---
title: "What the sources say about the Snow Petrel | AnimalTracks.wiki"
description: "36 claims from the Snow Petrel profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/snow-petrel-1.webp"
canonical: "https://animaltracks.wiki/animals/snow-petrel/sources/"
---

# What the sources say about the Snow Petrel (*Pagodroma nivea*)

> 36 claims from the Snow Petrel profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Snow Petrel](https://animaltracks.wiki/animals/snow-petrel/)

## McClymont et al. (2022). Snow petrel stomach-oil deposits as a new biological archive of Antarctic sea ice. Past Global Changes Magazine.

https://doi.org/10.22498/pages.30.2.82

| The page says | The source says |
| :--- | :--- |
| An all-white Antarctic seabird that sometimes nests hundreds of kilometers inland and spits stomach oil that can build up around its nest for thousands of years | The oil is regurgitated as a defense mechanism against predators, and can accumulate around the nest entrance over hundreds or thousands of years (note: tagline; all-white is aad-snow-petrel ("an all-white, small fulmarine petrel"); inland distance is bow-snow-petrel-2020 ("sometimes as far as 325 km inland")) |
| A defensive spit of partly digested stomach oil that builds up into nest deposits, some radiocarbon-dated to the last ice age | radiocarbon dating has confirmed that these seabirds were present onshore during the Last Glacial Maximum ... stomach oil generated from partially digested krill, squid, and fish. The oil is regurgitated as a defense mechanism against predators, and can accumulate around the nest entrance (note: stats.superpower) |
| A snow petrel spits oil made from partially digested krill, squid and fish as a defense against predators, and the oil can accumulate around the nest entrance over hundreds or thousands of years | They spit stomach oil in defence ... returning with an energy-rich stomach oil generated from partially digested krill, squid, and fish. The oil is regurgitated as a defense mechanism against predators, and can accumulate around the nest entrance over hundreds or thousands of years |
| The deposits are a mix of stomach oil, guano, feathers and wind-blown sediment, and one studied deposit shows distinct layers that built up at rates of up to 30 millimeters per thousand years | Vertical section through stomach-oil deposit WMM7, showing distinct layers building up through time at rates of up to 30 mm per 1000 years ... The deposits contain a mixture of stomach oils, guano, feathers, and wind-blown sediments (note: the rate is the Fig. 1 caption for one deposit, WMM7, and is scoped to it) |
| Radiocarbon dating of these deposits has confirmed that snow petrels were present onshore during the Last Glacial Maximum, about 23,000 to 19,000 years ago, when sea ice likely covered twice today's extent | radiocarbon dating has confirmed that these seabirds were present onshore during the Last Glacial Maximum (~23-19 kyr before present (BP)), even when sea-ice extent was likely doubled relative to today (note: "23,000 to 19,000 years ago" is the source's "~23-19 kyr before present"; kyr = thousand years) |
| A defense that outlives the bird | The oil is regurgitated as a defense mechanism against predators, and can accumulate around the nest entrance over hundreds or thousands of years (note: blockquote lead-in) |
| nesting in crevices and scree on nunataks, mountains that poke through the Antarctic Ice Sheet | they nest in crevices, under boulders, and in scree slopes on the mountains (nunataks) which poke through the Antarctic Ice Sheet |
| Snow petrels forage in the sea ice, traveling hundreds of kilometers from their nests | They continue to forage in the sea ice, traveling hundreds of kilometers from their nests |
| For one Dronning Maud Land nest site, researchers mapped a mean breeding-season foraging range of about 700 kilometers and a maximum of about 2,600 | Mean breeding-season foraging range (~700 km) Max. breeding-season foraging range (~2600 km) (note: Fig. 2 map legend; the figure is the map for Dronning Maud Land deposit WMM7 ("Figure 2: Left: Dronning Maud Land stomach-oil deposit WMM7"), so the ranges are scoped to that site) |
| Researchers identify krill in a deposit from elevated copper and particular fatty acids, and the deposits keep a record of both the birds' diet and the sea ice where they fed | the deposits are both an archive of snow petrel diet and the sea-ice environment where they fed ... Isolating the biochemical fingerprints of those prey allows us to reconstruct past diets, for example, identifying krill from elevated copper and specific fatty acid distributions (note: FAQ 1) |
| The oil is generated from whatever krill, squid or fish a bird has partly digested, and old layers keep a chemical record of that meal | returning with an energy-rich stomach oil generated from partially digested krill, squid, and fish (note: FAQ 1) |
| the stomach oil snow petrels spit at predators, which builds up around a nest entrance over hundreds or thousands of years | The oil is regurgitated as a defense mechanism against predators, and can accumulate around the nest entrance over hundreds or thousands of years (note: settle #889 (vibe.reason)) |

