European Storm-petrel Hydrobates pelagicus

Status;  International importance;  Population estimates;  Distribution;  Annual abundance/ productivity; Phenology/diet/survival

 

Description

European Storm-petrel vignette

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. Consequently, 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.

 


Conservation status

 

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

Amber listed in Birds of Conservation Concern 3 (2009 update)

EC Birds Directive - e.g. listed in Annex 1 and as a migratory species

(further information on Conservation Designations for UK Taxa)

Not listed in Birds of Conservation Concern in Ireland 2008-2013 (2013 update)

 


International importance

 

UK Population % Biogeographic Population % World Population
25,700 AOS* 5.2 (ssp. pelagicus) 5.1

 

* AOS = Apparently Occupied Sites

The UK population figure (rounded to the nearest hundred) 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.

 


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

 

The results of Seabird 2000 represented the first accurate baseline estimate of the number of European storm-petrels breeding in the UK. A method called 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 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 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.

 


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 where colonies are found and how large they are, is provided in the Seabird 2000 European storm-petrel results page (PDF,  1.1 mb).

 

An interactive map is available on the NBN Gateway, where you can filter to display only the Seabird 2000 data.  For more recent, but less comprehensive, coverage view the distribution on the NBN with all available contributing datasets

 

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

 


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.   

 



 

Breeding abundance

 

The first comprehensive estimate of population size of European storm-petrel was obtained during the Seabird 2000 Census, when close to 25,700 pairs were counted. Due to the logistical difficulty in monitoring this nocturnal and burrow-nesting species, little information exists as to population trends although survey work at the largest UK colony, on Mousa in Shetland, suggests it doubled in size between 1996 and 2008. Details of the few colonies monitored since Seabird 2000 can be found under the relevant country sections.

 

Productivity

 

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

 

 

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 12,370 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 (6,800), Treshnish Isles (5,040) and Priest Island (4,400).  A re-survey carried out on Mousa, estimated 11,781 AOS there in 2008. Methods were identical to the previous survey (in 1996) with re-analysis of the earlier data suggesting the estimate of 6,800 was too high due to some calculation inaccuracies and should be reduced to 5,410 AOS1. Thus, the survey in 2008 suggests an increase of almost 118% has occurred over twelve years. On Priest Island, a survey estimated 2,168 AOS in 2009 which would represent a decline since the island was surveyed during Seabird 2000 although it is unknown whether this reflects a real change or differences due to sampling methodology. After a few birds were heard calling on Noss (Shetland) during recent breeding seasons a survey of accessible suitable habitat found 18 AOS in 2010 and 20 AOS in 2011. Five AOS were also recorded on Copinsay (Orkney) in 2011. No apparently occupied sites were recorded on Noss during Seabird 2000 so this appears to be a recent colonisation. Due to the logistical difficulty in monitoring this nocturnal and burrow-nesting species, little other information exists as to population trends. On Eilean Hoan (Sutherland), 167 AOS were recorded in 2011 (cf. 54 AOS in 1995).

 

Productivity

 

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

 

 

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 those 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 2006 found 1,398 AOS2 indicating the English population is relatively stable overall. Changes noted at the major colonies were: Annet and Melledgan declined to 788 AOS and 69 AOS respectively, Round Island increased to 251 AOS and Rosevear increased from 57 to 129 AOS.

 

Productivity

 

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

 

 

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 pairs of European storm-petrel breeding at 6 colonies in Wales. Only one small colony was in found in Gwynedd, on Bardsey, with the other five in Dyfed. By far the most important colony is on Skokholm where 2,450 pairs were estimated to breed. Due to the logistical difficulty in monitoring this nocturnal and burrow-nesting species, little information exists as to population trends. Survey work on a few islands in Dyfed (Bishop and Clerks Islands, Ramsey Island and Grassholm) in 2010 found 159 AOS compared to 210 AOS during Seabird 2000 indicating a partial decline. The small colony on Grassholm (holding 4 and 3 AOS in 2010 and 2012 respectively) was unknown at the time of Seabird 2000.

 

Productivity

 

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

 

 

This species does not breed in Northern 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 lying on the west coast between counties Kerry and Donegal. Of these, 12 were surveyed but the populations of the others could only be estimated. Surveyed colonies were found to hold 57,110 pairs with another 41,955 pairs estimated for unsurveyed colonies. The most important surveyed colony was Inishtooskert, which held 27,297 pairs. The next largest of the surveyed colonies were on Great Skellig (9,994 pairs), Inishvickillane (6,394 pairs) and Puffin Island (5,177 pairs) with only three other colonies holding 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, little information exists as to population trends and no sizable colonies have been re-surveyed since Seabird 2000.

 

Productivity

 

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

 

 

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

 

This species does not breed in Northern Ireland and no systematic data on the productivity of European storm-petrels in the Republic of Ireland have been submitted to the SMP.

 

Productivity

 

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

 

 

This species does not breed on the Isle of Man.

 

 

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, on Burhou, which lies off the coast of Guernsey. Several more 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 trends.

 

Productivity

 

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

 

 


UK phenology, diet, survival rates

 

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

 


 

References

 

1 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. Seabird 23: 14-24.

 

2 Heaney, V., Lock, L., St Pierre, P. and Brown, A. 2008. Important Bird Areas: Breeding seabirds on the Isles of Scilly. British Birds 101: 418-438.

 


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; Centre for Ecology and Hydrology; Countryside Council for Wales; Department of Agriculture, Fisheries and Forestry (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 Environment Agency; 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.