Ontogenetic differences in the spatial ecology of immature Komodo dragons

The early life history stages of reptiles are extremely important to an individual’s fitness, but in an ecological sense, amongst the most difficult to observe. Here we used radio-tracking techniques to describe differences in movement patterns, habitat use, and home range between hatchling and juvenile Komodo dragons (Varanus komodoensis) on Komodo Island, Indonesia. Movement of hatchlings from their nests was largely linear and suggested a natal dispersal event. Movement patterns of juvenile Komodo dragons exhibited greater spatial overlap than hatchlings indicating greater site fidelity and thus use of a more defined activity area. Rates of daily movement were significantly less for hatchlings compared to juvenile dragons. The activity areas of hatchlings were significantly smaller than juvenile dragons. Both age classes preferred utilizing dry monsoon forest compared to other habitat types. Hatchlings were predominantly arboreal compared to juveniles and the degree of arboreal activity was strongly correlated with an individual’s size. These distinct differences in spatial ecology between immature life history stages suggest that different selection pressures may affect different size classes of Komodo dragons.