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What the sources say

Marine IguanaAmblyrhynchus cristatus

Every figure, record and mechanism on the Marine Iguana profile was written from a source, and this is the working table behind it: 42 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

Galapagos Conservation Trust

Marine iguana. Galapagos Conservation Trust.

The page saysOn average they measure about 0.7 meters and weigh 1.5 kilograms
The source saysAverage size: 0.7 metres ... Average weight: 1.5 kilograms
The page saysthey typically live 5 to 12 years
The source saysAverage lifespan: 5 - 12 years
The page saysusing sharp claws to hold the rock
The source saysuse their powerful claws to grip on to rocks in strong currents to feed
The page saysand it comes loaded with salt
The source saysDue to the high concentration of salt in their diet
The page saysfilter it out of the blood, and the iguana sneezes the excess away, often leaving salt crystals on its snout
The source saysmarine iguanas filter their blood at the nose and sneeze out the excess salt, often forming salt crystals on the snout
The page saysEntering the water also slows its heartbeat to half its normal pace, saving energy so it can feed for as long as possible.
The source saysUpon entering the water, their heartbeat slows to half its normal pace in order to conserve energy and allow them to feed for as long as possible
The page saysSkeletal shrinkage of up to 20% during El Niño food shortages, and nasal glands that expel excess salt
The source saysshrinking their skeleton by up to 20% to reduce their need for food
The page saysTo cope with El Niño, marine iguanas can shrink their own skeleton by up to 20 percent, cutting how much food they need.
The source saysadaptations to deal with the effects of the El Niño climate phenomenon, including shrinking their skeleton by up to 20% to reduce their need for food
The page saysthey have cut marine iguana populations by up to 85 percent
The source saysEl Niño periodically decreases the iguana population (by up to 85%)
The page saysTheir diet is so salty that they filter the salt from their blood at the nose and sneeze it out, often leaving crystals on the snout.
The source saysDue to the high concentration of salt in their diet, marine iguanas filter their blood at the nose and sneeze out the excess salt, often forming salt crystals on the snout
The page saysDuring El Niño its skeleton can shrink by as much as a fifth, lowering its need for food
The source saysadaptations to deal with the effects of the El Niño climate phenomenon, including shrinking their skeleton by up to 20% to reduce their need for foodNote: "a fifth" is 20% ("up to 20%")
The page saysweightKg: 1.5
The source saysAverage weight: 1.5 kilogramsNote: battleStats (settle #880)
The page saysEntering the water slows its heartbeat to half its normal pace, saving energy so it can feed for longer
The source saysUpon entering the water, their heartbeat slows to half its normal pace in order to conserve energy and allow them to feed for as long as possibleNote: vibe.reason (settle #880)

Source
02

Oceana

Marine Iguana. Oceana.

The page saysThe only lizard in the world that forages in the ocean, grazing algae underwater and sneezing out the salt.
The source saysThe marine iguana is the only lizard in the world that forages in the ocean
The page saysThe Only Lizard That Forages at Sea
The source saysThe marine iguana is the only lizard in the world that forages in the ocean
The page saysthe marine iguana (Amblyrhynchus cristatus) is the only lizard on Earth that forages in the ocean
The source saysThe marine iguana is the only lizard in the world that forages in the ocean
The page saysLarger iguanas dive up to 30 meters (98 feet) to reach algae beds beneath the waves, using sharp claws to hold the rock and a flattened tail to swim, while smaller animals stay close to shore and graze algae exposed at low tide.
The source sayssmaller individuals grazing on exposed algae between tides while larger iguanas dive up to 30 meters (98 feet) deep to reach algal beds beneath the waves
The page saysand a flattened tail to swim
The source sayssharp claws benefit their ability to graze underwater, while their flattened tail helps them swim through the waves
The page saysMarine algae grazed from submerged volcanic rock, reached by diving or exposed at low tide
The source sayssmaller individuals grazing on exposed algae between tides while larger iguanas dive up to 30 meters (98 feet) deep to reach algal beds beneath the waves
The page saysSpecialized glands in the nose filter it out of the blood
The source saysthe ability to excrete salt consumed from seawater through specialized glands in their noses
The page saysEl Niño events warm the ocean and reduce algal growth, which can bring food shortages and mass die-offs
The source saysEl Niño events, which warm ocean waters and reduce algal growth, can lead to food shortages and mass die-offs
The page saysEven so, larger iguanas dive as deep as 30 meters (98 feet) for algae, while smaller ones graze what low tide leaves exposed.
The source sayssmaller individuals grazing on exposed algae between tides while larger iguanas dive up to 30 meters (98 feet) deep to reach algal beds beneath the wavesNote: "as deep as" keeps "up to"

