Is a Handheld GPS Enough for Research in Ecology? A Case Study of Handheld versus RTK Technology on the Interpretation of Behavioral Ecology Data

摘要

The distribution and dispersal patterns of organisms are of great interest to ecologists. The handheld global positioning system (GPS) is the tool of choice for ecologists for collection of spatial data; however, the accuracy of these devices can limit their facility for determining accurate dispersal patterns of small species in complex landscapes. In addition, animals move in a three-dimensional space. Vertical movements or movement in response to changes in elevation would not be captured using a typical latitude-longitude coordinate system with a handheld GPS. Thus, conclusions that are drawn based on handheld GPS data may be different from those using more precise, three-dimensional real-time kinematic (RTK) GPS survey technology. This technology is a novel approach to behavioral ecology research. In this study, we explored the usefulness of RTK GPS technology for the study of the dispersal patterns in a small animal, the eastern fence lizard (Sceloporus undulatus). We used the mark-recapture method to estimate the distances moved by juvenile lizards over short time periods and compared the scale of these movements with the accuracies of handheld and RTK GPS. All lizards were released at the same location and recaptured every 2 weeks with notation of their capture location. We used a handheld GPS to record lizard location data as a part of an undergraduate field biology course. Lizards moved short distances within the horizontal accuracy of the handheld GPS, which suggests that this technology is insufficient for analysis of lizard movements. There is a need for more precise tracking technology for behavioral ecology research, and for collaboration between surveying engineers and ecologists.