SR3’s Dr. Fearnbach and colleagues from NOAA’s Southwest Fisheries Science Center, Vancouver Aquarium’s Coastal Ocean Research Institute and Canada’s Department of Fisheries and Ocean and recently published a paper in Endangered Species Research (https://www.int-res.com/articles/esr2019/40/n040p183.pdf) on their aerial photogrammetry study of Northern Resident killer whales (NRKWs). Based on four years of drone imagery off northern Vancouver Island, this study documented growth to smaller adult sizes of NRKWs in recent decades, mirroring the growth trends Fearnbach and colleagues previously reported for endangered Southern Resident killer whales (https://www.int-res.com/articles/esr_oa/n013p173.pdf) and providing further evidence of correlated prey limitation in both populations. This evidence of constrained growth suggests that the effects of nutritional stress are not only lethal at times, but also have long-term consequences for the condition of whales in both populations.
Vertical aerial image of Northern Resident killer whales. Such images are being used to compare their growth and body condition to that of endangered Southern Resident killer whales. Image collected using an unmanned hexacopter at altitude of >100ft above the whales, permitted in Canada under the Species at Risk Act and flight authorizations from Transport Canada.