Using individual movement data and environmental variables to understand breeding seabird movement behaviour.

Seabirds are a diverse group of nearly 350 species, occupying a range of habitats from the poles to the tropics. They are also one of the most globally threatened vertebrate groups. In addition to their use as ocean indicator species, seabirds play a key role in marine ecosystem functioning, as well as nutrient transfer from pelagic to coastal areas. To effectively protect these vulnerable species, it is critical to identify, conserve and manage their key habitats. Using a combination of GPS tracking, behavioural modelling and remotely sensed environmental variables, researchers can investigate the drivers and spatial extent of seabird habitat use. Hence, these represent key tools for conservation planning. The overall aim of this thesis was to systematically review the application of these methods in seabird research and to develop novel methods for integrating information on seabird behaviours into the identification of key seabird habitats for marine spatial planning. This thesis focuses on the at-sea movement behaviour of a vulnerable (IUCN Red List) seabird species, the black-legged kittiwake, Rissa tridactyla. I utilise GPS tracking data from breeding individuals, at 15 colonies around the UK and Ireland between 2010 and 2015. This dataset includes a total of 1955 foraging trips made by 586 individuals. Overall, the work presented in this thesis provides novel insights into the use of remote sensing and analytical tools to identify and characterise seabird habitat, with consequences for marine spatial planning. Additionally, it provides new information on the behavioural landscapes of kittiwakes in the UK and Ireland. The novel methods developed and new ecological insights and will contribute to the future monitoring, management, and conservation of these important and threatened marine predators.