Orca mothers endure an extended period of pregnancy, followed by up to two years of nursing and continued food sharing with their adult offspring. A recent study in the journal Scientific Reports reveals the physical toll of this motherhood journey on these marine mammals. The research focused on northern resident killer whales, a species listed as threatened under Canada’s Species at Risk Act, residing in the waters from Alaska to northern Washington.
The study, led by biologist Sharon Kay and co-author Amy Rowley from the Raincoast Conservation Foundation, examined the impact of motherhood on orca body fat levels post-pregnancy. Using drones to capture images of the whales, researchers analyzed changes in the white patches above the whales’ eyes to assess body condition. The findings indicated that the number of living offspring significantly affected the mothers’ body fat levels, with some struggling to return to their pre-pregnancy state due to the demands of caring for their young throughout their lives.
This study sheds light on the challenges faced by orca mothers, highlighting the long-term effects of raising offspring and the societal pressures these animals endure. Despite the natural demands, human-induced stressors such as chemical contaminants, noise pollution, and climate change pose additional threats to these creatures. Understanding the implications of these pressures is crucial as they can further impact the body fat levels of orcas, potentially leading to adverse consequences.