Using GPS to remotely observe wildlife behavior

GPS plays an important role in wildlife conservation by enabling managers to track the movements of animals and figure out important information like population home ranges and migration routes. But sometimes wildlife biologists want to know more than just where an animal is located - sometimes they also want to know what an animal is actually doing.

In a new study, researchers from Germany and the Czech Republic have tested a method for expanding the capability of GPS into a tool for remotely observing animal behavior in the field.

The method involves calibrating GPS for a given species by recording fine scale movements of animals along an x-y axis to come up with signature values for specific behaviors. Once the GPS is calibrated for a species, it can then be used to detect behavior in the field.

Petra Löttker and fellow researchers tested the method on red deer in Germany and published their findings in the journal Wildlife Biology. The approach can help wildlife biologists better understand species habitat use and detect deviations from normal animal behavior.

Typically, to obtain this type of information, scientists might have to rely on direct observation - a method that can be expensive, invasive, and very difficult to successfully conduct on elusive, far ranging species. 

The researchers developed their method on red deer by outfitting individuals with GPS collars equipped with dual-axis acceleration sensors that continuously deliver x- and y-values on a scale from 0 to 255.

They maintained the animals in a 2-ha enclosure and recorded their behaviors over the course of many hours of observation. They then used statistical analysis to match up x-y values with specific behavioral categories and come up with threshold values that signify activities such as feeding, resting, and moving.

They found that the threshold values were fairly accurate in signifying a given animal behavior, although sometimes errors occurred. For example, the animals would sometimes shake their bodies during resting giving a false value for feeding.

These types of errors would likely be greater for species that are more easily excited and vigilant. The researchers also concede that animal behavioral movements might be somewhat different in a field environment than an enclosed setting.

Despite these potential shortcomings, though, this methodology appears to hold promise in helping wildlife biologists use the new generation of GPS devices to remotely observe wildlife behavior (and location).

--Reviewed by Rob Goldstein

Löttker, P., Rummel, A., Traube, M., Stache, A., Šustr, P., Müller, J., & Heurich, M. (2009). New Possibilities of Observing Animal Behaviour from a Distance Using Activity Sensors in Gps-Collars: An Attempt to Calibrate Remotely Collected Activity Data with Direct Behavioural Observations in Red Deer Wildlife Biology, 15 (4), 425-434 DOI: 10.2981/08-014