Spatial Ecology of the Introduced Chinese Water Dragon Physignathus cocincinus in Hong Kong

Abstract: Basic ecological understanding is important for effective management of introduced species. If the species is rare or threatened in its native ranges, ecological knowledge gained from its introduced ranges may offer useful information for conservation. We radio-tracked 12 adult Physignathus cocincinus in Hong Kong, where it is introduced, to investigate their home range, movements, and habitat use. The home range of all P. cocincinus covered the stream, but 66% of relocations occur >5 m away from the stream. Movements did not differ between sexes and seasons. Females stayed at a longer distance from the stream than males. Lizards preferred woodland and concrete structures over orchards. For microhabitats, they preferred wider streams, greater height, and denser canopy cover. This infers the high association of this species with streams and riparian forests, which may be crucial for the establishment of introduced populations. To effectively manage the introduced populations through eradication efforts, areas away from streams (5–100 m) needs to be covered.