Understanding processes of animal distribution and habitat choice: application of Wireless Sensor Networks to wildlife studies

Biologging, and especially those systems providing automated collection of animals’ positions, has certainly revolutionised the way to study animals in their environment, moving the observation point to animals themselves. However, the opportunity to integrate knowledge on animal movement with information gathered from the environment, has been largely overlooked so far, especially in terrestrial systems, where animal-borne data and environmental indexes are often collected in separate steps. Inferences on how habitat variables affect animal behaviour are therefore derived from post-hoc modelling, where animal activity, presence or distribution are modelled against a series of habitat variables. While this approach allowed to describe habitats of importance for species, it often failed to ascertain the processes at the basis of habitat choice and animal distribution in the environment. We propose the application of wireless sensor networks (WSNs) technology to terrestrial systems to design and effectively undertake hypothesis-based field experiment on habitat use. WSNs devices are equipped with a low-power microcontroller unit (MCU) enabling on-board computation, a wireless communication interface, storage memory, and a set of sensors. Thanks to this instrumentation and appropriate software control, the perspective to study habitat effects on individuals is totally reversed: when certain environmental conditions apply (e.g., temperature range, proximity to key resources, proximity among individuals), the device is activated to acquire an intense set of animal-borne and other data, thus providing a robust and quantitative basis for hypothesis validation. We present the results of simulation tests in challenging environments (e.g., tropical cloud forest, thick broad-leaved alpine forest), and discuss the potential of this system to study critical interaction between animal and resources (e.g., winter habitat use of ungulates in the Alps; proximity of zoonotic urban foxes to human settlements)