Landscape characteristics derived from satellite-tracking data of wintering habitats used by oriental honey buzzards in Borneo

Abstract

Knowledge of the spatial distribution of the wintering habitats of migratory raptors is a prerequisite to understanding their wintering ecology and managing their habitats. Oriental honey buzzards (OHBs, Pernis ptilorhynchus) are migratory raptors with wintering grounds in Indonesia. OHBs’ wintering habitats can be divided into core and edge habitats with unique landscape characteristics, which influence wintering-site selection. Twenty-three satellite-tracked OHBs (2006–2010) used Borneo as their wintering grounds. The primary aim of this study was to analyze OHBs’ wintering habitat distributions (core and edge habitats) in Borneo and their landscape characteristics in the province of South Kalimantan. Fixed-kernel density estimation was used to estimate the edge and core habitats of 23 OHBs in Borneo. We used a 95 % fixed kernel (FK_95 %) and a 50 % fixed kernel (FK_50 %) to estimate the spatial distribution of edge and core habitats, respectively. Factor analysis was used to analyze landscape characteristics of core and edge habitats. Results showed that edge and core habitats covered about 153,463.4 km2 (20.7 %) and 27,528.3 km2 (3.7 %) of the Borneo area, respectively. Habitat selection by OHBs at wintering sites in both core and edge habitats was highly influenced by the availability of thermal winds and food. However, the more frequent presence of OHBs in core habitats indicates that habitat selection is basically influenced by increased thermal winds associated with particular landform characteristics. Identification of these landscape characteristics provides useful baseline information for ecological-based development, particularly for landscape management and biodiversity conservation.