Movement and ranging patterns of a tropical rat (Leopoldamys sabanus) in logged and unlogged rain forests

摘要

Knowledge of how animals move through the environment is important for predicting effects of habitat change on faunal distributions. Logging of tropical rain forests produces habitat changes on multiple scales that may affect movement and habitat use by small mammals. To explore the effects of such habitat changes, we compared movement and ranging patterns of the long-tailed giant rat (Leopoldamys sabanus) in logged and unlogged rain forests in Borneo. On a small scale, movement was quantified using spool-and-line tracks; on a larger scale, movement was quantified via radiotracking. At the small scale, paths (49 tracks of 55.2 m ± 20.7 SD each) were relatively straight, with similar step (straight-line section) length distributions in both forest types. At the larger scale, the rats (16 individuals tracked for 4 nights each, X̄ = 1,443 ± 991 m of movement per night) moved with similar speed through both forest types (mean distance covered per 10-min interval = 32 ± 45 m). Based on telemetry data, mean nightly activity periods for individual rats averaged 485 ±109 min (areas covered = 2,083–9,829 m2), with no statistically significant differences between logged and unlogged forests. The large variability in individual movement parameters was not predicted by sex or forest type, suggesting that the paths taken were most likely responses to the local distribution of resources in a heterogeneous rain-forest environment. We conclude that the logged and unlogged forests did not differ with respect to features that are important to movement and ranging patterns of L. sabanus, suggesting that general differences associated with logging may not predict the effects of this type of disturbance on habitat use by individual species of small mammals.