Compass rafting in a colonial seabird: the unknown role of social information

Key Questions

How are the at-sea decisions and distributions of foraging seabirds influenced by social information exchange? 

Background

Huge advances in miniature biologging technologies have in recent years greatly improved our understanding of individual long distance movement behaviour of pelagic seabirds, and its ecological drivers, helping to inform marine conservation and fisheries policies around the world.  But individual loggers tell only half the story because they have largely failed to sample the role of social information and decision-making in such wide-ranging animals in their natural environment.  In the current project we propose to study this knowledge gap by focussing on the hypothesised phenomenon of “compass rafting” in a colonial seabird, the Manx shearwater, utilising novel drone-surveillance tecnologies developed by the company Animal Dynamics who are CASE sponsors on this proposal. 

Aims of the Project

To understand the role of social information exchange in at-sea foraging patterns, by developing drone-based at-sea surveillance methods for observing nocturnal “rafting” behaviour. 

Project Description

Seabird colonies may function as information centres in which information about widely, patchily, and unpredictably distributed foraging resources is exchanged socially.  However, the scale and function of social information in natural, wild biological systems has been hard to test.  Huge advances in miniature biologging technologies have in recent years greatly improved our understanding of individual long distance movement behaviour, and its ecological drivers, helping to inform marine conservation and fisheries policies around the world.  But individual loggers tell only half the story because they have largely failed to sample the role of social information and decision-making in animals.  In the current project we propose to study this knowledge gap by focussing on the hypothesised phenomenon of “compass rafting” in a colonial seabird, the Manx shearwater, which the Oxford Navigatiom Group has many years field research experience with.  Shearwaters, like many colonial seabirds, form large collections of individuals at sea before and after making landfall, and spectacular though these collections are their function is not well understood.  In one study of rafting in shags (Weimerskirch et al., 2010), individual tracking combined with coastal surveying demonstrated a possible orientation signalling function, with individuals using the “compass rafts” to identify the best foraging routes out from the colony.  We propose to combine individual biotelemetric tracking, visual marking, and innovative drone surveilance to study the use of rafts by outgoing and returning foragers to our Manx shearwater study colony on Skomer island, where OxNav already have very good background understanding of behaviour and a robust study system and infrastucture (the figure opposite shows the positions and sizes of evening rafts observed visually from shore during one recent study on Skomer: courtesy of Cerren Richards from Richards et al., 2019). The proposed project would be available to a successful NERC DTP applicant and would incorporate CASE funding and technical support from Animal Dynamics, and would be supervised by Professor Tim Guilford within the OxNav research group in Oxford’s Department of Zoology. 

Richards C, Padget O, Guilford T, & Bates AE. (2019) “Manx shearwater (Puffinus puffinus) rafting behaviour revealed by GPS tracking and behavioural observations.” PeerJ 7:e7863.  

Weimerskirch H, Bertrand S, Silva J, Marques JC, Goya E. 2010. Use of social information 

in seabirds: compass rafts indicate the heading of food patches. PLOS ONE 

5:e9928 DOI 10.1371/journal.pone.0009928. 

Methods to be used

Combining at-sea drone surveillance, bio-telemetry of free-ranging seabirds, life-history field  study measurements, and machine learning analytical techniques 

Specialised skills required

Good quantitative skills; a resilient capacity for nocturnal fieldwork.

Please contact Professor Tim Guilford on tim.guilford@zoo.ox.ac.uk if you are interested in this project