Seabird numbers and breeding success in Britain and Ireland, 2003
UK nature conservation, No.28
Mavor, R.A., Parsons, M., Heubeck, M., Pickerell, G. & Schmitt, S.
Annual reports on JNCC's Seabird Monitoring Programme, summarising the present state of seabird populations within Britain and Ireland - 2003 edition.


This report presents the results of monitoring of seabird populations and breeding performance throughout Britain and Ireland in 2003 and makes comparisons with previous years. The report is produced annually as part of the JNCC's Seabird Monitoring Programme, in collaboration with the Royal Society for the Protection of Birds (RSPB) and the Shetland Oil Terminal Environmental Advisory Group (SOTEAG). Some findings of particular note in 2003 are summarised below:
  • Fewer red-throated divers nested in Shetland in 2003 than in 2002 and did so later, possibly due to Image of Seabird numbers and breeding success in Britain and Ireland, 2003 coverfood shortages early in the season, but those that nested were quite successful. In Orkney breeding numbers were similar to 2002 and success was above average at all sites.


  • A survey of Leach's storm petrels on Dun, St Kilda, revealed an apparent 48% decline in breeding numbers since it was last surveyed, in 1999, when it held 27,700 AOS to just 14,417 AOS in 2003. Predation of petrels by great skuas, whose population on St Kilda has increased dramatically, is known to be intense and the interactions between these two species is the subject of current research.


  • Two new breeding colonies of northern gannet were established in 2003, in Orkney: at Sule Skerry and at Noup Head, Westray.


  • Large increases in the breeding number of European shags were recorded in SE Scotland and NE England between 2002 and 2003, where numbers are now beginning to return to levels recorded prior to the 'wreck' in 1994. Long-term declines continue in NW Scotland and Shetland.


  • Overall, the population of Arctic skuas decreased by c.15% compared with 2002, to its lowest level since 1989. The decline was highest on Shetland, where many sites had their least productive year on record, caused by a severe lack of sandeels. Breeding numbers of great skuas were generally more stable, although breeding success was very low in Shetland.


  • Many of the larger breeding colonies of lesser black-backed gulls declined between 2002 and 2003. Numbers on Skomer and Skokholm were the lowest during the history of the SMP and numbers declined at major colonies in NW England, including S. Walney and Rockcliffe Marsh.


  • The long term decline in breeding numbers of black-legged kittiwake continued in 2003 in Shetland, SE Scotland and SE England. The population on Orkney appears to have stabilised, following declines during the 1990s. Near breeding failure occurred in Shetland. Productivity was higher in Orkney but well below 2002 levels.


  • Numbers of roseate terns reached their highest level since 1979, largely attributable to an increase on Rockabill (SE Ireland). However, fewer sites reported breeding than in any year since 1969. The 2003 breeding season was the most productive for 11 years.


  • Numbers of common guillemots generally decreased between 2002 and 2003, particularly so in Shetland, also in Orkney between 2000 and 2003. Increases occurred in SE Scotland (whole colony counts only), NE England and in Irish Sea colonies. Productivity generally declined between 2002 and 2003, reaching its lowest ever level in Shetland; some colonies in Orkney were similarly unproductive.


  • Large increases in breeding numbers of Atlantic puffin were noted in some of the larger colonies in SE Scotland and NE England, but declines also occurred in these regions. Many of the monitored colonies in the west of Britain decreased. Breeding success was higher than the long-term average in 2003.


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For further information please contact:
Joint Nature Conservation Committee, Dunnet House, 7 Thistle Place, Aberdeen, AB10 1UZ
ISBN 1 86107 564 2
Please cite as: Mavor, R.A., Parsons, M., Heubeck, M., Pickerell, G. & Schmitt, S., (2004), Seabird numbers and breeding success in Britain and Ireland, 2003, ISBN 1 86107 564 2