Blue Whale

WTF Fun Fact 13552 – Blue Whale’s Heartbeat

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A blue whale’s heartbeat can be detected from an astonishing distance of two miles away!

The Mighty Pulse of the Blue Whale

The blue whale, known as Balaenoptera musculus, reigns as the largest creature on our planet. Its size surpasses even the mightiest dinosaurs. One of its awe-inspiring attributes? Under the right conditions, you can detect a blue whale’s heartbeat from an incredible distance of two miles away.

The Heart: Size and Scale

First, consider the immense size of the blue whale’s heart. It weighs around 400 pounds (181 kilograms) and is about as large as a small car. This massive organ pumps blood through a creature that can be up to 100 feet long and weigh as much as 200 tons. Each beat sends gallons of blood throughout its enormous body, delivering oxygen to muscles and vital organs.

Mechanics of Each Beat

The rate of the blue whale’s heartbeat also intrigues researchers. When a blue whale surfaces, its heart beats eight to ten times per minute. Yet, during a deep dive, this rate can plummet to a mere two beats per minute. This drop in heartbeat allows the whale to conserve oxygen and stay underwater for durations that can reach 90 minutes.

Each heartbeat exerts tremendous force. As the heart contracts, it generates strong pressure waves. Given the power and size behind each beat, these waves can travel for miles.

Tools of Detection: Hydrophones

Researchers use hydrophones, underwater microphones, to tap into the ocean’s soundscape. These devices pick up a range of sounds, from the melodies of humpback whales to the conversations of dolphins and the distant rumblings of underwater earthquakes. Amid these myriad sounds, the rhythmic thud of the blue whale’s heartbeat offers valuable information.

Water conditions, including temperature, salinity, and depth, affect how sound travels underwater. However, the unique rhythm of the blue whale’s heartbeat stands out, even in this busy sonic environment.

Heartbeat and Conservation

Studying the blue whale’s heartbeat has implications for conservation. Tracking the heart rate can give insights into the health of the species. Human activities, such as shipping or underwater drilling, can stress whales and alter their heart rates. By listening to the ocean’s pulse, scientists can determine the effects of human-caused noise on these marine giants and adjust conservation strategies accordingly.

Additionally, by understanding the blue whale’s heart, we can explore the limits of size in the animal kingdom. This knowledge might explain the maximum potential size of living organisms and provide insights into the evolution of marine giants.

—WTF fun facts

Source: “5 things you never knew about a whale’s heart” — Cold Spring Harbor Whaling Museum

WTF Fun Fact 12901 – Blue Whale Calorie Intake

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It’s no surprise that a blue whale’s calorie intake is massive – after all, they’re the largest creatures on Earth (and the largest animal to ever live). But half a MILLION calories is a lot to take in – especially in just one mouthful of food!

Blue whale feeding

The majority of a blue whale’s diet consists of tiny shrimp-like creatures called krill (interestingly, one of the smallest ocean creatures). According to Smithsonian Magazine (cited below): “A foraging whale lunges into a swarm of these shrimp-like animals, accelerating to high speed with its mouth open at a right angle. Pushed back by the rush of water, its mouth expands and its tongue (itself the size of an elephant) inverts to create more room. The whale engulfs up to 110 tonnes of water and any krill within is filtered out and swallowed.”

Jeremy Goldbogenstudies blue whales at the University of British Columbia. He tagged 265 of the massive creatures to log the amount of energy they expended while lunging to eat. His devices recorded information for 650 feeding lunges.

“The data-loggers recorded the whales’ position, their acceleration, and the noise and pressure of the surrounding water. The noise was important – by measuring the sound of water rushing past the animal, Goldbergen could work out how fast it was travelling.”

Blue whales can move up to 8 mph in less than a minute and 770 to 1900 calories just to work up the momentum to take that big gulp of ocean water. An average feeding dive takes about 10 minutes, and the whales take around 3 to 4 gulps in that time. But they consume from 6 to 240 times the amount of calories they expend.

Blue whale calorie counting

If a blue whale expends so much energy simply diving for food, it makes sense that they would have to take in an enormous number of calories to make it worth the trouble. But it’s hard to believe just how many calories they can take in.

Smithsonian Magazine states: “If a big whale attacks a particularly dense swarm, it can swallow up to 500 kilograms of krill, eating 457,000 calories in a single monster mouthful and getting back almost 200 times the amount it burned in the attempt. A smaller whale lunging at a sparse collection of krill would only get around 8,000 calories, but that’s still 8 times more than what it burned. Even when Goldbogen accounted for the energy needed to dive in search of prey, the whales still regained 3 to 90 times as much energy as they spent.”

This makes it easier to think of all of the rest of our meals as relatively low-calorie, by comparison. –WTF fun facts

Source: “Blue whales can eat half a million calories in a single mouthful” — National Geographic