AnimalTracks.wiki

What the sources say

Gentoo PenguinPygoscelis papua

Every figure, record and mechanism on the Gentoo Penguin profile was written from a source, and this is the working table behind it: 59 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.

Profile updated

Source
01

Animal Diversity Web, University of Michigan

Pygoscelis papua (gentoo penguin). Animal Diversity Web, University of Michigan.

The page saysThe Animal Diversity Web ranks the gentoo penguin (*Pygoscelis papua*) third largest of 17 penguin species
The source saysOf the 17 penguin species, gentoo penguins are the third largest in size.Note: attributed to ADW: the species count is ADW's and varies with taxonomy
The page saysAn adult stands about 76 centimetres tall
The source saysThey stand roughly at 76 centimeters when they reach adulthood.
The page saysweighs 4.5 to 8.5 kilograms, depending on the time of year
The source saysDepending on the time of the year, they can weigh anywhere from 4.5 to 8.5 kilograms.
The page saysIt is found only in the Southern Hemisphere, between 45 and 65 degrees south
The source saysare exclusively found in the Southern Hemisphere between 45 and 65 degrees south latitudeNote: 'only' paraphrases 'exclusively'
The page sayson the Antarctic Peninsula and many sub-Antarctic islands
The source saysgentoos are found on the Antarctic Peninsula as well as many sub-Antarctic islands
The page saysusually along the shoreline
The source saysGentoo penguins typically are found along the shoreline.
The page saysGentoos mainly eat fish, crustaceans and cephalopods
The source saysGentoo penguins are carnivores and mainly consume fish, crustaceans, and cephalopods.
The page saysthe mix changes with the time of year
The source saysDifferent times of the year mark different percentages of their diet.
The page saysKrill and shrimp make up most of the crustaceans
The source saysKrill ( Euphausia vallentini ) and shrimp ( Nauticaris marioni ) make up most of the crustacean diet.
The page saysthe cephalopods are mainly octopus and sometimes small squid
The source saysThe main types of cephalopods foraged on are octopi and sometimes small squid.
The page saysThe bright dark-orange to red spot on each side of the gentoo's partly black bill is attributed to carotenoid pigments from the krill it eats
The source saysThe beak of a gentoo is partially black but has a bright dark-orange to red spot on either side. The color of the spot is attributed to the carotenoids absorbed from the krill they eat.
The page saysYoung chicks face a much greater risk of predation than adults
The source saysYoung chicks are at much greater risk of predation than adults.
The page saysBrown skuas, the main predators of penguin chicks, mostly take chicks and eggs from the edge of a colony
The source saysBrown skuas ( Catharacta lonnbergi ) are the main predators of penguin chicks. Skuas mainly feed on the chicks and eggs found along the edge of the population
The page saysare less likely to attack chicks gathered in crèches, where one chick is hard to pick out of the group
The source saysSkuas are less likely to attack the crèches of gentoo chicks because it is hard to distinguish where one chick is within a group.
The page saysLeopard seals travel through the breeding grounds and attack penguins leaving and returning to the colony
The source saysLeopard seals ( Hydrurga leptonyx ) will travel in the gentoo breeding grounds and attack penguins leaving and returning to the colony.
The page saysA medium-sized gentoo nest can hold more than 1,700 pebbles
The source saysMedium-sized nests can contain over 1,700 pebbles.
The page saysshaped into a bowl with a wide rim and a hollow centre
The source saysThe nest is bowl shaped with a wide edge and a hollow center.
The page saysBoth parents build the nest
The source saysBoth parents are involved in nest-building.
The page saysfrom small stones found around the nesting site, including stones stolen from other nests
The source saysNests are made from small stones found around the nesting site, including stones stolen from other nests.
The page saysWhen one partner returns with a stone, the other bows repeatedly to accept it
The source sayswhen one returns to the breeding ground with a stone to use for the nest, the other will bow repeatedly to accept the stone
The page saysa display that likely helps strengthen the pair bond
The source saysThese displays likely serve to strengthen the pair bond.
The page sayswhose nest can hold over 1,700 pebbles
The source saysMedium-sized nests can contain over 1,700 pebbles.Note: tagline
The page saysShorelines of the Antarctic Peninsula and many sub-Antarctic islands
The source saysgentoos are found on the Antarctic Peninsula as well as many sub-Antarctic islands ... Gentoo penguins typically are found along the shoreline.Note: stats.habitat
The page sayswhere small pebbles for nests are plentiful
The source saysThe main feature of gentoo habitats is the prevalence of small pebbles, typically under 5 centimeters in diameter.Note: stats.habitat
The page saysFish such as rockcod and icefish, crustaceans such as krill and shrimp, and cephalopods, mostly octopus and sometimes small squid
The source saysmainly consume fish, crustaceans, and cephalopods ... Krill ( Euphausia vallentini ) and shrimp ( Nauticaris marioni ) make up most of the crustacean diet ... rockcod ( Notothenia squamifrons ) make up 90% of their diet, but they also consume unicorn icefish ( Channichthys rhinoceratus ) ... The main types of cephalopods foraged on are octopi and sometimes small squid.Note: stats.diet
The page saysMolting takes a lot of energy, and while it lasts they can't forage at sea
The source saysMolting is an energy intensive event ... During this time, P. papau cannot make forages out to sea and must fast
The page saysFor about 55 days beforehand, a gentoo makes frequent foraging trips and gorges to build up fat reserves, reaching its maximum weight of the year
The source saysThey make frequent trips and rapidly gain weight to reach maximum mass at this point of the year. Molting is an energy intensive event, and penguins must gorge themselves to build up fat reserves. This pre-molt period lasts for around 55 days.
The page saysThe molt itself lasts around 25 days, and the penguin fasts through it, losing about 200 grams a day
The source saysThe actual molting stage lasts 25 days. During this time, P. papau cannot make forages out to sea and must fast, losing about 200 grams a day.
The page saysIn the water, easily
The source saysgentoo penguins see excellently underwater, although they are impaired when on land
The page saysTheir retinas are very sensitive to the greens, blues and purples seen underwater, where they see excellently
The source saysgentoo penguins see excellently underwater ... Their retinas are very sensitive to the colors seen underwater such as green, blue, and purple.
The page saystheir vision is impaired on land and once they reach the surface
The source saysthey are impaired when on land ... this vision becomes impaired once they reach the surface of the water.
The page saysA gentoo egg is spherical and greenish-white and weighs about 125 grams on average
The source saysThe eggs are spherical and greenish-white ... on average egg weight is 125 grams.
The page saysIncubation takes about 35 days
The source saysThe eggs are incubated for an average of 35 days before hatching.
The page saysthe chick that hatches out weighs around 96 grams
The source saysThe chicks are frail and weigh about 96 grams.
The page saystags: antarctic
The source saysWithin this range, gentoos are found on the Antarctic Peninsula as well as many sub-Antarctic islands.
The page sayswhen one partner returns to the nest with a stone, the other bows repeatedly to accept it
The source sayswhen one returns to the breeding ground with a stone to use for the nest, the other will bow repeatedly to accept the stone