Source
03

Animal Diversity Web, University of Michigan

Amblyrhynchus cristatus (Marine Iguana). Animal Diversity Web, University of Michigan.

The page saysMarine algae is almost the only thing on the menu
The source saysThe marine iguana feed almost exclusively on marine algae
The page saysnasal glands that expel excess salt
The source saysexcretes concentrated salt crystals from a nasal glandNote: stats.superpower
The page saysRocky shorelines, low rock ledges and intertidal flats of the volcanic Galápagos Islands
The source saysfound on the volcanic islands of the Galapagos. Many of the islands have steep rock cliffs, low rock ledges and intertidal flatsNote: this is stats.habitat; "rocky shorelines" paraphrases "steep rock cliffs" and GCT's "coastal regions"

Source
04

Wikelski & Trillmich 1997

Wikelski & Trillmich (1997). BODY SIZE AND SEXUAL SIZE DIMORPHISM IN MARINE IGUANAS FLUCTUATE AS A RESULT OF OPPOSING NATURAL AND SEXUAL SELECTION: AN ISLAND COMPARISON. Evolution.

The page saysSize swings wildly between islands.
The source sayspopulations in the Galápagos exhibit 10-fold differences in body mass between island populations
The page saysA study comparing two of them found the heaviest males on Genovesa weighed about 900 grams, while those on Santa Fé reached 3,500 grams
The source saystwo island populations (max. male mass 900 g in Genovesa, 3500 g in Santa Fé)Note: "heaviest" paraphrases "max. male mass"; scoped to the paper's two-island comparison
The page saysMales are roughly twice as heavy as females.
The source saysmales being about twice as heavy as females

Source
05

Romero & Wikelski 2010

Romero & Wikelski (2010). Stress physiology as a predictor of survival in Galapagos marine iguanas. Proceedings of the Royal Society B: Biological Sciences.

The page saysOne study measured 98 adult males, then waited: months later a weak El Niño struck and 23 of them died.
The source sayswe captured 98 adult male marine iguanas ... Several months after collecting initial measurements, weak El Niño conditions affected the Galápagos and 23 iguanas died
The page saysThe dead and the survivors had not differed in how strongly they reacted to stress.
The source saysWe found no prior differences between dead and alive iguanas in baseline corticosterone concentrations, responses to acute stressors, nor in capacity to respond
The page saysThe dead had been worse at switching the stress hormone back off, which suggests that ending a stress response quickly helps an iguana survive starvation.
The source saysThe dead iguanas were typified by a reduced efficacy of negative feedback (i.e. poorer post-stress suppression of corticosterone release) compared with surviving iguanas ... These data suggest that a greater ability to terminate a stress response conferred a survival advantage during starvationNote: "quickly" is a paraphrase of "greater ability to terminate"; hedge "suggest" kept

Source
06

Trillmich 1983

Trillmich (1983). The Mating System of the Marine Iguana (Amblyrhynchus cristatus). Zeitschrift für Tierpsychologie.

