GPS tags have revolutionised the field of wildlife spatial ecology by providing a large number of animal location datapoints at a very fine spatial scale. Although GPS tags have been used on large animals for several decades, it is only recently that technological advances have allowed lightweight GPS tags to be deployed on small animals with limited travel distances. Importantly, factors such as canopy cover, topography, and tag orientation can affect the ability of GPS tags to obtain satellite fixes, which can subsequently affect the accuracy of recorded locations.

If not corrected for, biases in location data obtained from GPS tags could lead to erroneous inferences regarding animals’ habitat use, home-range sizes, and movement paths, which could reduce the effectiveness of conservation efforts based on such inferences.

Here, we used a double-sampling method (i.e. GPS tags and ground-truthing with radio-telemetry) and quantified the effects of habitat characteristics and data screening on the accuracy of location data obtained from GPS tags deployed both in stationary tests and on wild eastern box turtles and spotted turtles, which co-occur at our study sites but use different habitat types.

We found that canopy cover reduced both the number and accuracy of locations obtained from GPS tags, that dense ground vegetation decreased the fix success rate of GPS tags, and that GPS tags were ineffective when submerged underwater. We further showed that using a simple method to screen data and exclude low-accuracy locations is essential if locations obtained from GPS tags are used to make inferences about a species’ habitat use or spatial ecology.

Screening data to reduce location error is particularly important for animals with small home-range sizes and short travel distances because a small number of erroneous locations can introduce substantial bias in inferences regarding a species’ space use.

We encourage researchers to report measures of error (i.e. location error, horizontal dilution of precision, number of satellites received) for GPS location data and to employ data-screening methods to exclude low-accuracy locations and improve the reliability of published animal location data, and the inference drawn there from.

GPS 标签通过在非常精细的空间尺度上提供大量动物位置数据点，彻底改变了野生动物空间生态学领域。尽管 GPS 标签在大型动物身上使用已有数十年，但直到最近，技术进步才允许将轻型 GPS 标签部署在行进距离有限的小型动物上。重要的是，冠层覆盖、地形和标签方向等因素可能会影响 GPS 标签获取卫星定位的能力，从而影响记录位置的准确性。

如果不加以纠正，从 GPS 标签获得的位置数据的偏差可能会导致对动物栖息地用途、活动范围大小和移动路径的错误推断，从而降低基于此类推断的保护工作的有效性。

在这里，我们使用了双采样方法（即 GPS 标签和无线电遥测地面实况），并量化了栖息地特征和数据筛选对从静态测试和野外部署的 GPS 标签获得的位置数据准确性的影响。东部闭壳龟和斑点龟在我们的研究地点同时出现，但使用不同的栖息地类型。

我们发现，树冠覆盖降低了 GPS 标签获取位置的数量和准确性，茂密的地面植被降低了 GPS 标签的定位成功率，并且 GPS 标签在水下时无效。我们进一步表明，如果使用从 GPS 标签获得的位置来推断物种的栖息地利用或空间生态，则使用简单的方法来筛选数据并排除低精度位置至关重要。

筛选数据以减少定位误差对于活动范围较小和旅行距离较短的动物尤其重要，因为少量的错误位置可能会在有关物种空间利用的推论中引入重大偏差。

我们鼓励研究人员报告GPS定位数据的误差测量（即定位误差、水平精度衰减、接收到的卫星数量），并采用数据筛选方法排除低精度位置并提高已发布动物定位数据的可靠性，以及从中得出的推论。