---
title: "What the sources say about the European Storm Petrel | AnimalTracks.wiki"
description: "43 claims from the European Storm Petrel profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/european-storm-petrel-1.webp"
canonical: "https://animaltracks.wiki/animals/european-storm-petrel/sources/"
---

# What the sources say about the European Storm Petrel (*Hydrobates pelagicus*)

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

Profile: [European Storm Petrel](https://animaltracks.wiki/animals/european-storm-petrel/)

## Storm Petrel. BTO BirdFacts.

https://www.bto.org/understanding-birds/birdfacts/storm-petrel

| The page says | The source says |
| :--- | :--- |
| most adults weigh between 22.5 and 29.1 grams | All adults 25.6±4.9 g (22.5-29.1 g, N=20482) (note: BTO's 5th/95th percentile range for all adults (British ringing data)) |
| with a wing just over 12 centimeters long | All adults 122.6±3 mm (118-127 mm, N=22122) (note: 122.6 mm converted to cm) |
| The oldest ringed storm petrel on the BTO's books reached 38 years and 17 days, a record set in 2017 | Maximum age from a ringed bird 38 years, 17 days (set in 2017) |
| a typical life expectancy of 11 years for a bird that reaches breeding age, with breeding typically starting at four | Typical life expectancy of bird reaching breeding age 11 years with breeding typically at 4 years |
| BTO nest records show both parents incubate the single egg, typically for 38 to 50 days. | Clutch Size Typical number 1 eggs Observed minimum and maximum 1 eggs Source Incubation Incubation by Male + Female Typical duration 38-50 days (note: 'single egg' from the quote's clutch size of 1 (minimum and maximum 1)) |
| Once hatched, the downy chick typically takes 56 to 73 days to fledge. | Fledging Type of chick Altricial, downy Typical duration 56-73 days |
| weightKg: 0.026 | All adults 25.6±4.9 g (22.5-29.1 g, N=20482) (note: settle #889) |
| a seabird weighing about 25 grams | All adults 25.6±4.9 g (note: settle #889 (vibe.reason)) |

## Hydrobates pelagicus. The IUCN Red List of Threatened Species 2021: e.T22698477A166331807.

https://doi.org/10.2305/iucn.uk.2021-3.rlts.t22698477a166331807.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | IUCN Red List category: Least Concern (LC). |

## Bolton (1996). Energy expenditure, body-weight and foraging performance of Storm Petrels Hydrobates pelagicus breeding in artificial nesting chambers. Ibis.

https://doi.org/10.1111/j.1474-919x.1996.tb08058.x

| The page says | The source says |
| :--- | :--- |
| if that oil supplies all its energy, it accounts for 76% of the weight lost each day on the nest | Assuming the metabolic requirements during incubation are furnished entirely from stomach oil, 76% of the daily mass lost represented stomach oil catabolism. (note: 'all' restates the source's own assumption ('furnished entirely from stomach oil')) |
| the partner comes back once it has regained a threshold body mass of about 31 grams, however long it has spent at sea | The body mass of birds returning from foraging was relatively constant and was unrelated to the amount of time spent foraging at sea, indicating that the decision rule to return from foraging was the acquisition of a threshold level of body mass (about 31 g) |
| If a sitting storm petrel's energy during incubation comes entirely from the oil stored in its stomach, as the study assumed, then burning that oil accounts for 76 percent of the weight it loses each day on the nest. | Assuming the metabolic requirements during incubation are furnished entirely from stomach oil, 76% of the daily mass lost represented stomach oil catabolism. |
| A study of storm petrels breeding in artificial nest chambers measured how fast sitting birds burn energy, both from their carbon dioxide output and from how quickly they lose weight. | Direct measurement of carbon dioxide production using standard respirometry techniques and estimations of metabolic rate based on the rates of mass loss during incubation indicated close agreement between the two methods of estimating energy consumption. |
| A shift on the egg usually ends when the foraging partner returns | Shifts were usually terminated by the return of the foraging partner. |

## Medeiros et al. (2012). Molecular Evidence for Gender Differences in the Migratory Behaviour of a Small Seabird. PLoS ONE.

