Dugongs (Dugong dugon) spend their entire lives at sea, foraging in relatively shallow, often turbid coastal waters. Investigating the fine-scale behaviour and habitat use of this cryptic species has been hampered by the limitation in tracking technology. However, recent advances in the form of multi-sensor tags provide the opportunity to quantify fine-scale diving behaviour.
In October 2019, we tested, for the first time, the feasibility and applicability of new generation multisensory tags on dugongs in the lagoons of New Caledonia. Two mature female dugongs were successfully equipped with mini diary tags, that recorded data from movement sensors as well as recording pressure, and global positioning systems at a frequency of 50 Hz.
Our preliminary analysis revealed individualistic diving behaviour, with both dugongs performing a range of active and inactive dives throughout deployment. The higher proportion of relatively inactive dives for dugong one corresponded to long residency times, comparatively more active dives recorded for dugong two corresponded to short residency times. Trends in temporal variability suggests more inactive dives between 06:00am – 06:00pm, and active dives between 06:00pm – 06:00am. Results demonstrate the opportunity multi-sensor tags provide in expanding our understanding of the behavioural functions and activity budgets associated with dugong diving behaviour.