By Rahel Borrmann
British urban gulls are famously sneaky and ingenuous when it comes to exploring new food resources and developing individual foraging strategies. As a consequence, they are well-covered in both media and scientific literature, and their reputation reached me long before I came to the UK for the first time. However, I had not expected to find them breeding everywhere in Liverpool, more abundant here than at the German seaside where I lived previously.
If the gulls were aware of the fact that I was once catching gulls for a living, perhaps they would keep their distance. I enjoyed the sight of them, and felt the breeding pair which occupied the adjacent roof, which I regularly observed from my office window, kept me good company. And while the British herring gulls were calling, rearing their chicks, and loitering around the city well into December, I analysed the individual movement strategies of their German cousins, exploring spatial consistency within and across breeding and nonbreeding seasons.
The herring gulls I study breed in their natural habitat on a small island in northern Germany. I analysed year-round GPS/GSM tracking data of 15 individuals collected between 2016 and 2018. Processing and analysing such large data sets can be quite challenging, and it was with great support and ongoing enthusiasm from Tommy Clay that I could identify spatial patterns throughout the annual cycle.
After characterising over 4,000 foraging trips, there seemed to be a great deal of variation in individual foraging strategies, especially compared to great black-backed gulls (data which formed another chapter of my PhD). Also, we found that individual herring gulls vary more in consistency, with fewer individuals showing high foraging site fidelity throughout the breeding season. During nonbreeding, the majority of individuals migrated fairly short distances, some as far as Denmark and the Netherlands, with some individuals visiting the same sites in consecutive years. However, many also visited the colony during nonbreeding, just like those British gulls on the roofs. If they are not at the colony, then they surely can be found on the intertidal flats, in the North Sea as well as in the Mersey river.
I came to SEGUL after defending my PhD to further develop my skills in data analysis and to broaden my knowledge in seabird ecology. There were plenty of possibilities to exchange ideas and learn about the projects of my colleagues. We had a SEGUL symposium with an impressive number of talks and a great variety of topics covered, as well as regular meetings and a journal club.
I also learnt a lot about British culture – a standout moment was the Christmas party of the Ecology and Marine Biology Group, featuring Secret Santa and paper crowns for everyone. They have the tradition of anonymously writing poems for each other, and I will borrow the last lines from the poem I received to finish this blog:
I came for ERASMUS,
And stayed for the Christmus,
And what a great time I had-mus.