Killer whales, also known as orcas, have long been a subject of fascination for researchers and marine enthusiasts alike. A recent study conducted by the University of British Columbia has shed light on an interesting aspect of these majestic creatures’ behavior – their breathing patterns. The study, published in PLOS ONE, confirms a long-held assumption that orcas take just one breath between dives.
The research team utilized drone footage and biological data from tags suction-cupped to 11 northern and southern resident killer whales off the coast of British Columbia to gather valuable information on the animals’ habits. The study revealed that killer whales spend most of their time making shallow dives, with the majority of dives lasting less than one minute. The longest recorded dive was 8.5 minutes, undertaken by an adult male.
Dr. Andrew Trites, a professor at the UBC Institute for the Oceans and Fisheries (IOF) and co-author of the study, likened killer whales to sprinters without the marathon endurance of other whale species like blue and humpback whales, which are known for their deep and prolonged dives.
Confirming that orcas take only one breath between dives allowed the researchers to calculate the amount of oxygen consumed by adult and juvenile whales per minute. This data is crucial in estimating orca energy expenditure and determining the daily food requirements of these animals. Tess McRae, a master’s student at IOF and the study’s first author, emphasized the importance of understanding orcas’ dietary needs, especially for the endangered southern resident population, in their conservation efforts.
Comparing the breathing rates of killer whales to humans, the study found that orcas take 1.2 to 1.3 breaths per minute while resting and 1.5 to 1.8 breaths per minute while traveling or hunting. In contrast, humans typically take around 15 breaths per minute at rest and 40 to 60 breaths per minute during exercise. Dr. Beth Volpov, an IOF postdoctoral fellow and co-author of the study, described the orcas’ breathing pattern as akin to holding your breath while running errands and only breathing again upon returning home.
The study’s findings provide valuable insights into the unique physiology and behavior of killer whales, highlighting the intricate balance between their diving habits, oxygen consumption, and dietary requirements. By unraveling these aspects of orca life, researchers aim to better understand and support the conservation of these iconic marine mammals.
