Influence of microhabitat structure and disturbance on detection of native and non-native murids in logged and unlogged forests of northern Borneo

Abstract

Abstract:Understanding the habitat preferences of native and non-native species may offer valuable insights into the mechanisms favouring invasion of disturbed habitats. This study investigated the determinants of trap-site detection probability of three native (Maxomys surifer, Maxomys whiteheadi and Leopoldamys sabanus) and one invasive (Rattus rattus) species of terrestrial murid (Muridae) in logged and unlogged forests of northern Borneo. We established four and two trapping grids in repeatedly logged and unlogged forest, respectively, for a total of 500 sampled trap sites. From these, we obtained 504 detections of the four species over 3420 trap nights. For each species, probability of detection was modelled as a function of both the structural components and disturbance level of the forest patch measured around each trap site. Each of the four species showed contrasting microhabitat preferences: M. surifer favoured increased canopy closure and intermediate ground and understorey vegetation cover; M. whiteheadi preferred increased ground vegetation cover and canopy height; L. sabanus favoured sites with larger amounts of coarse woody debris and less leaf litter; and R. rattus was associated with increased ground vegetation cover. Within logged forest, detection probabilities of the three native species did not vary significantly with level of patch disturbance, whereas that of the invasive R. rattus increased markedly in more degraded sites. This latter finding will have increasingly important implications when considering the rapid degradation of forests in the region, and the resulting expansion of suitable habitat for this competitive species.

Movement Behavior of Native and Invasive Small Mammals Shows Logging May Facilitate Invasion in a Tropical Rain Forest

“…We have confirmed earlier survey work that demonstrated R. rattus is more likely to be present in heavily modified than unmodified tropical rain forest (Cusack et al . ) and confirmed our hypothesis that this pattern appears to arise from specific, small‐scale alterations to microhabitat structure that R. rattus actively prefers to move in.…”

“…Both Maxomys species and R. rattus showed significant preference for more disturbed microhabitats, corroborating the results of a previous study using trapping data at the same study site (Cusack et al . ). Here, however, we have demonstrated at a smaller spatial scale that these three species choose to move through more disturbed habitats than less disturbed, alternative habitats in the immediate surrounding environment.…”

“…However, these were not significant predictors of occurrence for either Maxomys species or R. rattus (Cusack et al . ). By contrast, we found that all study species showed a significant preference for fallen wood and an avoidance of leaf litter.…”

“…Using trap‐level habitat data, Cusack et al . () found that the occurrence of L. sabanus could be predicted by the presence of fallen wood and low levels of leaf litter. However, these were not significant predictors of occurrence for either Maxomys species or R. rattus (Cusack et al .…”

“…, , Cusack et al . ) and detected in the oil palm plantation matrix surrounding the forests examined in this study (Cusack ). Although this species has not been systematically surveyed across Borneo, the limited data available suggest it is not yet ubiquitous in natural forest areas (Nakagawa et al .…”