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European storm-petrel (Hydrobates pelagicus)

The following has been adapted from original text by P. Ian Mitchell and Stephen F. Newton in Seabird Populations of Britain and Ireland (with permission from A&C Black, London).

 

European storm-petrels are pelagic, returning to land only to breed, choosing to nest on remote offshore islands where nocturnal access by surveyors is often difficult and dangerous. They nest below ground, appearing above ground only during darkness and are much more widespread in the UK than Manx shearwaters and Leach's storm-petrels. These characteristics of European storm-petrel behaviour and distribution have meant that obtaining accurate estimates of breeding numbers has been virtually impossible.

Conservation status

European storm-petrel is currently identified as a conservation priority in the following:

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International importance

UK Population

Biogeographic Population

% World Population

24,260 AOS*

5.2 (ssp. pelagicus)

5.1

*AOS = Apparently Occupied Sites

The UK population figure was derived from data in Mitchell, P.I., Newton, S.F., Ratcliffe, N. and Dunn, T.E. (eds.) 2004. Seabird Populations of Britain and Ireland. Poyser, London. This was also the source of figures for the Biogeographic and World populations. 

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UK population estimates and change 1969–2002 (census data)

Both Operation Seafarer and the SCR Census had largely to guess at the location of many colonies, let alone make an accurate estimate of size. Consequently, the results of Seabird 2000 represented the first accurate baseline estimate of the number of European storm-petrels breeding in the UK. Tape-playback was used to count apparently occupied sites (AOS) of breeding European storm-petrels. The method involves playing the species' calls to elicit a response from adults occupying burrows during the day whilst incubating. Unfortunately not all adults present at a colony will respond to taped calls, thus counts of responses underestimate the number of AOS and have to be adjusted by a response rate measured at the colony.

Evidence of possible or probable breeding (e.g. birds present in suitable habitat during the breeding season) obtained during Operation Seafarer and SCR Census and from other sources was used as a basis for selection of sites to survey during Seabird 2000. However, of the 164 islands (in Britain and Ireland) that were surveyed for European storm-petrels during Seabird 2000, breeding had not previously been confirmed or suspected on 98 islands. Surveys were not possible on 17 islands (e.g. inaccessible colonies) where breeding was either confirmed or suspected during the last 30 years and on a further eight where breeding had been suggested from historical records prior to 1969. It is highly unlikely that any substantial colonies (i.e. greater than 100 pairs) were missed.

 

 

Operation Seafarer

(1969-70)

Seabird Colony Register

(1985-88)

Seabird 2000

(1998–2002)

UK Population estimate (AOS*)

n/a

n/a

25,650

% change since previous census

n/a

n/a

n/a

*AOS = Apparently Occupied Sites

For census results for individual countries and Ireland, the Channel Islands and the Isle of Man see under relevant sections below.

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Distribution/abundance

The Seabird 2000 census provides the most comprehensive recent assessment of the distribution and abundance of breeding seabirds. Numbers of European storm-petrel found in different regions, and a map showing location and size of colonies, is provided in the Seabird 2000 European storm-petrel results page.

The locations sampled during the annual Seabird Monitoring Programme provide some information on distribution and are accessible via the Seabird Monitoring Programme online database.

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Annual abundance and productivity by geographical area

With reference to the regional accounts below please note the following:

Breeding abundance: graphs of abundance index with 95% CLs are only shown for a region where the trend produced has been deemed accurate (see methods of analysis). Where a trend was thought to be inaccurate, graphs of abundance at major colonies in a region may be shown instead, particularly if such colonies hold greater than 10% of the regional population, are monitored frequently and may thus help illustrate regional population fluctuations outwith national censuses. Occasionally, too few data have been collected regionally to produce either of these.

Productivity: graphs of productivity are only shown if analysis of breeding success data produced a significant result for regional and/or year effects (again see methods of analysis). If results were not significant, then a regional mean productivity value is given. However, on some occasions too few data are available from which to provide a meaningful average. Furthermore, for 11 species where the quality of monitoring data available was considered high, population viability analysis was undertaken at the UK level and the results of this are also reported.

 

United Kingdom

Breeding Abundance

The first comprehensive estimate of European storm-petrel population size was obtained during the Seabird 2000 Census, when 25,650 AOS were recorded. Due to the logistical difficulty in monitoring of this nocturnal and burrow-nesting species, little information exists on population trends, although survey work at the largest UK colony on Mousa has been carried out more frequently between 2008 and 2015. In 2008, Mousa was estimated to hold 11,781 AOS, an almost 120% increase on the 5,410 AOS recorded during Seabird 2000. A tape playback survey in 2015 estimated a population size of 10,778 AOS1, which still represented an almost 100% increased since Seabird 2000. A similar increase of 109% occurred on the Treshnish Isles of Fladda, Lunga and Sgeir a' Chaisteil from 4,127 in 1996 to 8,664 AOS in 2018. These recent counts may reflect an overall increase in the UK population size of European storm-petrels, although this will only be known for certain when the Seabirds Count census is complete.

