Restricted constrictors: Space use and habitat selection of native Burmese pythons in Northeast Thailand

Abstract

Animal movement and resource use are tightly linked. Investigating these links to understand how animals utilize space and select habitats is especially relevant in areas that have been affected by habitat fragmentation and agricultural conversion. We set out to explore the space use and habitat selection of Burmese pythons (Python bivittatus) in a patchy land use matrix dominated by agricultural crops and human settlements. We used radio telemetry to record daily locations of seven Burmese pythons over the course of our study period of approximately 22 months. We created dynamic Brownian Bridge Movement Models (dBBMMs) for all individuals, using occurrence distributions to estimate extent of movements and motion variance to reveal temporal patterns. Then we used integrated step selection functions to determine whether individual movements were associated with particular landscape features (aquatic agriculture, forest, roads, settlements, terrestrial agriculture, water), and whether there were consistent associations at the population level. Our dBBMM estimates suggested that Burmese pythons made use of small areas (98.97 ± 35.42 ha), with low mean individual motion variance characterized by infrequent moves and long periods at a single location. At both the individual and population level, Burmese pythons in the agricultural matrix were associated with aquatic environments. Only one individual showed a strong avoidance for human settlements which is troublesome from a human-wildlife conflict angle, especially as Burmese pythons have been observed entering human settlements and consuming livestock in our study site. Our study is one of the first to contribute to the knowledge of Burmese python ecology in their native range as the majority of studies have focused on invasive populations.

Arboreal aperitifs: Space use and activity of a major songbird nest predator in a tropical Thailand forest

“…This method originally analyzed GPS telemetry data on mammals and birds (Kranstauber et al, 2012). However, more recently VHF telemetry data applications on reptiles have become apparent (Knierim et al, 2019; Silva et al, 2018; Smith et al, 2020). Unlike traditional space use estimators, such as minimum convex polygons (MCP) and kernel density estimators (KDE), dBBMMs simultaneously account for spatial and temporal autocorrelation, GPS uncertainty around each location, and are more robust to irregular sampling intervals.…”