Old tricks-new opportunities: combining telemetry ellipses and landscape metrics to assess habitat spatial structure

Abstract

Confidence ellipses are areas derived from telemetry data that can be used to assess daily habitat use when integrated with land cover spatial structure. Our goal was to assess the feasibility of using confidence ellipses derived from telemetry data to assess landscape structure. Our objectives were (1) to identify the geometry of confidence ellipses that can be used in landscape level studies; and (2) to quantify landscape structure within confidence ellipses derived from telemetry data. We used Rio Grande wild turkeys (Meleagris gallopavo intermedia) as our model species. We simulated landscapes and clipped them using known confidence ellipse shapes. We then compared the clipped areas with values measured for our simulated landscapes using landscape metrics that describe landscape structure. We used these results to select ellipse derived from telemetry data to evaluate landscape structure used by wild turkeys during the breeding and wintering seasons in South Texas. Ellipses with a low x/y ratio (< 0.38) had significant differences from simulated landscape measurements. This information was used to remove wild turkey ellipses that did not meet the simulation criteria. Our results suggest that wild turkeys in South Texas used larger, more aggregated and interconnected patches of woody cover during the wintering season than during the breeding season. Landscape simulations facilitate the understanding of how landscape sampling strategies may be affected by sampling shape models. The integration of wildlife telemetry data with landscape ecology approaches and remote sensing were important in identifying spatial patterns used by wildlife.