Spacing pattern of the Crested Serpent-eagle (spilornis cheela hoya) in Southern Taiwan

We studied the home ranges and core areas of a native population of Crested Serpent-eagles in southern Taiwan by radio-tracking from November 2005 to May 2007. Mean home range areas for eight male and six female individuals were 16.65 km ² and 6.93 km ² based on the estimation by the minimum convex polygon (MCP) method and 4.52 km ² and 1.46 km ² based on the 95% fixed kernel (FK) method, respectively. Mean core areas for males and females were 1.16 km ² and 0.36 km ² based on the estimation by the Area Independent Method (AIM) and 0.64 km ² and 0.20 km ² based on the 50% FK method, respectively. Mean fixed kernel home ranges of males were 3.1 times greater than those of females, and AIM core areas of males were 3.2 times greater than those of females. All of the individuals exhibited core area overlap, especially in the case of male to male core areas. Male to male, male to female and female to female average AIM core area overlap was 37.0%, 14.9% and 1.9%, respectively with these differences all being statistically significant. Therefore, at the level of AIM core area overlap, core areas of females were smaller, and female to female relationships showed considerably more range exclusivity than those of male to female and male to male. In contrast, male core areas were more regularly shared with other male or female individuals. Since radio-tracked females were 18% heavier than radio-tracked males, we discuss how the differences in spacing pattern may be caused by female dominance.