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What the sources say

Ross SealOmmatophoca rossii

Every figure, record and mechanism on the Ross Seal profile was written from a source, and this is the working table behind it: 43 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

Ommatophoca rossii. Animal Diversity Web, University of Michigan.

The page sayswith enormous eyes
The source saysdisproportionately large eyes (70mm in diameter)
The page sayshas disproportionately large eyes, 70 millimetres in diameter, which make it easy to distinguish from closely related seals
The source saysRoss seals can easily be distinguished from closely related seals by their disproportionately large eyes (70mm in diameter)
The page saysfemales average larger than males
The source saysMales average smaller than females
The page saysThey have a thick neck, a slender body and the shortest hair and whiskers of any true seal
The source sayswith a thick neck and a slender body. Members of this species have short body hairs, with the shortest hair and vibrissae of any phocidNote: phocid = true seal, vibrissae = whiskers
The page says70-millimetre eyes
The source saysdisproportionately large eyes (70mm in diameter)
The page saysThey measure 70 millimetres across, disproportionately large for the animal, and they make the species easy to tell apart from closely related seals. The large eye sockets in the skull are a good way to identify one.
The source saysRoss seals can easily be distinguished from closely related seals by their disproportionately large eyes (70mm in diameter). The large eye sockets in the skull are a good character by which a Ross seal can be identified

Source
02

Australian Antarctic Division 2018

Ross seal. Australian Antarctic Division, 2018.

The page saysa loner
The source saysThey tend to be solitary
The page saysThey may be an adaptation for hunting in dimly lit depths
The source saysTheir enormous eyes may be an adaptation for hunting in the dimly-lit depths
The page saysthey tend to be solitary
The source saysThey tend to be solitary
The page saysRoss seals are slightly smaller on average than leopard and crabeater seals, reaching about 3 metres and 200 kilograms
The source saysRoss seals are slightly smaller on average than leopard and crabeater seals, reaching about 3 metres and 200 kgNote: AAD (2018) is the current institution page; ADW's sex-split ranges (King 1990-era, max 250 cm) were dropped in its favour
The page says70-millimetre eyes that may be an adaptation for hunting in dimly lit depths
The source saysTheir enormous eyes may be an adaptation for hunting in the dimly-lit depthsNote: the 70mm figure is the adw-ross-seal claim above; AAD supplies the dim-light hunting framing
The page saysDense Antarctic pack ice
The source sayslive mainly on the densest pack ice

Source
03

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

AnAge entry for Ommatophoca rossii. AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.

The page saysIn the wild, Ross seals are believed to live up to 21 years
The source saysIn the wild, these animals are believed to live up to 21 years

Source
04

Wege, Bornemann & Bester 2023

Wege, Bornemann & Bester (2023). The nightlife of a Ross seal: diving and haul-out behaviour from the eastern Weddell Sea. Antarctic Science.