https://doi.org/10.1371/journal.pone.0046330

| The page says | The source says |
| :--- | :--- |
| The Atlantic's smallest seabird, weighing about 25 grams but migrating from the north-east Atlantic to winter off southern Africa. | H. pelagicus is the smallest Atlantic seabird (∼25 g), and a long-distance migrant between the breeding colonies in the north-east Atlantic and the wintering areas in the south Atlantic and Indian oceans, off southern Africa. |
| wintering as far as the seas off southern Africa | the wintering areas in the south Atlantic and Indian oceans, off southern Africa |
| the smallest seabird in the Atlantic Ocean | H. pelagicus is the smallest Atlantic seabird (∼25 g) |
| it migrates from breeding colonies in the north-east Atlantic to wintering grounds off southern Africa, in the south Atlantic and Indian oceans | a long-distance migrant between the breeding colonies in the north-east Atlantic and the wintering areas in the south Atlantic and Indian oceans, off southern Africa |
| Researchers used DNA to sex pre-breeding birds drawn in by recorded calls on their northward migration past south-west Europe, and found the catch ran 80.8% to 89.7% female across seven years. | Molecular sexing revealed an unexpectedly strong female bias in the sex ratio of pre-breeding European Storm Petrels ( Hydrobates pelagicus ), attracted to playback of conspecific calls during their northwards migration past SW Europe. This bias was consistent across seven years, ranging from 80.8% to 89.7% female |
| Samples from breeding colonies showed no such bias, and the researchers suggest the sexes may differ in migration route or in their colony-prospecting behaviour during migration. | The sex ratio did not differ significantly from unity (i.e., 50% female) among (i) Storm Petrel chicks at a breeding colony in NW France, (ii) adults found dead on beaches in Southern Portugal, (iii) breeding birds attending nest burrows in the UK ... The preponderance of females captured in Southern Europe suggests that the sexes may differ in migration route or in their colony-prospecting behaviour during migration |

## Wilkinson et al. (2026). Under the cover of darkness: Foraging behaviour increases on cloudy, new moon nights in a pelagic seabird. Ibis.

https://doi.org/10.1111/ibi.70104

| The page says | The source says |
| :--- | :--- |
| Many nocturnal seabirds forage more under moonlight, but GPS tracking of storm petrels from one colony found that offshore they forage under the darkest conditions, a pattern strongly influenced by cloud cover. | Nocturnal foraging, identified using GPS‐accelerometry data and a Hidden Markov Model, was concentrated in two areas: shallow coastal waters near the colony and deeper offshore waters near the shelf edge. Generalized additive models revealed that, in offshore areas, European Storm‐petrels forage under the darkest nocturnal conditions, contrasting with the increased activity under moonlit conditions reported for many other nocturnally foraging seabirds. This was strongly influenced by cloud cover |
| smell probably helps the birds detect patches of prey at night, and that bioluminescence may help them spot individual prey by eye | olfaction probably plays an important role in detecting prey patches at night, bioluminescence may aid visual detection of individual prey items |

## Carboneras, Jutglar & Kirwan (2020). European Storm-Petrel (Hydrobates pelagicus). Birds of the World.

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

| The page says | The source says |
| :--- | :--- |
| Pelagic north-east Atlantic and Mediterranean waters | Eastern Atlantic Ocean, breeding in northeastern Atlantic, from southern Iceland and western Norway south through northern and western Britain to northwestern France, northern Spain and Canary Islands. ... Mediterranean from eastern Spain east to Greece |
| Mainly plankton picked from the sea surface by hovering; the Mediterranean subspecies feeds mainly by diving for pelagic fish instead | It feeds mainly on plankton by hovering over the surface ... It feeds mainly on pelagic fishes by diving, unlike nominate |
| Atlantic birds feed mainly by hovering over the surface and picking off plankton | It feeds mainly on plankton by hovering over the surface |
| the larger, heavier-billed Mediterranean subspecies, melitensis, feeds mainly by diving for pelagic fish | differs in its larger size with proportionally smaller tail and heavier bill ... It feeds mainly on pelagic fishes by diving, unlike nominate |
| Birds of the World lists them as two subspecies of one species, but notes the Mediterranean race "may be better treated as a distinct species." | Subspecies (2) ... Thalassidroma melitensis Schembri, 1843 [type locality: Malta]. This race may be better treated as a distinct species. |
| It is larger, with a heavier bill and a proportionally smaller tail. | Similar to nominate, but differs in its larger size with proportionally smaller tail and heavier bill. |
| The two also differ in voice and coloration | The two also differ in voice and coloration |
| the Mediterranean birds breed earlier | Besides, melitensis breeds earlier than pelagicus |
| feeds mainly by hovering just over the sea, picking plankton off the surface | It feeds mainly on plankton by hovering over the surface (note: settle #889 (vibe.reason)) |

