My Mom was fascinated by the stories Terry and I told her about whales. She loved to hear about their curiousity and intellegence; how the grey whales enjoyed teasing the tourists in Baja and how the humpbacks here seemed be attracted to the sounds of the didjeridoo. Mom, Chayashi, died in May of this year from dementia. But even in advanced stages of dementia there were lucid moments during which hearing about whales would put a smile on her face. With all of the Mom care this year and the ongoing tasks that need to be done after a loved one dies we didn’t get out on the water until August.

We made the most of our abbreviated time out in SV Blue Parrot. Our complicated methodology was to sail or motor to the general area where we’d seen humpbacks feeding or traveling and hang around waiting for whales. Whenever we shut off the engine I would drop my hydrophone (underwater microphone) over the side of Blue Parrot to listen to the sounds underwater through headphones. Sound travels 5 times faster in water than in air so I could hear the bugle-like inbreath of distant humpbacks through my hydrophone before the sound traveled to me above the water. Very cool.

This video shows what happened when 2 curious Humpbacks whales decided to visit us twice in the same afternoon. We were drifting with our engine off at least 200 metres away from them while they were feeding. It was their clear choice to visit us.

The Amphibiographer’s Secrets to Enjoying Awesome Whale Encounters: It’s vital to respect these wondrous beings, not to chase, annoy, or disturb them while they are feeding or sleeping at the surface. Slow down in known whale feeding areas and be aware so you don’t run over one. If you see a blow slow down, there may be more around. If they approach you, stop moving, shut off your engine and enjoy the encounter until they leave you.

Whales have an enormous hearing capacity which is very useful over their huge migration range to stay in contact with each other. In their northern or southern feeding grounds they travel through water that is full of plankton and very murky. They depend on sound to communicate and to find their way underwater.

Humans hear sound frequencies from 20Herz to 20,000Herz. But long distance whale communications can be lower than 10Herz and travel thousands of kilometers. When orca, dolphins or porpoises are echolocating they produce a barrage of very loud staccato blips or clicks at frequencies higher than 100,000herz . Some research suggests that baleen whales like humpbacks may echolocate using low frequency sonar but they do not have the very high frequency capability of porpoises or dolphins or even the toothed whales. There doesn’t seem to be definitive research that nails down the range of frequencies humpback whales can hear. Happily we humans can thrill to their intricate songs because Humpbacks sing predominantly in the hearing range of humans.

Here is a fascinating and playful introduction to hearing ranges in familiar animals.

https://www.myihp.co.uk/animal-hearing-ranges/

I would love to know whether the humpbacks that Terry and I were serenading in this video sang back to us underwater. I will need a spectrograph that maps audio frequencies to interface with my hydrophone in order to discover whether they are vocalizing outside our human audible range. Stay tuned to find out!