Sandhopper orientation integrates environmental information. Preliminary considerations on the case-study of Laou River moputh, Morocco

Experiments on sandhopper orientation were carried out in Oued Laou, northern Morocco, on the two river banks, two km far each other, at the same time. Nevertheless, the behaviour of the two populations tested was found to be very different, considering both the orientation mechanisms used and the precision of the directional choices. Environmental characteristics were analysed at the two river sides, including human impact: major differences emerged in human use of the two beaches, with effects on the exploitation of beach resource. The different impacts may explain the observed differences in sandhoppers behaviour. This study highlights once again the necessity of an integration of the different compartments of knowledge, to understand of a complex system. The orientation behaviour of sandhoppers is potentially a good early warning indicator, as it is extremely sensitive and linked with many environmental features. However, in order to use it as a tool for monitoring impacts, the temporal and spatial scales of analysis must be defined.