Habitat use of invasive chital deer is associated with soil mineral content

Context Ungulates have been introduced to many environments around the world. Some of these populations have become invasive, resulting in severe economic, social, and environmental impacts. In 1886, chital deer (Axis axis) were introduced to north Queensland, Australia, and the population has since grown and expanded. Aims To understand where chital deer are likely to occur in the future, we examined the relationship between chital deer abundance and environmental variables at two scales, namely, local and regional. Methods The local scale was surveyed using camera traps on a single property, and regional scale data were collected from a landholder survey of properties across the current distribution of chital deer in the region. Key results High predicted soil phosphorus was correlated with high relative abundance of chital deer at both the local and regional scales. In addition, at the local scale, higher predicted soil sodium content and normalised vegetation index (NDVI, ‘greenness’), close proximity to homesteads and highways, and lower canopy cover and height were strongly correlated with increased chital deer abundance. Conclusions There were more chital in areas with high predicted soil phosphorus at both local and regional scales. Implications This study has the following two implications for management: (1) areas with high predicted soil phosphorous content had the highest relative abundance of deer at both scales, and should be the focus of control efforts, and (2) such areas are more vulnerable to future invasion of chital deer and should be monitored closely.