TY  - JOUR
AU  - Dragon AC, Bar-Hen A.
PY  - 2012//
TI  - Comparative analysis of methods for inferring successful foraging areas from Argos and GPS tracking data
T2  - 0171-8630
JO  - Mar Ecol Prog Ser
SP  - 253
EP  - 267
VL  - 452
KW  - Area-restricted-search · Drift dive · First bottom time · Mirounga leonine · Movement analysis · State-space modelling
N2  - Identifying animals’ successful foraging areas is a major challenge, but  such comprehensive knowledge is needed for the management and conservation of wild populations. In recent decades, numerous specific analytic methods have been developed to handle tracking data and to identify preferred foraging areas. In this study, we assessed the efficiency of different track-based methods on Argos and GPS predators’ tracks. We investigated (1) the consistency in the detection of foraging areas between track-based methods applied to 2 tracking data resolutions and (2) the similarity of foraging behaviour identification between track-based methods and an independent index of foraging success. We focused on methods that are commonly used in the literature: empirical descriptors of foraging effort, Hidden Markov Models (HMMs) and first passage time analysis. We applied these methods to satellite tracking data collected on 6 long-ranging elephant seals equipped with both Argos and GPS tags. Seals were also equipped with time depth recorder loggers from which we estimated an independent index, based on the drift rate and the changes in the seals’ body condition, as a proxy for foraging success along the tracks. Favourable foraging zones identified by track-based methods were compared to locations where the body condition of the seals significantly increased. With or without an environmental covariate, HMMs were the most reliable for identifying successful foraging areas on both high (GPS) and low (Argos) resolution data. Areas identified by HMMs as intensively used were congruent with the locations where seals significantly increased their body condition given a 4 d metabolisation lag.
SN  - 0171-8630
UR  - http://dx.doi.org/10.3354/meps09618
N1  - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=3872), last updated on Tue, 09 Jul 2024 01:41:24 +0200
ID  - DragonAC2012
ER  -