Since early July, SR3’s Dr. Holly Fearnbach and Dr. John Durban from Southall Environmental Associates (SEA) have been able to collect aerial images of the majority of the endangered Southern Resident killer whale population. This ongoing project is using photographs from drones to non-invasively measure growth and body condition to track the nutritional health of the population over time. Quantitative measurements will be generated for all individuals encountered, but obvious shape changes in some individuals have revealed a number of pregnant whales (see images below) from all three pods. This is not unusual, and unfortunately the majority of recent pregnancies have not resulted in successful births. Studies by our colleagues at the University of Washington have shown that these reproductive failures are linked to nutrition and access to their Chinook salmon prey, so we hope folks on the water can give the Southern Residents plenty of space to forage at this important time. With such a small population (Center for Whale Research census current at 73 whales), every successful birth is hugely important for recovery.
L72 pregnancy: The picture panel above shows her shape change between September 2019, when she was several months into pregnancy, and recently in July 2020 when her increased width at mid body clearly indicates she is in the late stages of pregnancy. Pregnancy in killer whales typically lasts 17-18 months. Photos by SR3 and NOAA’s Southwest Fisheries Science Center in 2019 and SR3 and SEA in 2020, collected under NMFS research permit 19091.