 

Productivity

No systematic data on the productivity of European storm-petrels in the UK have been submitted to the SMP.

 

Scotland

Population estimates and change 1969–2002 (census data)

 

Operation Seafarer    

(1969-70)

Seabird Colony Register    

(1985-88)

Seabird 2000    

(1998–2002)

Population estimate (AOS*)

n/a

n/a

21,370

% change since previous census   

n/a

n/a

n/a

*AOS = Apparently Occupied Sites

 

Breeding Abundance

Seabird 2000 estimated that Scotland held 21,370 AOS of European storm-petrel, the first comprehensive estimate obtained for the species. Almost all colonies are found on offshore islands to the west and north of the mainland. Over 50 colonies are known but only three held more than 1,000 AOS during Seabird 2000; Mousa (5,410 (from data re-analysed in 2010, originally 6,800 AOS)2, Treshnish Isles (5,040) and Priest Island (4,400). Due to the logistical difficulty in monitoring this nocturnal and burrow-nesting species, little information exists on population trends. A tape playback survey on Mousa in 2015 estimated a population size of 10,778 AOS1, which represented an almost 100% increased since Seabird 2000. A similar increase of 109% occurred on the Treshnish Isles of Fladda, Lunga and Sgeir a' Chaisteil from 4,127 in 1996 to 8,664 AOS in 2018. On Priest Island, a survey estimated 4,259 AOS in 2014 which represented a slight (-3.2%) decline since the island was surveyed during Seabird 2000. These recent counts may reflect an overall increase in the Scottish population size of European storm-petrels, although this will only be known for certain when the Seabirds Count census is complete.

 

Productivity

No systematic data on the productivity of European storm-petrels in Scotland have been submitted to the SMP.

 

England

Population estimates and change 1969–2002 (census data)

 

Operation Seafarer    

(1969-70)

Seabird Colony Register    

(1985-88)

Seabird 2000    

(1998–2002)

Population estimate (AOS*)

n/a

n/a

1,475

% change since previous census   

n/a

n/a

n/a

*AOS = Apparently Occupied Sites

 

Breeding Abundance

In England, European storm-petrel is confined as a breeding species to the Isles of Scilly. Intensive surveys during Seabird 2000, covering all islands in the archipelago, found 11 colonies and estimated a total population of 1,475 AOS with the majority of these on Annet (938). Melledgan (140 AOS) and Round Island (183 AOS) were the only other islands to hold over 100 AOS. A repeat survey of the archipelago in 2015 found 14 colonies holding 1,299 AOS3, indicating that the English population on the islands may have experienced a slight decline since Seabird 2000.

 

Productivity

No systematic data on the productivity of European storm-petrels in England have been submitted to the SMP.

 

Wales

Population estimates and change 1969–2002 (census data)

 

Operation Seafarer    

(1969-70)

Seabird Colony Register    

(1985-88)

Seabird 2000    

(1998–2002)

Population estimate (AOS*)

n/a

n/a

2,805

% change since previous census   

n/a

n/a

n/a

*AOS = Apparently Occupied Sites

 

Breeding Abundance

Seabird 2000 found 2,805 AOS of European storm-petrel breeding at six colonies in Wales. Only one small colony was found in Gwynedd, on Bardsey, with the other five in Dyfed. By far the most important colony was on Skokholm where 2,450 AOS were found. Due to the logistical difficulty in monitoring this nocturnal and burrow-nesting species, little information exists on population trends, with all recent data collected from a few small colonies on Bishop and Clerks Islands, and Grassholm. In 2010, 149 AOS were recorded on the Bishop and Clerks Islands compared to 108 AOS during Seabird 2000. The small colony on Grassholm (where 4, 3 and 11 AOS were recorded in 2010, 2012 and 2014, respectively), was unknown at the time of Seabird 2000. On Ramsey Island seven AOS were recorded in 2018. For the first time since monitoring began, two AOS were found in 2018 on Middleholm which is part of the Skomer, Skokholm and the Seas off Pembrokeshire SPA.

 

Productivity

No systematic data on the productivity of European storm-petrels in Wales have been submitted to the SMP.

 

Northern Ireland

European storm-petrel does not breed in Northern Ireland.