Source
02

AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources

AnAge entry for Pygoscelis papua. AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.

The page saysThe longest-lived gentoo in the AnAge longevity database is Olde, a female at Denmark's Odense Zoo, who reached 41 in captivity
The source saysMaximum longevity 41 years (captivity) ... The oldest penguin on record is "Olde" from the Odense Zoo that has lived for 41 yearsNote: female and Danish from the cited reference's title, '41-year-old penguin from Danish zoo breaks record with her extraordinary age'; scoped to the AnAge database (Build 15, 2023) rather than stated as a current record
The page saysweightKg: 5.95
The source saysAdult weight 5,950 gNote: ADW's range is 4.5 to 8.5 kg; both are Light (under 10 kg)

Source
03

The IUCN Red List of Threatened Species 2020

Pygoscelis papua. The IUCN Red List of Threatened Species 2020: e.T22697755A157664581.

The page saysThe IUCN's 2020 Red List assessment covers them all as one species, *Pygoscelis papua*
The source saysPygoscelis papua (Forster, 1781), IUCN taxon 22697755.Note: dated to the 2020 assessment the page cites, not a claim about current taxonomy
The page saysand lists it as Least Concern
The source saysIUCN Red List category: Least Concern (LC).Note: read through GBIF's copy of the Red List

Source
04

Tyler et al. 2020

Tyler et al. (2020). Morphometric and genetic evidence for four species of gentoo penguin. Ecology and Evolution.

