Masters Project 2017
Post date: Nov 29, 2017 5:28:52 PM
My name is Will Bevan, and I have just completed a Master’s degree in Conservation and Resource Management at the University of Liverpool. As part of my degree I had to develop a research project which would contribute to a large chunk of my final grade. Having been fascinated by seabirds for a long time but never being able to get any experience working with them, I jumped at the chance to work on Puffin Island, signing myself up for a project looking at what factors were influencing the ecology of the European shag (Phalacrocorax aristotelis) population on the island. Although the breeding season is now over, this post is a summary of my fieldwork and other monitoring activities I took part in over the spring and summer this year, as well as the findings of my research project.
Our first trip out took place on a grey day in early April, with my supervisor Jon Green and another master’s student Joe Hanlon. This was mostly a day to become familiar with the island and to see how the birds were faring, with some of the birds having already begun to lay eggs. I was instantly enthralled with the island, having never worked in a seabird colony before, and was more than a little trigger happy with my camera that day. I couldn’t wait to return.
Coming back in early May, the breeding season was already well under way for some of the birds, and I began to monitor the nests of shag pairs as part of the productivity monitoring which has been conducted by the Seabird Ecology Group at the University of Liverpool (SEGUL) since they started working on the island in 2010. This involved visiting nests in three distinct plots; named the ledge, main and beach plots, and counting the number of chicks and eggs in each nest every time I visited the island until the chicks had fledged or the nests failed. From working out the mean number of chicks which fledged per nest over the breeding season, an estimate of productivity for the population on Puffin Island could be determined for this year. This is useful because it can help us see how productivity is changing from year to year, and so we can determine what factors in any given year might be influencing it. We can also use information on productivity to create accurate population models which can predict changes in the size of the population on the island.
In late May a number of us from SEGUL and others from different agencies and organisations helped conduct a survey of the gulls on the island, which had not been undertaken since 2014. Over the course of three glorious but unrelentngly hot days (especially as there is nowhere to take shelter on the island), we counted 1105 nests, and all three species; herring, lesser black-backed and greater black-backed, had increased in numbers.
Another aspect of my project involved looking at how the number of shags had changed on the island since the first count of the population in 1979. Whilst I used counts taken by Natural Resources Wales for this, a complete census of the shags on the island had not been undertaken since 2010, and so over two days in mid-June I went along with the SCAN ringing group to count shag nests as they tried to ring adult and juvenile shags and razorbills, and inaccessible nests were counted by boat. I was also able to ring a few of the birds myself, an opportunity I had not had before, and was invited back to help on another day of ringing, this time primarily for guillemots and cormorants. These days were exhausting and slightly nerve wracking, whether perching on the edge of the cliffs with a bag full of guillemot chicks ready to be ringed tied to my arm, or herding skittish cormorant chicks up the steep slopes on the other side of the island. The days were exhilarating though and it was great to see the SCAN team at work; I was even able to ring a puffin!
My research back in Liverpool mostly involved bringing together previously collected data on productivity and population numbers from Puffin Island and seeing how these had changed over time, as well as whether changes in productivity could be linked to inter-annual variations in environmental conditions. I also used tracking data collected for
a previous study to identify core feeding areas used by the shags in the sea surrounding the island. I found that the number of breeding pairs has been increasing on the island over time, in addition to productivity. This suggests that the Puffin Island colony is becoming more established, compared to some places in the UK where numbers have fallen dramatically in recent years, and this is also the national trend for shags. In order to fully protect the shags on Puffin Island, which is itself a Special Protected Area (SPA), this area should be extended to include marine areas used by the birds.
When fieldwork was virtually at an end for the season, we returned one last time to the island in mid-July to collect a camera which had been monitoring kittiwakes. To our surprise in the main shag plot around 40-50 puffins were perched on the cliffs, the most we had seen at any one time in the season. It may have been that with the shags having good year and their chicks fledging relatively early on, ledges were freed up where the puffins could lay eggs. It was a fitting end to my fieldwork and I hope that my research will help further understanding of the European shag population on Puffin Island.
