White Spouts in the Chilly Air

If you are a seasoned observer (read: hundreds of hours of observation at a minimum) and weather conditions allow, certain species of whales can be recognized by their spout alone. However, the breath of many species is not usually visible… except under certain conditions.

This is how Whales Online journalist Laure Marandet was able to spot belugas in the Saguenay… by their breaths! As she walks her dogs on the beach in L’Anse-de-Roche on November 1, small plumes flush with the water catch her eye. Then, off Anse-à-Pierrot, she notices that around twenty belugas are swimming together.

Why are their breaths visible today, whereas as a rule, they’re not? Whales have a body temperature similar to our own, i.e. around 37°C. The air inside their lungs is therefore also this temperature. Thus, when six belugas exhale off Saint-Irénée on November 3, the hot air from their lungs condenses upon contact with the colder outside air in this very chilly early November. She watches their ballet for a half an hour.

So why are the spouts of rorquals visible year-round then? In addition to the difference in temperature, since the exhaled air is compressed, the difference in pressure between their lungs and the ambient air causes their breath to condense or vapourize. In this mass of expelled air are also water and oil droplets from the upper respiratory tracts or top of the blowhole, which are more numerous in larger whales.

Thus, the breath of a visiting blue whale in Gaspé Bay is enough to make a couple peer up from their lunch in Cap-aux-Os on November 1. “While we debated whether it was a blue whale or a fin whale, the animal approached and we were able to make a positive ID: it was a blue.” The couple also observe both harbour and grey seals.