The page saysA 2020 study of gentoos' genes and body measurements proposed splitting them into four species, one each in the Falkland Islands, South Georgia, the Kerguelen Islands, and the South Shetland Islands and western Antarctic Peninsula
The source saysWe suggest the designation of four species of gentoo penguin: P. papua in the Falkland Islands, P. ellsworthi in the South Shetland Islands/Western Antarctic Peninsula, P. taeniata in Iles Kerguelen, and a new gentoo species P. poncetii, described herein, in South Georgia.Note: 'proposed' keeps the paper's 'suggest'; 2020 is the reference's year (Ecology and Evolution vol. 10, December 2020); the title is 'Morphometric and genetic evidence'
The page saysOne Species or Four?
The source saysWe suggest the designation of four species of gentoo penguinNote: heading; a question, keeping the split as a proposal
The page sayswhich one 2020 study proposes splitting into four species
The source saysWe suggest the designation of four species of gentoo penguinNote: tagline
The page saysNot according to the study that proposed the split
The source saysparticularly P. taeniata and P. poncetii, which both show evidence of decline
The page saysIt flagged two of the four, the Kerguelen and South Georgia populations, as showing evidence of decline
The source saysP. taeniata in Iles Kerguelen, and a new gentoo species P. poncetii, described herein, in South Georgia ... We recommend reassessment by the IUCN of each species, particularly P. taeniata and P. poncetii, which both show evidence of decline.Note: the four are the proposed species; P. taeniata = Kerguelen, P. poncetii = South Georgia per the same paper
The page saysrecommended that the IUCN reassess each species
The source saysWe recommend reassessment by the IUCN of each species

Source
05

Clucas et al. 2014

Clucas et al. (2014). A reversal of fortunes: climate change 'winners' and 'losers' in Antarctic Peninsula penguins. Scientific Reports.

The page saysA 2014 study reported that gentoos of the southern subspecies were expanding their range southward with current warming, as they had during the warming after the last ice age
The source saysSouthern ( Pygoscelis papua ellsworthii ) gentoo sub-species ... Southern gentoo penguins are responding to current warming as they did during post-LGM warming, expanding their range southwards.Note: 'the last ice age' paraphrases the Last Glacial Maximum (LGM)
The page saysAdélie and chinstrap penguins had also expanded after the ice age, but were now declining on the Antarctic Peninsula
The source saysAll three pygoscelid penguins responded positively to post-LGM warming by expanding from glacial refugia ... Adélie and chinstrap penguins are experiencing a 'reversal of fortunes' as they are now declining in the Antarctic PeninsulaNote: past tense, dated to the 2014 study
The page saysThe authors called gentoos climate change "winners" and the other two "losers"
The source saysfavoring generalist gentoo penguins as climate change 'winners', while Adélie and chinstrap penguins have become climate change 'losers'.

Source
06

Williams et al. 1992

Williams et al. (1992). Diving pattern and performance in relation to foraging ecology in the gentoo penguin, Pygoscelis papua. Journal of Zoology.

The page saysIn a 1992 study that fitted depth recorders to nine gentoos
The source saysobtained using time-depth recorders ( n = 9 birds, 99 foraging trips)Note: abstract only; scope kept to the study's nine birds
The page saysforaging trips averaged 6 hours while the parents were brooding chicks and 10 hours in the later crèche period
The source saysForaging trip duration was 6 h and 10 h, and trip frequency 1.0/day and 0.96/day, during the brooding and creche periods, respectively.Note: 'later' from the same abstract: 'Foraging trip duration increased by 4 h between the brood and creche periods'
The page saysthe birds spent on average 52% of each trip diving
The source saysBirds spent on average 52%of each foraging trip diving.
The page saysTheir dives were strongly bimodal
The source saysDive depth and duration were highly bimodal
The page saysShallow dives, under 21 metres, averaged 4 metres and about 14 seconds
The source saysshallow dives (< 21 m) averaged 4 m and 0.23 minNote: 0.23 min x 60 = 13.8 s
The page saysDeep dives, past 30 metres, averaged 80 metres and 2.5 minutes
The source saysdeep dives (> 30 m) 80 m and 2.5 min
The page saysran deeper at midday, averaging 80 to 90 metres, than at dawn and dusk, when they averaged 40 metres
The source saysDeep dives showed clear diel patterns averaging 40 m at dawn and dusk and 80–90 m at midday.
The page saysThe authors suggest most shallow dives are for searching and most deep dives are for feeding
The source saysWe suggest that most shallow dives are searching/exploratory dives and most deep dives are feeding dives.
The page saysA penguin whose tracked deep dives averaged 80 metres
The source saysdeep dives (> 30 m) 80 m and 2.5 minNote: tagline
The page saysBimodal diving: in one tracking study, shallow dives averaged 4 metres and deep dives 80 metres
The source saysDive depth and duration were highly bimodal: shallow dives (< 21 m) averaged 4 m and 0.23 min, and deep dives (> 30 m) 80 m and 2.5 minNote: stats.superpower

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.