Harbour seal spatial distribution estimated from Argos satellite telemetry: overcoming positioning errors Jakob Tougaard1,*, Jonas Teilmann1, Svend Tougaard2

Abstract

A limiting factor of satellite telemetry in the context of habitat ase by marine mammals is the low accuracy of the received positions. A novel statistical analysis to overcome the low accuracy was developed in the context of processing data on harbour seals phoca vitulina for the atlas of Danish mammals. Ten harbour seals were caught in the Danish Wadden Sea and tracked with satelite transmitters. The statistical analysis reversed the problem of positioning: Instead of attempting to correctly assign each individual position to a single grid cell, our approach considers the combined probability that at least one position originated in each grid cell. Thus, all satellite-derived positions, including positions of poor precision, can contribute to the evaluation. The method is an alternative to other methods describing spatial use, such as kernel home range, and constitutes a viable approach for inclusion of satellite-derived positional data into spatial modeling of animal distribution and habitat use. © Inter-Research 2008.