2023). Population genetics and geographic origins of mallards harvested in northwestern Ohio. PLOS ONE.

The page saysThe wild ancestor of nearly all domestic ducks
The source saysNearly all domestic ducks (e.g., Pekin duck) are decedents of wild, Eurasian mallardsNote: tagline
The page saysNearly all domestic ducks, such as the Pekin duck, descend from wild Eurasian mallards
The source saysNearly all domestic ducks (e.g., Pekin duck) are decedents of wild, Eurasian mallardsNote: source spells descendants 'decedents'
The page saysdomesticated in China around 500 B.C.
The source saystheir domestication in China around 500 B. C.
The page saysGame-farm mallards are released into the wild on purpose
The source saysthe intentional release of the game-farm mallard breed
The page saysthe spread of their genes into wild populations has been hypothesized to at least partly explain recent mallard declines in eastern North America
The source saysIncreasing prevalence of game-farm genes within wild populations is predicted to decrease mallard fitness because of introduction of artificially selected, maladaptive traits [ 17 , 19 ], and this has been hypothesized to at least partially explain recent mallard population declines in eastern North America

Source
07

Kraus et al. 2011

Kraus et al. (2011). Evolution and connectivity in the world-wide migration system of the mallard: Inferences from mitochondrial DNA. BMC Genetics.

The page saysacross the Northern Hemisphere
The source saysdistributed widely over the whole Northern HemisphereNote: stats.habitat
The page saysIt is the most numerous Holarctic waterfowl species, found across the whole Northern Hemisphere
The source saysThe mallard ( Anas platyrhynchos ) is the most numerous Holarctic waterfowl species and distributed widely over the whole Northern Hemisphere.
The page saysMallards that breed far north mostly migrate and spend winter much farther south
The source saysNortherly breeding birds are mostly migratory, wintering much further south
The page saysThose that breed in temperate regions, such as parts of Western Europe, can be residents
The source saysbirds breeding in temperate regions, especially in parts of Western Europe, can be residentNote: resident, as the source words it
The page saystags: migratory
The source saysMigratory mallard populations often do not exhibit clearly defined routes, even when breeding and non-breeding destinations are thousands of kilometres distantNote: task #1009; the definition asks for seasonal journeys of thousands of kilometres. The same paragraph: 'Northerly breeding birds are mostly migratory, wintering much further south', so the tag is the species' northern populations, as the page's FAQ says

Source
08

Stanford Birds

Duck Displays. Stanford Birds.

The page saysGroups of four to five drakes may swim around a female, arch their necks and whistle
The source saysGroups of four to five males may swim around females, arching their necks, whistling
The page saysThen they dip their bills below the water and jerk them up to their breasts, spurting water toward the preferred female
The source sayslowering their bills below the water surface and jerking their bills up to their breasts while spurting water toward the preferred female (water-flick or grunt-whistle)
The page saysThis water-flick may take only a fraction of a second
The source saysThe water-flick may take only a fraction of a second to complete.
The page saysLike other dabbling ducks of the genus Anas, a mallard can spring into the air without running across the water first
The source saysdabbling or "puddle" ducks (in North America members of the genus Anas -- who are able to spring into the air without running across the water surface)
The page saysGroups of four to five mallard drakes may swim around one female
The source saysGroups of four to five males may swim around females, arching their necks, whistlingNote: vibe.reason; same quote as the body claim "Groups of four to five drakes may swim around a female, arch"

Source
09

The IUCN Red List of Threatened Species 2025

Anas platyrhynchos. The IUCN Red List of Threatened Species 2025: e.T22680186A281835571.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: stats.conservationStatus
The page saysThe IUCN Red List rates the mallard Least Concern
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.