## Steiger et al. (2008). Avian olfactory receptor gene repertoires: evidence for a well-developed sense of smell in birds? Proceedings of the Royal Society B: Biological Sciences.

https://doi.org/10.1098/rspb.2008.0607

| The page says | The source says |
| :--- | :--- |
| Birds are widely regarded as relying mainly on sight and hearing | with birds widely regarded as relying primarily on visual and auditory inputs |
| the snow petrel's olfactory bulb ratio (the bulb's greatest diameter against the cerebral hemisphere's) | the OBR, the ratio of the greatest diameter of the olfactory bulb to the greatest diameter of the cerebral hemisphere in per cent |
| is 12 times the black-capped chickadee's, one of the largest measured in birds | the OBR of the snow petrel ( P. nivea ) is 12 times larger than that of the black-capped chickadee ( Poecile atricapillus ; Bang & Cobb 1968 ) ... it has one of the largest OBRs measured in birds (note: OBR = olfactory bulb ratio) |
| Its estimated set of smell-receptor genes is relatively small, though, which the researchers suggest fits a specialist daytime forager whose olfactory system may be highly sensitive to only a limited variety of odours | a relatively small estimated OR gene repertoire. However, in contrast to the kiwi and the kakapo, the snow petrel is a specialist diurnal forager ( Ainley et al . 1984 ; Warham 1996 ) and it is plausible that its olfactory system has evolved to be highly sensitive to only a limited variety of odours. (note: OR genes = olfactory receptor genes; "may be" keeps the paper's "plausible") |

## Snow petrel. Australian Antarctic Program, 2010.

https://www.antarctica.gov.au/about-antarctica/animals/flying-birds/snow-petrel/

| The page says | The source says |
| :--- | :--- |
| Mainly fish, with some squid, other molluscs and krill, plus seal placenta and the carcasses of seals, whales and penguins | At sea, snow petrels eat mainly fish, some cephalopods (squid), other molluscs, and euphausiids. They also feed on seal placenta and the carcasses of dead seals, whales and penguins (note: stats.diet; euphausiids = krill) |
| Its plumage is all white apart from dark eyes, a small black bill and blue-grey feet | Snow petrels are an all-white, small fulmarine petrel with conspicuous dark eyes, small black bill and bluish-grey feet. |
| it is almost entirely restricted to cold Antarctic waters around pack ice, icebergs and ice floes | Snow petrels are almost entirely restricted to cold antarctic waters and are associated with pack ice, icebergs and ice floes. |
| Snow petrels breed on South Georgia, the South Sandwich and South Orkney Islands, Bouvet, the Balleny Islands, Scott Island, and at numerous sites on the Antarctic Peninsula and continent | Snow petrels breed on South Georgia, the South Sandwich Islands, South Orkney Islands, Bouvet, the Balleny Islands, and Scott Island and at numerous localities on the Antarctic Peninsula and Antarctic Continent. |
| Colonies usually sit on cliffs near the sea | Snow petrels nest colonially in small to large colonies on cliffs, usually near the sea, but also inland. |
| One white egg is laid in a pebble-lined scrape, usually in a rock crevice, between late November and mid-December. Incubation takes 41 to 49 days and the chick is brooded for 8 days, then stays in the nest for another 7 weeks, leaving between late February and mid-May | The nest is a simple pebble-lined scrape usually in a deep rock crevice with overhanging protection. One white egg is laid in late November to mid-December. The egg is incubated for 41-49 days and the chick is brooded for 8 days. The chick then remains in the nest for an additional 7 weeks. Snow petrel chicks leave the nest in late-February to mid-May. |
| At sea they eat mainly fish, with some squid, other molluscs and krill, and they also feed on seal placenta and the carcasses of dead seals, whales and penguins | At sea, snow petrels eat mainly fish, some cephalopods (squid), other molluscs, and euphausiids. They also feed on seal placenta and the carcasses of dead seals, whales and penguins (note: euphausiids = krill) |
| They tend to fly low over the water but very high over land, which helps them avoid predators such as South Polar skuas | Snow petrels tend to fly low over the water but very high over land to avoid predators such as South Polar skuas. (note: FAQ 3) |
| Skuas are still major predators, and weather is another danger: heavy snow that blocks nest entrances can make adults abandon their eggs, or leave chicks to starve | Skuas are major predators, but severe weather conditions, especially heavy snow that blocks nest entrances, may cause adults to abandon their eggs or chicks to starve. (note: FAQ 3) |

