ON THE USE OF UNMANNED AERIAL VEHICLES TO RAPIDLY ASSESS MICROHABITATS OF TWO TEXAS LIZARD SPECIES, COPHOSAURUS TEXANUS AND ASPIDOSCELIS GULARIS

We examined the effectiveness of using an unmanned aerial vehicle (UAV) as a tool for the rapid assessment of microhabitat in Texas spotted whiptail (Aspidoscelis gularis) and greater earless lizard (Cophosaurus texanus). We collected microhabitat data from aerial images captured at lizard sightings along gravel roadways on Devils River State Natural Area – Big Satan Unit (DRSNA-BSU) from July through September, 2014. Point locations of lizard sightings were also compared with DRSNA-BSU environmental maps including: soil type, vegetation type, Normalized Difference Vegetation Index (NDVI), elevation, and slope. Multiresponse Permutation Procedures (MRPP) and Permutational Multiple Analysis of Variance (PerMANOVA) analyses indicated that the spatial distributions of the two lizard species were significantly different. Non-metric Multidimensional Scaling (NMDS) analyses revealed that grasslands, low slopes, and soft soils were correlated with the presence of A. gularis while steep slopes, rocky soils, and the xeric plants lechuguilla, sotol, and guajillo were associated with the presence of C. texanus. Our data are consistent with other habitat association analyses administered on these two lizards. UAVs provided a new perspective on the study of microhabitat and we recommend them as a method of rapid habitat assessment. Data collection for one individual lizard in the field could be completed in less than three minutes with the use of our UAV, making the technology an ideal technique for gathering habitat data in a short amount of time.