Tuesday 19 August 2014

After busily deploying data loggers on white storks, what is happening to all that GPS location data?

Training the model with manually classified behaviours. The graphs on the left shows bird movement on 3 axes, plus speed, the graph on the right plots the track of GPS coordinates associated with the behaviour. In this sequence the bird is foraging. The head is going up and down (dark top line) as it walks along (denoted by the wavy movement in the bottom grey line). The speed line (circles and dashes) shows stop and start movement, and this is reflected in the change in position from the GPS coordinates.
Despite my resolve to write more frequent posts somehow months have slipped by!

All my fieldwork is finished and finally last week I finished my lab work in the stable isotope laboratory, both sad moments. With a complete data set now in front of me this means a serious switch to the next phase of my PhD: the data analysis and writing up (via preparing for oral presentations at 2 conferences coming up in September).

So after busily deploying all those data loggers on white storks, what is happening to that GPS location data?

Well, whilst plotting the GPS data to investigate landfill and non-landfill habitat use, home territories and preferred habitats, I am also investigating the behaviour of the birds during each GPS fix. Every transmission the loggers were also quietly collecting data about how the bird was moving, therefore what it was likely doing. From this I can tell for each location if the bird was head up or down, rolling movement from side to side, and also up and down through vertical space. Such amazing technology! Flicking through the graphs is like opening a window onto a secret world.
There are literally thousands of graphs for each bird so at the moment I am busy classifying behaviour by eye to train a model to classify the behaviours for me. I confess I am quite addicted to looking at the graphs so what sounds like a boring task really isn't. The photo above is a screen shot of this process.

These data will be presented at the 5th Bio-Logging Science Symposium in Strasbourg at the end of September (bls5.sciencesconf.org/).

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