The cliffs and seas around Orkney are nationally important for a range of seabirds, but unfortunately seabirds in the UK have generally been having a difficult time of it in recent years, with a host of increasing pressures on them. Around the coasts of the UK, these include the effects of climate change on their food supply, activities associated with some fishing practices (such as overfishing of seabird prey and seabirds being accidentally caught in fishing gear), pollution of the seas, and the impacts of marine planning leading to developments in some sensitive seabird areas. To understand how seabird populations are changing, a national census of all the breeding seabirds in the UK is carried out every 15 years or so, a vast undertaking when you consider the number of colonies and the remoteness of some of them!
The current national survey is called Seabirds Count, and the RSPB Orkney team have been out and about surveying seabirds all over Orkney over the last few years as part of the census. In 2018, we focused on counting terns, gulls and skuas, and we also carried out a full census of the colony at Marwick Head, the largest seabird colony on Mainland Orkney. This was no mean feat, particularly when you are counting thousands of guillemots along huge sections of cliffs – you really don’t want to lose your place when you’re part way through counting! When surveying such large numbers, we usually try to get two people counting the same section and species at the same time, and count and count again until we make sure that both people are getting similar numbers, to be sure we haven’t missed or double-counted any areas, and it can take a few goes sometimes to get it right.
Counting seabirds at Marwick Head - Alan Leitch
When compared to the figures from the Seabird 2000 count (actually carried out in 1999), the final numbers for Marwick Head make for fairly disheartening reading, with a massive decrease of 84% in the size of the kittiwake colony, and we have lost two thirds of our guillemots over the last two decades.
These sort of drops of numbers are seen quite starkly when the same areas of cliff are compared between years:
Marwick plot 1980
Same plot 2013
RSPB has been working hard to find out what is causing these declines. We carry out studies on productivity (how many young fledge from each nest) on a range of seabirds at Marwick Head each year, as this can give us an indication of whether adult birds are finding enough food to bring back to feed their young, and in many years over the last few decades this has been very low. Last year, studies on our kittiwake plots at Marwick Head by JNCC showed that an average of only 0.3 young were successfully fledged from each nest, way too few to keep numbers up in the population. Studies using tracking technology on Orkney, where a small GPS tag is temporarily attached to the seabird’s back to follow their movements, have also been used in past years to show that seabirds are having to travel in some cases hundreds of miles to find a single meal for their young. This suggests that difficulties in finding food are at least part of the problem.
So, the future for seabirds in Orkney looks to be difficult. However, RSPB is doing what we can in terms of research to better understand the problem, and the figures from all our surveys will be part of the data used to back up policy and advocacy work to lobby for better protection of areas that seabirds use for breeding and feeding, and for pressure to keep to climate change commitments. There was also a little bit of good news in the counts – although down in number compared to 1999, numbers of razorbills, fulmars and guillemots at Marwick Head had increased a little since our last count in 2015, and we hope that this trend may continue.
There are also ways in which you can help, if you would like to be more involved. Seabirds Count has another year at least to run, and there are still lots of areas to be surveyed both in Orkney and all over the country. If you would like to help out as a volunteer surveyor, then you can find out more about the survey and how to register at http://jncc.defra.gov.uk/page-7413
Thanks Alex and glad you are enjoyed the content of the seabird blog.
This is yet another excellent post demonstrating the important work being undertaken by RSPB staff and volunteers all over the uk.