A Drone Survey of a Feral Population of Emu, <i>Dromaius novaehollandiae</i> (Latham, 1790), on Rēkohu / Wharekauri / Chatham Island, Chatham Islands

Species monitoring and surveying is strongly limited by habitat accessibility. A feral population of emu ( Dromaius novaehollandiae ) established from five birds deliberately released on Rēkohu / Wharekauri / Chatham Island more than 30 years ago has not yet been quantitively assessed with respect to its population number and status. To address this issue, we conducted a short manual UAV (drone) survey on a portion of the area where this population is said to be concentrated. In total 303 min of flight/survey time over 5 days (January 2025), we made 70 observations of emu, including 45 adults and 25 juveniles, with a calculated 13.5 emu observations per drone hour. The most observations in a single day were 28 individual birds; 17 adults and 11 juveniles. The largest flocks of emu were six individuals: three adults with three juveniles, and another flock of an adult with five juveniles. There is a need for a more extensive survey to estimate the total population size and a more detailed investigation into the ecology of this population to ascertain the potential impact emu may have on the farmland and associated indigenous terrestrial ecosystems on Rēkohu. Emu have also been released in several locations in Aotearoa / New Zealand, and we advocate for similar studies there.