Biomathematics & Statistics Scotland
Many species of seabird are in decline, and seabird populations are under threat from a range of different sources. In order to understand the nature and magnitude of these threats, and to conserve seabird species, it is important to understand patterns of movement and behaviour. Such studies allow us to identify the spatial locations and environmental conditions that are associated with foraging and other key activities.
Seabirds spend much time at sea, and frequently nest in inaccessible locations, so it is difficult to collect direct data on their behaviour and distribution. Electronic tagging data provide an exciting, and rapidly developing, source of data. This project will be concerned with using data from two types of electronic tag - GPS tags and TDR tags - to draw statistical inferences about the behavioural characteristics of seabirds and about their spatial distribution around the coast of the British Isles. GPS tags provide information on spatial location (and therefore, indirectly, on speed and direction), whilst TDR tags provide information on depth and temperature during periods in which the bird has dived below the water surface.
A range of different statistical approaches will be explored, including generalized linear mixed models and generalized additive mixed models (Aarts et al., 2008), but the project is likely to focus primarily upon multi-state random walk model and state space models (Patterson et al., 2008). The final choice of modeling approach is likely to vary between species, since different species are known to exhibit substantially different patterns of movement and behaviour. The project will focus on the integration of multiple data sources (GPS tags, TDR tags, and other data, such as ship-based surveys, which are not based on electronic tagging) into a unified statistical analysis, and on combining information across colonies.
For further details, contact Adam Butler
Aarts, G., MacKenzie, M., McConnell, B., Fedak, M. and Matthiopoulos, J. (2008) Estimating space-use and habitat preference from wildlife telemetry data. Ecography, 31, 140-160.
Patterson, T.A., Thomas, L., Wilcox, C., Ovaskainen, O. and Matthiopoulos, J. (2008) State-space models of individual animal movement. Trends in Ecology and Evolution, 23(2), 87-94.
