Killer Whales Take Single Breath between Dives, Marine Scientists Confirm

To gather information on the animals’ habits, University of British Columbia’s Professor Andrew Trites and his colleagues used drone footage and biological data from tags suction-cupped to 11 northern and southern resident killer whales (Orcinus orca) off the coast of British Columbia in Queen Charlotte Sound, Queen Charlotte Strait, Johnstone Strait, and Juan de Fuca Strait.

“Killer whales are like sprinters who don’t have the marathon endurance of blue and humpback whales to make deep and prolonged dives,” Professor Trites said.

Professor Trites and co-authors found that killer whales off the coast of British Columbia spend most of their time making shallow dives, with the majority of dives less than one minute.

The longest dive recorded was 8.5 minutes, for an adult male.

Confirming the animals take only one breath between dives allowed the researchers to calculate how many liters of oxygen adults and juveniles consume per minute.

This provides another piece of the puzzle in estimating orca energy expenditure, and eventually, how many fish the animals need to eat per day.

“We can then work out if the orcas are getting enough food, including the endangered southern residents, a key factor in their conservation,” said Tess McRae, a student at the University of British Columbia.

Killer whales in the study took 1.2 to 1.3 breaths per minute while resting and 1.5 to 1.8 while traveling or hunting.

Comparatively, humans tend to take about 15 breaths per minute when resting and from 40 to 60 while exercising.

“It’s the equivalent of holding your breath and running to the grocery store, shopping, and coming back before breathing again,” said Dr. Beth Volpov, a postdoctoral researcher at the University of British Columbia.

The findings appear online in the journal PLoS ONE.

_____

T.M. McRae et al. 2024. Killer whale respiration rates. PLoS ONE 19 (5): e0302758; doi: 10.1371/journal.pone.0302758