The page saysoften dives past 300 metres
The source saysRoss seals mostly dived between 100 and 200 m deep, often > 300 m
The page saysUnlike crabeater and Weddell seals, which remain in the ice year round, Ross seals spend most of their life cycle foraging in the open ocean
The source saysunlike other Antarctic counterparts such as the crabeater seal ( Lobodon carcinophaga ) and Weddell seal ( Leptonychotes weddellii ) that remain in the ice year round, travel away from the Antarctic continent and spend most of their life cycle in the open ocean to forage pelagically
The page saysFive seals tagged in the eastern Weddell Sea mostly dived 100 to 200 metres deep and often beyond 300, usually for 5 to 12 minutes
The source saysrecorded the dive behaviour ( n = 5) and/or haul-out behaviour ( n = 9) of Ross seals in the eastern Weddell Sea (2016–2019). Ross seals mostly dived between 100 and 200 m deep, often > 300 m, and for 5–12 min in duration
The page saysearlier studies recorded occasional dives close to 800 metres
The source saysIn previous studies, Ross seals also dived to depths of 100–300 m, occasionally reaching depths of close to 800 m
The page saysFrom March to July the seals dived deeper at twilight and shallowest at night, and their diving effort was highest at night
The source saysDuring March–July, when Ross seals forage pelagically, diving metrics varied diurnally. The seals dived deeper during twilight and shallowest at night, while the number of dives and diving duration did not follow a clear diurnal pattern. Consequently, diving effort was highest during the night.
The page saysWhy is unknown: the authors suggest the seals may be reaching their aerobic dive limit, which would cap how long each dive lasts
The source saysWhy diving effort (dive residuals) was highest at night is currently unknown. We suggest that the seals are potentially reaching their aerobic dive limit and therefore their dive duration is limited
The page saysThey eat squid and fish, and occasionally crustaceans and bottom-dwelling invertebrates
The source saysThey prey on squid, fish and occasionally crustaceans and benthic invertebratesNote: bottom-dwelling = benthic
The page saysIn the open ocean they take myctophid fish (lanternfish) and cephalopods, and over the continental shelf during their annual moult, Antarctic silverfish
The source saysMyctophid fish and cephalopods are taken while foraging in the open ocean, and Antarctic silverfish (Pleuragramma antarctica) are taken when the seals forage over the continental shelf during their annual moultNote: lanternfish is the common name of the Myctophidae, a gloss rather than a claim
The page saysPups have been sighted from 2 October to 22 November
The source sayswith pups sighted as early as 2 October and as late as 22 November
The page saysThree tracked females that entered the pack ice in the breeding season stayed hauled out for five to seven days at a stretch, broken by one- to three-hour spells in the water
The source saysThree females that entered the pack ice during breeding season were hauled out continuously for 5–7 days, punctuated by water entries for 1–3 h during and/or after such continuous haul-outs over the breeding season
The page saysSquid and myctophid (lantern) fish in open water, plus Antarctic silverfish near the continental shelf during the moult
The source saysMyctophid fish and cephalopods are taken while foraging in the open ocean, and Antarctic silverfish (Pleuragramma antarctica) are taken when the seals forage over the continental shelf during their annual moult
The page saysTagged Ross seals mostly dive between 100 and 200 metres and often go past 300, for 5 to 12 minutes and often more than 20.
The source saysRoss seals mostly dived between 100 and 200 m deep, often > 300 m, and for 5–12 min in duration, often > 20 min
The page saysEarlier tagging studies recorded occasional dives close to 800 metres.
The source saysIn previous studies, Ross seals also dived to depths of 100–300 m, occasionally reaching depths of close to 800 m
The page saysHundreds of Metres Down
The source saysRoss seals mostly dived between 100 and 200 m deep, often > 300 m

Source
05

Bester et al. 2019

Bester et al. (2019). Ross seal distribution in the Weddell Sea: fact and fallacy. Polar Biology.

The page saysThe least-studied of Antarctica's ice-breeding seals
The source saysthe least numerous and least studied of the Antarctic ice-breeding seals
The page saysRoss seals are the least numerous and least studied of the seals that breed on Antarctic pack ice
The source saysthe least numerous and least studied of the Antarctic ice-breeding seals
The page saysRange maps that show them throughout the Weddell Sea are at odds with earlier surveys there
The source saysthe generalised continuous distribution maps of Ross seals throughout the Weddell Sea (e.g., Reeves et al. 2002; Shirihai 2002; Hückstädt 2018) are at odds with results from earlier work (Erickson et al. 1969; Siniff et al. 1970; Erickson and Hofman 1974; Erickson 1984; Erickson and Hanson 1990). Then no Ross seals were sightedNote: the earlier work is the sighting surveys the next sentence of the source describes
The page saysThe evidence suggests they are absent from the Weddell Sea in winter, and from its inner reaches past about 73 degrees south in summer and early autumn, when they occur in number in the eastern Weddell Sea, east of about 30 degrees west
The source saysEvidence suggests that Ross seals are absent from the Weddell Sea during winter, utilizing the northernmost fringes of the pack-ice during the spring breeding (pupping and mating) season. Ross seals are absent from the inner reaches of the Weddell Sea past about 73 o S in summer and early autumn when they occur in number in the eastern Weddell Sea eastwards from about 30 o W longitude.
The page saysDense Antarctic pack ice for breeding and moulting; the open Southern Ocean for the rest of the year
The source saysbecause of their long foraging trips north of the pack-ice into pelagic areas of the Southern Ocean for most of the year and return to the pack-ice only for short periods to breed and moult
The page saysIt is the least numerous and least studied of the Antarctic ice-breeding seals
The source saysthe least numerous and least studied of the Antarctic ice-breeding seals
The page saysFor most of the year it makes long foraging trips north of the pack ice into the open Southern Ocean, and it returns to the pack ice only for short periods to breed and moult
The source saysbecause of their long foraging trips north of the pack-ice into pelagic areas of the Southern Ocean for most of the year and return to the pack-ice only for short periods to breed and moult