 

Republic of Ireland

Population estimates and change 1969–2002 (census data)

 

Operation Seafarer    

(1969-70)

Seabird Colony Register    

(1985-88)

Seabird 2000    

(1998–2002)

Population estimate (AOS*)

n/a

n/a

99,065

% change since previous census   

n/a

n/a

n/a

*AOS = Apparently Occupied Sites

 

Breeding Abundance

During Seabird 2000, 30 colonies in the Republic of Ireland were known to hold breeding European storm-petrels, all located on the west coast between counties Kerry and Donegal. Of these, 12 were surveyed but the populations of the remaining colonies could only be estimated. Surveyed colonies were found to hold 57,110 pairs with another 41,955 pairs estimated for un-surveyed colonies. The most important colonies surveyed were all in Co. Kerry; Inishtooskert (27,297 pairs), Great Skellig (9,994 pairs), Inishvickillane (6,394 pairs) and Puffin Island (5,177 pairs). Only three other colonies hold over 1,000 pairs. The largest colony for which an estimate only was made was Inishtearaght at 15,000 pairs with five others each estimated to hold between 3,000 and 8,000 pairs. Due to the logistical difficulty in monitoring this nocturnal and burrow-nesting species, no information exists as to population trends and no sizable colonies have been re-surveyed since Seabird 2000. The recent Republic of Ireland Seabird Census (2015-2018) did not publish a population estimate of European storm petrels due to on-going survey work4.

 

Productivity

No systematic data on the productivity of European storm-petrels in the Republic of Ireland have been submitted to the SMP.

 

All Ireland

Population estimates and change 1969–2002 (census data)

 

Operation Seafarer    

(1969-70)

Seabird Colony Register    

(1985-88)

Seabird 2000    

(1998–2002)

Population estimate (AOS*)

n/a

n/a

99,065

% change since previous census   

n/a

n/a

n/a

*AOS = Apparently Occupied Sites

 

Breeding Abundance

Within Ireland, the European storm-petrel nests only in the Republic of Ireland. Thus, all data and text for the Republic of Ireland is also pertinent to the status of the species for the whole of Ireland.

 

Productivity

No systematic data on productivity have been collected as part of the SMP.

 

Isle of Man

European storm-petrel does not breed on the Isle of Man.

 

Channel Islands

Population estimates and change 1969–2002 (census data)

 

Operation Seafarer    

(1969-70)

Seabird Colony Register    

(1985-88)

Seabird 2000    

(1998–2002)

Population estimate (AOS*)

n/a

n/a

60

% change since previous census   

n/a

n/a

n/a

*AOS = Apparently Occupied Sites

 

Breeding Abundance

During Seabird 2000, only one colony in the Channel Islands was surveyed, Burhou which lies off the coast of Alderney. This small colony held 60 AOS in 2002. Several more colonies are suspected to exist but probably hold no more than a few pairs. Due to the logistical difficulty in monitoring this nocturnal and burrow-nesting species, little information exists as to population trend at Burhou during the last 16 years. Routine monitoring at this colony recorded 90 AOS in 2006, falling to 40 AOS in 2008 with only 28 AOS recorded in 2011.

 

Productivity

No systematic data on the productivity of European storm-petrels on the Channel Islands have been submitted to the SMP.

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UK phenology, diet, survival rates

No data have been collected as part of the Seabird Monitoring Programme.

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References

1 Bolton, M., Sheehan, D., Bolton, S.E., Bolton J.A.C. and Bolton J.R.F. 2017. Resurvey reveals arrested population growth of the largest UK colony of European Storm-petrels Hydrobates pelagicus, Mousa, Shetland. Seabird, 30, 15–30.

2 Bolton, M., Brown, J.G., Moncrieff, H., Ratcliffe, N. and Okill, J.D. 2010. Playback re-survey and demographic modelling indicate a substantial increase in breeding European Storm-petrels Hydrobates pelagicus at the largest UK colony, Mousa, Shetland. Seabird23, 14–24.

3 Heaney, V., and St Pierre, P. 2015. The status of seabirds breeding in the Isles of Scilly 2015. Isles of Scilly Seabird Recovery Project Report 2015. Unpublished RSPB Report, Sandy.

4 Cummins, S., Lauder, C., Lauder, A. and Tierney, T. D. 2019. The Status of Ireland’s Breeding Seabirds: Birds Directive Article 12 Reporting 2013 – 2018. Irish Wildlife Manuals, No. 114. National Parks and Wildlife Service, Department of Culture, Heritage and the Gaeltacht, Ireland.

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Partners

Data have been provided to the SMP by the generous contributions of its partners, other organisations and volunteers throughout Britain and Ireland. Partners to the SMP are: BirdWatch Ireland; The British Trust for Ornithology; UK Centre for Ecology and Hydrology; Natural Resources Wales; Department of Environment, Food and Agriculture (Isle of Man); Department of Environment, Heritage and Local Government (Republic of Ireland); States of Guernsey Government; JNCC; Manx Birdlife; Manx National Heritage; The National Trust; National Trust for Scotland; Natural England; Northern Ireland Department of Agriculture, Environment and Rural Affairs; The Royal Society for the Protection of Birds; Scottish Natural Heritage; Seabird Group; Shetland Oil Terminal Environmental Advisory Group; Scottish Wildlife Trust.  More about the SMP partners >>

 

Image of European storm-petrel appears courtesy of Ian Rendall ©, is subject to international copyright law and may not be reproduced in any form whatsoever.

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Categories:

SMP Report 1986–2018

Published: .

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