---
title: "What the sources say about the Ross Seal | AnimalTracks.wiki"
description: "43 claims from the Ross Seal profile, each beside the words of the source that backs it."
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---

# What the sources say about the Ross Seal (*Ommatophoca rossii*)

> 43 claims from the Ross Seal profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Ross Seal](https://animaltracks.wiki/animals/ross-seal/)

## Ommatophoca rossii. Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Ommatophoca_rossii/

| The page says | The source says |
| :--- | :--- |
| with enormous eyes | disproportionately large eyes (70mm in diameter) |
| has disproportionately large eyes, 70 millimetres in diameter, which make it easy to distinguish from closely related seals | Ross seals can easily be distinguished from closely related seals by their disproportionately large eyes (70mm in diameter) |
| females average larger than males | Males average smaller than females |
| They have a thick neck, a slender body and the shortest hair and whiskers of any true seal | with a thick neck and a slender body. Members of this species have short body hairs, with the shortest hair and vibrissae of any phocid (note: phocid = true seal, vibrissae = whiskers) |
| 70-millimetre eyes | disproportionately large eyes (70mm in diameter) |
| They 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. | Ross 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 |

## Ross seal. Australian Antarctic Division, 2018.

https://www.antarctica.gov.au/about-antarctica/animals/seals/ross-seal/

| The page says | The source says |
| :--- | :--- |
| a loner | They tend to be solitary |
| They may be an adaptation for hunting in dimly lit depths | Their enormous eyes may be an adaptation for hunting in the dimly-lit depths |
| they tend to be solitary | They tend to be solitary |
| Ross seals are slightly smaller on average than leopard and crabeater seals, reaching about 3 metres and 200 kilograms | Ross seals are slightly smaller on average than leopard and crabeater seals, reaching about 3 metres and 200 kg (note: AAD (2018) is the current institution page; ADW's sex-split ranges (King 1990-era, max 250 cm) were dropped in its favour) |
| 70-millimetre eyes that may be an adaptation for hunting in dimly lit depths | Their enormous eyes may be an adaptation for hunting in the dimly-lit depths (note: the 70mm figure is the adw-ross-seal claim above; AAD supplies the dim-light hunting framing) |
| Dense Antarctic pack ice | live mainly on the densest pack ice |

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

https://genomics.senescence.info/species/entry.php?species=Ommatophoca_rossii

| The page says | The source says |
| :--- | :--- |
| In the wild, Ross seals are believed to live up to 21 years | In the wild, these animals are believed to live up to 21 years |

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

https://doi.org/10.1017/S0954102022000438

| The page says | The source says |
| :--- | :--- |
| often dives past 300 metres | Ross seals mostly dived between 100 and 200 m deep, often > 300 m |
| Unlike crabeater and Weddell seals, which remain in the ice year round, Ross seals spend most of their life cycle foraging in the open ocean | unlike 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 |
| Five seals tagged in the eastern Weddell Sea mostly dived 100 to 200 metres deep and often beyond 300, usually for 5 to 12 minutes | recorded 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 |
| earlier studies recorded occasional dives close to 800 metres | In previous studies, Ross seals also dived to depths of 100–300 m, occasionally reaching depths of close to 800 m |
| From March to July the seals dived deeper at twilight and shallowest at night, and their diving effort was highest at night | During 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. |
| Why is unknown: the authors suggest the seals may be reaching their aerobic dive limit, which would cap how long each dive lasts | Why 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 |
| They eat squid and fish, and occasionally crustaceans and bottom-dwelling invertebrates | They prey on squid, fish and occasionally crustaceans and benthic invertebrates (note: bottom-dwelling = benthic) |
| In the open ocean they take myctophid fish (lanternfish) and cephalopods, and over the continental shelf during their annual moult, Antarctic silverfish | Myctophid 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 (note: lanternfish is the common name of the Myctophidae, a gloss rather than a claim) |
| Pups have been sighted from 2 October to 22 November | with pups sighted as early as 2 October and as late as 22 November |
| Three 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 | Three 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 |
| Squid and myctophid (lantern) fish in open water, plus Antarctic silverfish near the continental shelf during the moult | Myctophid 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 |
| Tagged Ross seals mostly dive between 100 and 200 metres and often go past 300, for 5 to 12 minutes and often more than 20. | Ross seals mostly dived between 100 and 200 m deep, often > 300 m, and for 5–12 min in duration, often > 20 min |
| Earlier tagging studies recorded occasional dives close to 800 metres. | In previous studies, Ross seals also dived to depths of 100–300 m, occasionally reaching depths of close to 800 m |
| Hundreds of Metres Down | Ross seals mostly dived between 100 and 200 m deep, often > 300 m |

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

https://doi.org/10.1007/s00300-019-02610-4

| The page says | The source says |
| :--- | :--- |
| The least-studied of Antarctica's ice-breeding seals | the least numerous and least studied of the Antarctic ice-breeding seals |
| Ross seals are the least numerous and least studied of the seals that breed on Antarctic pack ice | the least numerous and least studied of the Antarctic ice-breeding seals |
| Range maps that show them throughout the Weddell Sea are at odds with earlier surveys there | the 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 sighted (note: the earlier work is the sighting surveys the next sentence of the source describes) |
| The 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 | Evidence 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. |
| Dense Antarctic pack ice for breeding and moulting; the open Southern Ocean for the rest of the year | because 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 |
| It is the least numerous and least studied of the Antarctic ice-breeding seals | the least numerous and least studied of the Antarctic ice-breeding seals |
| For 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 | because 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 |

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

https://doi.org/10.1098/rsbl.2017.0489

| The page says | The source says |
| :--- | :--- |
| CT 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 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') |
| Whales 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 | These 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 life (note: cetaceans (whales and dolphins) is the plain-language gloss for the source's term) |

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

https://doi.org/10.1017/S0954102007000879

| The page says | The source says |
| :--- | :--- |
| Even estimating the Ross seal's population status has proved extremely difficult | estimating the population status of the Ross seal has proved extremely difficult |
| Estimating the population status of the Ross seal has proved extremely difficult. | estimating the population status of the Ross seal has proved extremely difficult |
| A 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. | a 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) |

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

https://doi.org/10.1016/j.biocon.2024.110835

| The page says | The source says |
| :--- | :--- |
| Since 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 | which 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 tool has therefore remained little used | The SPS conservation tool has therefore remained little used by the ATCM |
| A Rarely Used Protection | The SPS conservation tool has therefore remained little used by the ATCM |

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

https://doi.org/10.2305/iucn.uk.2026-1.rlts.t15269a95971509.en

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