Southern right whales (Eubalaena australis) return to a former wintering calving ground: Fowlers Bay, South Australia In press: Marine Mammal Science
Claire Charlton, Rhianne Ward, Robert D. McCauley, Robert L. Brownell Jr, Sacha Guggenheimer, Chandra P. Salgado Kent, John L. Bannister
Southern right whales (SRW), Eubalaena australis, have reoccupied historically important winter habitat ranges (calving grounds) in recent yrs along the southern Australian coast. Here we present findings of increased abundance of SRW at Fowlers Bay, South Australia, a previous shore based whaling station. This study investigates: SRW inter and intraseasonal trends in relative abundance; changes to the relative proportion of the south western subpopulation represented by SRW at Fowlers Bay; distribution, and occupancy. Sighting and photo identification data were collected during annual aerial (1993-2016) and vessel surveys (2014-2016). The total number of female and calf pairs was three during 1993-2003 and 63 during 2004-2014. Despite high variability in annual relative abundance, the rate of mean increase (29.0% yr-1 95% CI = 0, 54.2) exceeded the maximum biological rate for the species (6%-7% yr). Peak relative abundance was recorded in July/August. SRW at Fowlers Bay represent an increasing proportion of the south western subpopulation (range=0.9%-7.4%). Mean occupancy was 23 d (range=1-75) for female and calf pairs and 2 d (range=1-15) for unaccompanied adults. Reduced sightings in 2015 and 2016 demonstrate plasticity in SRW abundance at Fowlers Bay. Research into the movement and connectivity of SRW is needed to understand drivers of habitat dispersal in Australia.