## Carboneras, Jutglar & Kirwan (2020). Snow Petrel (Pagodroma nivea). Birds of the World.

https://doi.org/10.2173/bow.snopet1.01

| The page says | The source says |
| :--- | :--- |
| breeding colonially on coastal cliffs and on inland nunataks up to 325 kilometers from the sea | Colonial nesters, Snow Petrels breed on cliffs and rock faces sometimes as far as 325 km inland. (note: stats.habitat) |
| birds sometimes breed as far as 325 kilometers inland | Colonial nesters, Snow Petrels breed on cliffs and rock faces sometimes as far as 325 km inland. |

## Chastel, Weimerskirch & Jouventin (1993). High annual variability in reproductive success and survival of an Antarctic seabird, the snow petrel Pagodroma nivea: A 27-year study. Oecologia.

https://doi.org/10.1007/bf00341328

| The page says | The source says |
| :--- | :--- |
| At Pointe Géologie in Adélie Land, birds first bred at 9.9 years old on average, and annual adult survival was 93.4% across 21 years of data, though it varied | nesting at Pointe Géologie Archipelago, Adélie Land, Antarctica between 1963 and 1990; 21 years of data on adult survival and 27 years of data on breeding success are available. The average age of first return and first breeding were 8.1 and 9.9 years respectively ... Annual adult survival (93.4%), though variable |

## Barbraud et al. (2000). Effect of sea-ice extent on adult survival of an Antarctic top predator: the snow petrel Pagodroma nivea. Oecologia.

https://doi.org/10.1007/s004420000481

| The page says | The source says |
| :--- | :--- |
| A later study on Pétrels Island, Terre Adélie, found 44% of the year-to-year variation in adult survival from 1981 to 1997 was linked, inversely, to how far winter sea ice extended offshore | Time- and sex-specific annual variation in adult survival was estimated using capture-mark-recapture of petrels nesting at Pétrels Island, Terre Adélie, 1981-1997. On the basis of a regression analysis, 44% of the variation was linked inversely to the latitudinal extent of sea-ice during winter (June) in the region offshore of the study colony |

## Jouventin & Viot (1985). Morphological and genetic variability of Snow Petrels Pagodroma nivea. Ibis.

https://doi.org/10.1111/j.1474-919x.1985.tb04839.x

| The page says | The source says |
| :--- | :--- |
| the species varies greatly in size: the largest birds are over twice as heavy as the smallest | Snow Petrels vary greatly in size, the largest birds being over twice as heavy as the smallest. |
| Two forms are recognized, the small Pagodroma nivea nivea and the large P. n. major | a low latitude one inhabited by small birds Pagodroma nivea nivea , and one in higher latitudes characterized by large birds P. n. major (note: FAQ 2; "Two morphological types have been distinguished" in the same abstract; Birds of the World lists both as subspecies) |
| One proposal is that during the Quaternary glaciations small birds survived in a lower-latitude refuge and large birds in a higher-latitude one, then met again when the ice retreated and interbred, creating a hybrid zone | We propose that during the quaternary glaciations, the Antarctic continent provided no refugia for this species, but, when glaciation ended, Snow Petrels re-established colonies, coming from two refugia, a low latitude one inhabited by small birds Pagodroma nivea nivea, and one in higher latitudes characterized by large birds P. n. major. Reproductive isolation broke down, and a hybridization zone was created. (note: FAQ 2) |

## Pagodroma nivea. AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.

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

| The page says | The source says |
| :--- | :--- |
| Adults weigh 268 grams on average | Adult weight 268 g (note: AnAge's life-history traits are averages ("Life history traits (averages)")) |
| Individuals have lived at least 46 years in the wild | Maximum longevity 46 years (wild) |
| weightKg: 0.27 | Adult weight 268 g (note: settle #889) |

## Pagodroma nivea. The IUCN Red List of Threatened Species 2018: e.T22697885A132611127.

https://doi.org/10.2305/iucn.uk.2018-2.rlts.t22697885a132611127.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | IUCN category (GBIF's copy of the Red List): Least Concern (note: stats.conservationStatus; category read through GBIF's copy of the 2018 Red List assessment, per source:prefetch. Hand check: only the category was read from the Red List (iucnredlist.org refuses scripts), so anything else in the assessment is unverified, but nothing else from the assessment is claimed on this page.) |