Title
Habitat suitability assessment for the endangered Nilgiri Laughingthrush: A multiple logistic regression approach
Author(s)
Zarri A.A., Rahmani A.R., Singh A., Kushwaha S.P.S.
Published
2008
Publisher
Current Science
Abstract
Application of remote sensing and Geographic Information System (GIS) tools has assumed an increasingly important role in conservation biology and wildlife management by providing means for modelling potential distributions of species and their habitats, unlike the conventional ground surveys. We present here a predictive model of habitat suitability for the Nilgiri Laughingthrush, Garrulax cachinnans based on a synergistic use of field surveys and digitally processed satellite imagery combined with features mapped using GIS data layers. Collateral data were created in a GIS framework based on ground surveys comprising layers such as land-use, measures of proximity to likely features of disturbance and a digital terrain model. Multiple binomial logistic regression approach was used for modelling, and the model performance was assessed by the area under the receiver operating characteristics (ROC) curve. About 320 km 2, 25.12% of the area of the Nilgiris considered for modelling was predicted to be suitable for the Nilgiri Laughingthrush. The area under the ROC curve was found to be 0.984 ± 0.003 (R2: 0.93 at P < 0.0001), implying a highly effective model. The assessed suitable habitat was highly fragmented and comprised of 1352 patches (natural as well as man-made) distributed all over the study area. The smallest suitable patch identified by the model was 400 m2 and the largest patch 17.65 km2. Also, ca. 92% of all patches were smaller than 0.5 km2. We presume that some suitable habitat patches may be unoccupied due to strong fidelity of the species to shola (montane wet temperate forest) patches, low colonization rates, or large interfragment distances. Also, larger fragments might serve as source or 'exporters' of surplus individuals to maintain sink populations throughout the rest of the range. We discuss the implication of habitat fragmentation and narrow geographical range and anthropogenic pressure for the conservation of the Nilgiri Laughingthrush.
Keywords
Garrulax cachinnans
Access Full Text
A full-text copy of this article may be available. Please email the WCS Library to request.
![]()
Back
PUB12004