Corridors, Community and Koalas – connections for protection: koala population density surveys

Koala (Phascolarctos cinereus) populations are declining in Queensland due to threats including habitat loss, fragmentation, and disease. Effective conservation requires current, accurate data on distribution, health, genetics, and habitat use. However, current management actions are seldomly based on on-ground data. The aims of this study were to fill identified knowledge gaps in the distribution, density, health and diet of koala populations within the Gympie region. This study applied a multi-method approach, including detection dogs, thermal drone surveys, and genetic and dietary analysis of scats, to assess koala population metrics across 19 sites in the Gympie region. Koalas were found at low but variable densities (0.01–0.12/ha), where some areas had experienced noticeable declines. Chlamydia was detected in 40% of koalas, with some hotspots in high-density sites. Genetic analysis showed healthy diversity, a balanced sex ratio, and low genetic differentiation, suggesting ongoing landscape connectivity. Diet analysis revealed koalas consumed a minimum of 20 tree species, including E. longirostrata, not previously recognised as a local food tree. The report findings challenge assumptions in current habitat mapping, and highlight the need for evidence-based planning for koala conservation. This study also provides a framework on how to effectively generate baseline population metrics in areas where koala populations are understudied.