## Watson, Bolton & Monaghan (2014). Out of sight but not out of harm's way: Human disturbance reduces reproductive success of a cavity-nesting seabird. Biological Conservation.

https://doi.org/10.1016/j.biocon.2014.03.020

| The page says | The source says |
| :--- | :--- |
| nesting in crevices in stone walls, boulder beaches and old buildings | storm petrels nest in crevices in dry stone walls, boulder beaches, loose rock scree, and abandoned buildings |
| Storm petrels are active in their colonies only at night | storm petrels are only active within the colony at night |
| On Shetland's Mousa they nest in crevices in dry stone walls, boulder beaches, rock scree and abandoned buildings | On Mousa, storm petrels nest in crevices in dry stone walls, boulder beaches, loose rock scree, and abandoned buildings |
| Mousa has no mice, rats or cats, and its only mammalian predator, the Eurasian otter, rarely takes storm petrel nests | The island remains free from mice, rats and cats; the only mammalian predator present is the Eurasian otter Lutra lutra, which rarely predates on storm petrel nests |
| a 2014 study reported that the colony had more than doubled in size since 1996 | The storm petrel colony at Mousa has more than doubled in size since 1996 (note: 2014 is the year of Watson, Bolton & Monaghan (the cited reference)) |

## Ruffino et al. (2009). Invasive rats and seabirds after 2,000 years of an unwanted coexistence on Mediterranean islands. Biological Invasions.

https://doi.org/10.1007/s10530-008-9394-z

| The page says | The source says |
| :--- | :--- |
| Across a survey of about 300 western Mediterranean islands, rat presence was a limiting factor, at the regional scale, only for the storm petrel's abundance, while the three shearwater species there were shaped more by island characteristics | A database gathering information on approximately 300 Western Mediterranean islands was analyzed ... At the regional scale, rat presence was only a limiting factor in the abundance of the smallest seabird, the storm petrel (Hydrobates pelagicus), while the distribution and abundance of the three shearwaters were more influenced by island characteristics. |

## Belliure, Mínguez & De León (2003). Self-odour recognition in European storm-petrel chicks. Behaviour.

https://doi.org/10.1163/156853903770238382

| The page says | The source says |
| :--- | :--- |
| its chicks can apparently recognize their own body odor | between their own odour and the body scent of a conspecific chick. Storm-petrel chicks can apparently recognize their own body odour, even when tested against the body scent of a conspecific. |
| chicks can apparently recognize their own body odor, even when tested against the scent of another storm petrel chick | between their own odour and the body scent of a conspecific chick. Storm-petrel chicks can apparently recognize their own body odour, even when tested against the body scent of a conspecific. |
| the researchers suggest such individual odors may help a bird recognize its nest | Individually distinctive odours may play an important role in facilitating nest recognition. |

## Sanz-Aguilar et al. (2020). Infestation of small seabirds by Ornithodoros maritimus ticks: Effects on chick body condition, reproduction and associated infectious agents. Ticks and Tick-borne Diseases.

https://doi.org/10.1016/j.ttbdis.2019.101281

| The page says | The source says |
| :--- | :--- |
| In a cave colony on Espartar Island in Spain's Balearic Islands, researchers studied the soft tick Ornithodoros maritimus. | soft tick Ornithodoros maritimus ... storm petrels Hydrobates pelagicus breeding in a large colony in a cave of Espartar Island, in the Balearic archipelago |
| Fewer chicks survived deep in the cave, the most infested area, than near the entrance, and chicks carrying more ticks were in poorer body condition. | Lower nestling survival was recorded in the most infested area, deep in the cave, compared to the area near the entrance. The parasite load was negatively associated with the body condition of the nestlings. |
| Some pools of ticks tested positive for a Borrelia bacterium with 99% sequence identity to B. turicatae, a relapsing-fever Borrelia. | 4 pools tested positive for a Borrelia species which was determined by targeted nested PCR to have a 99% sequence identity with B. turicatae, a relapsing fever Borrelia |