The page saysOn Caamaño islet, where a study followed one breeding colony, females were ready to mate during only 24 days in January.
The source sayswas studied on Caamaño islet ... The mating readiness of females was well synchronized to only 24 days in Jan.
The page saysTerritorial males cut back their foraging and fasted for a median of 12 days that month, losing up to 26 percent of their body weight.
The source saysmales shortened their foraging time and even fasted for some time in Jan. (median fast duration 12 days). They lost up to 26% body weight during this period

Source
07

Vitousek et al. 2007

Vitousek et al. (2007). Heterospecific alarm call recognition in a non-vocal reptile. Biology Letters.

The page saysMarine iguanas have no voice of their own, yet they can eavesdrop on the alarm call of the Galápagos mockingbird and respond with anti-predator behavior.
The source saysa non-vocal reptile, the Galápagos marine iguana ( Amblyrhynchus cristatus ), can eavesdrop on the alarm call of the Galápagos mockingbird ( Nesomimus parvulus ) and respond with anti-predator behaviour
The page saysBefore a 2007 study showed this, the trick had been described only in animals that make calls themselves.
The source saysThe ability to recognize and respond to the alarm calls of heterospecifics has previously been described only in species with vocal communicationNote: 2007 is the study's publication year (reference heterospecific-2007, Biology Letters 2007); "before" paraphrases "previously"
The page saysNot in their own voices: they are non-vocal. Instead they tune in to a bird, and the Galápagos mockingbird's warning call puts them on guard against predators.
The source saysa non-vocal reptile, the Galápagos marine iguana ( Amblyrhynchus cristatus ), can eavesdrop on the alarm call of the Galápagos mockingbird ( Nesomimus parvulus ) and respond with anti-predator behaviour

Source
08

Thompson 2015

Thompson (2015). “Only the Amblyrhynchus”: Maria Graham’s Scientific Editing of Voyage of HMS Blonde (1826/27). Journal of Literature and Science.

The page saysHMS Blonde called at the islands
The source saysthe Blonde had visited the Galapagos Islands
The page sayson its 1824-25 voyage
The source saysthe 1824-25 voyage of HMS BlondeNote: the paper dates the voyage 1824-25 and says the Blonde visited the Galapagos; it gives no year for the Galapagos call, so the page gives none
The page saysthe published account of the trip, edited by Maria Graham
The source saysMaria Graham, who in 1826 was commissioned by the publisher John Murray to produce an account of a recent naval expeditionNote: the quoted words are in the published narrative Graham produced; the paper thinks she likely coined the phrase from Dampier's journal (note 9 allows the chaplain Bloxam as source), so the page attributes it to the published account only
The page saysdescribed the iguanas sitting on the black lava rocks "like so many imps of darkness."
The source sayssat on the black lava rocks like so many imps of darknessNote: the quoted words are in the published narrative Graham produced; the paper thinks she likely coined the phrase from Dampier's journal (note 9 allows the chaplain Bloxam as source), so the page attributes it to the published account only

Source
09

MacLeod, Nelson & Grant 2020

MacLeod, Nelson & Grant (2020). Amblyrhynchus cristatus. The IUCN Red List of Threatened Species 2020: e.T1086A177552193.

The page saysVulnerable
The source saysIUCN Red List category: Vulnerable (VU).Note: category read through GBIF's copy of the Red List, checked against IUCN taxon 1086; this is stats.conservationStatus

Source
10

Lewbart et al. 2015

Lewbart et al. (2015). Blood gases, biochemistry and haematology of Galápagos marine iguanas (Amblyrhynchus cristatus). Conservation Physiology.

The page saysOn San Cristóbal, 35 iguanas measured from nose to tail tip ran 72.5 to 121 centimeters
The source saysA total of 35 marine iguanas (24 males, four females and seven immature) were sampled from three locations on San Cristobal Island. The mean SVL for the entire group was 40.5 cm (28.5–51.0 cm) and the mean TL (tip of nose to tip of tail) was 98.1 cm (72.5–121.0 cm)Note: replaces GCT's 'Maximum size: 1.5 metres', which no primary total-length measure supports (settle #940)

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.