[Rd] [SoC09-Idea] Movement Ecology add-ons for adehabitat package

From: Damiano G. Preatoni <prea_at_uninsubria.it>
Date: Tue, 24 Feb 2009 15:34:55 +0100

Hi all,
  here's a proposal for a SoC project on wildlife movement patterns analysis. A MSc student is available to anwser the call, of course. The idea has already been briefly discussed with the mantainer of the adehabitat package and the AniMov project community.

Short description
Develop some add-on functions to use the adehabitat package to perform basic movement ecology analysis, in particular analysis of fractal dimension D. Developed functions could possibly be included in a future release of the adehabitat package itself.

Detailed description
Fractal dimension analysis is an useful tool to better understand not just the 'path tortuosity', in an animal's trajectory, but also the scale level at which 'search patterns' occur, i.e. an indirect index of the scale at which habtat resources are 'perceived'.
It has already been shown using simulations (Nams 2005; Oecologia 143: 179-188) that the fractal dimension D of a trajectory changes within scales, and that the fractal dimension could be a valuable tool in multiscale analysis of wildlife movement patterns.
The adehabitat package, increasingly used as a free-open source alternative in radiiotracking and animal habitat selection studies, already has base functions to deal with trajectories in time and space, both as regular samples (e.g. data from GPS radio tags) and as irregular ones (as in 'classic' VHF radiotraking). The implementation of the algorithms devised by Nams could widen the range of analytical instruments that already make adehabitat an almost complete tool.
Moreover, the author of the sole existing software to do fractal analysis (V. O. Nams [0]) has expressed no objection towards such a porting (as reported by Paolo Cavallini in the AniMov mailing list [1]), suggesting that a complete rewrite could be a better solution. In detail, the project objectives will be to port (or rewrite) into R the 'standard' methods offered by the FRACTAL program:
- fractal dimension estimation (D) using the basic divider method

Required skills
The candidate should be both familiar with R programming and wildlife radiotracking data analysis. A minimal familiarity with the adehabitat code could be desirable.

Damiano G. Preatoni, PhD.
Research Associate
Unità di Analisi e Gestione delle Risorse Ambientali Dipartimento Ambiente-Salute-Sicurezza
Università degli Studi dell'Insubria
(see signature for details)

And, finally, the programming exercise [2]: the candidate should demonstrate to be able to transform raw irregular VHF radiotracking data into an adehabitat ltraj object, which could be the base data structure to work with in the proposed package.

[0] http://nsac.ca/envsci/staff/vnams/Fractal.htm
[1] http://www.nabble.com/fractals-to21875728.html
[2] http://xkcd.com/74/


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Received on Tue 24 Feb 2009 - 13:41:38 GMT

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