Leach's Petrel

Hydrobates leucorhous (Vieillot, 1818) TL LEAPE 550
Family: Procellariiformes > Hydrobatidae

Leachs Petrel, Yoav Perlman

This is the most marine of our breeding birds and a difficult species to see, visiting its underground nests at night and spending the rest of the time at sea.

Leach's Petrel has a more restricted breeding distribution within Britain & Ireland than the more familiar Storm Petrel, its colonies all located within 70 km of the Atlantic continental shelf. While significant numbers breed at colonies on remote islands far off the coasts of Scotland and Ireland, our population is small compared to those off North America.

As with other burrow-nesting seabirds, the species faces a threat from mammalian predators inadvertently introduced to islands. Leach's Petrels may also be taken by avian predators, which is one reason for their nocturnal habits at breeding sites.


Leach's Petrel identification is sometimes difficult. The following article may help when identifying Leach's Petrel.

related video

Identifying Petrels

Storm Petrel. Photograph by Joe Pender

Petrels are seldom-seen, unfamiliar birds to many of us, but both species: Storm Petrel and Leach's Petrel are actually very common breeding birds and frequently encountered off our shores during passage. Both are small black and white birds that seem to defy the rough seas they are often encountered in. How can we tell the two species apart?


Listen to example recordings of the main vocalisations of Leach's Petrel, provided by xeno-canto contributors.

Alarm call


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Status and Trends

Population size and trends and patterns of distribution based on BTO surveys and atlases with data collected by BTO volunteers.


This species can be found on the following statutory and conservation listings and schedules.



This species nests in burrows and is difficult to survey and the first full Census was carried out during the 1998–2002 Census (Seabird 2000) using tape-playback techniques. Subsequent surveys at two UK colonies suggest that declines have occurred, included a 54% decline at the largest UK colony at Dun (St Kilda), which held around 58% of the UK population at the time of the Seabird 2000 surveys.


Leach's Petrel colonies are limited to remote, offshore islands in the far north and west of Scotland and Ireland, close to the deep-water areas beyond the continental shelf where they are thought to feed. Outside the breeding season they can sometimes be seen from coastal headlands and seawatching hotspots during autumn and early winter gales.

Occupied 10-km squares in UK


Change in occupied 10-km squares in the UK


Leach's Petrel is a very localised breeder, though is rarely seen during the breeding season. Most records are in autumn and come from storm-blown individuals on the coast and occasionally inland.

Weekly occurence of Leach's Petrel from BirdTrack
Weekly occurrence patterns (shaded cells) and reporting rates (vertical bars) based on BirdTrack data. Reporting rates give the likelihood of encountering the species each week.


Information about movement and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.


View a summary of recoveries in the Online Ringing Report.

Foreign locations of birds ringed or recovered in Britain & Ireland

Foreign locations of Leach's Petrel ringed or recovered in Britain & Ireland
Encountered in: Winter (Nov-Feb); Spring (Mar-Apr); Summer (May-Jul); Autumn (Aug-Oct)


Lifecycle and body size information about Leach's Petrel, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.



View number ringed each year in the Online Ringing Report



For information in another language (where available) click on a linked name

Gaelic: Gobhlan-mara
Welsh: Pedryn Drycin Leach
Catalan: ocell de tempesta boreal
Czech: burnácek dlouhokrídlý
Danish: Stor Stormsvale
Dutch: Vaal Stormvogeltje
Estonian: põhja-tormipääsu
Finnish: myrskykeiju
French: Océanite cul-blanc
German: Wellenläufer
Hungarian: villás viharfecske
Icelandic: Sjósvala
Irish: Guairdeall Gabhlach
Italian: Uccello delle tempeste codaforcuta
Latvian: ziemelu vetrasburatajs, cice
Lithuanian: šiaurinis audrašauklis
Norwegian: Stormsvale
Polish: nawalnik duzy
Portuguese: painho-de-cauda-furcada
Slovak: víchrovnícek severský
Slovenian: viharni strakoš
Spanish: Paíño boreal
Swedish: klykstjärtad stormsvala


Interpretation and scientific publications about Leach's Petrel from BTO scientists.


Causes of change

The causes of change are unclear and the extent of the suspected decline is uncertain until the full results of the Seabirds Count (2015–2021) are published. However, predation (by Great Skuas and Great Black-backed Gulls) has been suggested as one possible cause of decline (REF FROM JNCC WEBSITE). Other factors could be contributing to decline and further investigation is needed.

Links to more information from ConservationEvidence.com

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