4. DISCUSSION
Despite extensive research on habitat selection, limited knowledge exists regarding habitat selection status for individual species under multivariate conditions. In this study, we investigated the habitat selection patterns of D. splendidum across different sex and age groups. Results indicated that adult males preferred higher tree positions and areas with lower light intensity and moderate vegetation density. Adults favored higher tree positions and more distant from water sources. Juvenile males showed a preference for higher tree positions, lower rock formations, and shrub and forest habitats while avoiding herbaceous areas. Juvenile females preferred higher rock habitats and or scrubby herbaceous areas.
The observed differences in habitat selection among individuals of different sexes can may be attributed to variations in physiological structure, living habits, and behavior (Conde et al., 2010; Eifler et al., 2007). Adult males generally exhibited a preference for elevated habitats within moderately vegetated environments, similar to the preference for higher tree perches observed in territorial lizards such as Anolis sagrei (Delaney et al., 2016). Male lizards tend to occupy higher tree positions to enhance visibility for guarding territory, engaging in interspecific communication, displaying behavior, and foraging (Song et al., 2017). However, given the greater threats inherent in occupying higher positions, males also prefer habitats with denser vegetation to reduce their risk exposure (Browne et al., 2014; Robert et al., 2006). Females, especially pregnant females, tend to prefer areas with higher safety indices due to their significant investment in reproduction (Eifler et al., 2012; Jerosch et al., 2018). Our results indicated that females preferred lower tree positions or higher rocks, which provide better opportunities to escape from predators. and reduce risks associated with slower mobility, similar to the preference for lower perches and higher foraging observed in female arboreal lizards such as Anolis polylepis (Andrews, 1971). Lizards are ectotherms and their physiology is influenced by external conditions, especially light and temperature (Tan et al., 2019). Notably, we found that adult females preferred higher light intensity, likely to elevate their body temperature, enhance physiological and biochemical responses, and promote gonadal development, thereby influencing habitat selection decisions (Harvey et al., 2010; Melville et al., 2001). Adult females also preferred higher vegetation densities, further facilitating body temperature regulation (Melville et al., 2001).
The differences in habitat selection among individuals of varying ages may also be related to their developmental and physiological diversity (Ficetola et al., 2013). Our findings indicated that adult lizards typically preferred habitats with taller vegetation, which offer more abundant food sources, better concealment, and an extensive canopy that assists in thermoregulation. Vegetation characteristics in microhabitats have been shown to facilitate thermoregulation in animals (Bradley et al., 2022). Similarly, previous studies have revealed that preference differences between adults and juveniles may help reduce ecological niche competition and cannibalism, especially under high population densities (Keren-Rotem et al., 2006). Our results indicated that juvenile males, facing higher predation risks, tended to select larger rocky shelters, shrubs, and ground-level sites in forested areas. This behavior helps reduce daytime visual predator tracking, increase the availability of retreat sites, and lower predation risk (Niewiarowski et al., 1997). Similarly, Keren-Rotem et al. (2006) found that the juvenile common chameleons (Chamaeleo chamaeleon ) prefer low grasslands for concealment, while adults favor shrubs and trees. Our results also demonstrated that adults preferred general or compacted substrate conditions, similar to the habitat selection observed in rock lizards (Iberolacerta bonnali ) (Arribas et al., 2009). This preference aligns with the idea that both species select habitats that minimize negative impacts, thereby facilitating escape or enhancing predation rates (Song et al., 2017; Nemes et al., 2006; Mackey et al., 2010).
Our results revealed significant differences in habitat selection among lizards based on sex and age classes, contributing to existing knowledge on reptile habitat selection and enhancing our understanding of the distribution and specific characteristics of these lizards. Additionally, our findings offer theoretical support and scientific guidance for the conservation of lizards and other species in the dry and hot river valleys of the Hengduan Mountain region. However, the low occurrence rate of lizards during winter and early spring in the study area limited data collection. Consequently, only habitat selection data from the breeding period were analyzed, as year-round data collection was not feasible. It is important to note that habitat selection may vary across seasons, and factors such as temporal migration and interspecific interactions could influence specific habitat preferences of individuals. Therefore, future research will continue to monitor habitat changes influenced by various factors at different scales to address and resolve these uncertainties.