Source
06

Loza et al. 2017

Loza et al. (2017). Sensory anatomy of the most aquatic of carnivorans: the Antarctic Ross seal, and convergences with other mammals. Biology Letters.

The page saysCT scans of specimens show changes inside the head too: compared with other true seals, the semicircular canals of the inner ear are narrower and a brain structure called the paraflocculus is smaller, independent of body size
The source saysThe use of non-invasive computed tomography on specimens of this rare animal reveals, relative to other species of phocids, a reduction in the diameters of the semicircular canals and the parafloccular volume. These features are independent of size effects.Note: narrower = reduced diameter; true seals = phocids; the title's 'cranio-sensory anatomy' is the 'inside the head'
The page saysWhales and dolphins show parallel changes, a case of convergent evolution toward aquatic life that stops short of other traits: the Ross seal lacks their reduced eye muscles and shortened neck
The source saysThese transformations parallel those recorded in cetaceans, but these do not extend to other morphological features such as the reduction in eye muscles and the length of the neck, emphasizing the independence of some traits in convergent evolution to aquatic lifeNote: cetaceans (whales and dolphins) is the plain-language gloss for the source's term

Source
07

Southwell et al. 2008

Southwell et al. (2008). Estimating population status under conditions of uncertainty: the Ross seal in East Antarctica. Antarctic Science.

The page saysEven estimating the Ross seal's population status has proved extremely difficult
The source saysestimating the population status of the Ross seal has proved extremely difficult
The page saysEstimating the population status of the Ross seal has proved extremely difficult.
The source saysestimating the population status of the Ross seal has proved extremely difficult
The page saysA 1999/2000 survey of the pack ice off East Antarctica, between 64 and 150 degrees east, gave best estimates of 41,300 to 55,900 seals in that region, with plausible estimates ranging from 20,500 to 226,600.
The source saysa survey was undertaken in 1999/2000 to estimate the status of the Ross seal population in the pack ice off East Antarctica between 64–150°E ... Best estimates of abundance in the survey region ranged from 41 300–55 900 seals. Limits on plausible estimates ranged from 20 500 (lower 2.5 percentile) to 226 600 (upper 97.5 percentile).Note: the answer spells the figures with comma thousands separators; the source uses spaces, same values

Source
08

Hughes et al. 2024

Hughes et al. (2024). The Antarctic Specially Protected Species conservation management tool: Development, use and future outlook. Biological Conservation.

The page saysSince the Antarctic Treaty system first provided for Specially Protected Species in 1964, only the fur seals and the Ross seal have been listed, and the fur seals were de-listed in 2006
The source sayswhich first provided for the designation of Antarctic Specially Protected Species (SPS) in 1964. Over the past 60 years, only the fur seals (genus Arctocephalus) and Ross seal (Ommatophoca rossii) have been listed as SPS, with the fur seals subsequently having been de-listed in 2006
The page saysThe tool has therefore remained little used
The source saysThe SPS conservation tool has therefore remained little used by the ATCM
The page saysA Rarely Used Protection
The source saysThe SPS conservation tool has therefore remained little used by the ATCM

Source
09

Hückstädt 2026

Hückstädt (2026). Ommatophoca rossii. The IUCN Red List of Threatened Species 2026: e.T15269A95971509.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC). Ommatophoca rossii J.E. Gray, 1844, IUCN taxon 15269.

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.