Australian sea lions (Neophoca cinerea) are an endangered marine mammal with small, declining populations, making effective monitoring of individual health critical for conservation. Body condition is a key determinant of survival and reproductive success, yet traditional approaches often require animal capture, limiting scalability and increasing disturbance.
This study aims to evaluate the use of non-invasive drone imagery to estimate body condition using simple morphometric measurements. Oblique aerial images have been collected from known individuals at Seal Bay on Kangaroo Island, South Australia. Body length and width are being extracted to develop a body condition index (BCI) independent of age and volumetric modelling.
To validate this approach, simple morphometric indices are being compared with residuals from growth models of body volume relative to age, representing relative body condition. Preliminary results suggest strong agreement between width-based indices and model-derived condition, indicating that body condition may be reliably inferred from length and width alone.
This work demonstrates the potential for drone-derived morphometrics to provide a scalable, repeatable, and non-invasive tool for assessing body condition, with applications for long-term monitoring and conservation management of this endangered species.