Researchers attempting to document the sounds made by giraffes recorded almost 1,000 hours of audio at three different European zoos, even leaving their recording equipment in the enclosures at night.
Advertisement
And there, near the edge of human hearing, the researchers picked up the unusual low sounds giraffes make at night -- the mysterious hum.
The scientists aren't sure why the animals are humming, just that they are and that it only happens at night.
Even zookeepers, they note, have never heard the animals hum.
Giraffes have not been known for their wide range of vocalizations. Describing the animals as "taciturn," the researchers wrote in the journal BMC Research Notes that most sounds identified so far have been described as a "bleat," "brrr," "burst," "cough," "growl," "grunt," "low," "moan," "moo," "sneeze," "snore" or "snort."
Advertisement
The hum is something new, and it may be a form of late-night communication as each zoo had at least one animal separated from the herd at night.
At one location, the creatures were placed in separate stalls. In another, a pregnant female was separated from the herd while the third zoo kept a bull from its group at night.
"These patterns might provide suggestive hints that in giraffe communication the 'hum' might function as a contact call, for example, to re-establish contact with herd mates," the researchers wrote. "Nonetheless, the rich harmonic structure and the frequency modulation indicate that this type of vocalization has the potential to convey relevant information to receivers."
But there is another possibility.
"It could be passively produced -- like snoring -- or produced during a dream-like state,” Meredith Bashaw at the Franklin & Marshall College in Lancaster, Pennsylvania, who was not part of the study, told New Scientist. "Like humans talking or dogs barking in their sleep."
Also on HuffPost:
World's Most Extreme Animals
Advertisement
Support HuffPost
Our 2024 Coverage Needs You
Your Loyalty Means The World To Us
At HuffPost, we believe that everyone needs high-quality journalism, but we understand that not everyone can afford to pay for expensive news subscriptions. That is why we are committed to providing deeply reported, carefully fact-checked news that is freely accessible to everyone.
Whether you come to HuffPost for updates on the 2024 presidential race, hard-hitting investigations into critical issues facing our country today, or trending stories that make you laugh, we appreciate you. The truth is, news costs money to produce, and we are proud that we have never put our stories behind an expensive paywall.
Would you join us to help keep our stories free for all? Your contribution of as little as $2 will go a long way.
As Americans head to the polls in 2024, the very future of our country is at stake. At HuffPost, we believe that a free press is critical to creating well-informed voters. That's why our journalism is free for everyone, even though other newsrooms retreat behind expensive paywalls.
Our journalists will continue to cover the twists and turns during this historic presidential election. With your help, we'll bring you hard-hitting investigations, well-researched analysis and timely takes you can't find elsewhere. Reporting in this current political climate is a responsibility we do not take lightly, and we thank you for your support.
Contribute as little as $2 to keep our news free for all.
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. Would you consider becoming a regular HuffPost contributor?
Dear HuffPost Reader
Thank you for your past contribution to HuffPost. We are sincerely grateful for readers like you who help us ensure that we can keep our journalism free for everyone.
The stakes are high this year, and our 2024 coverage could use continued support. If circumstances have changed since you last contributed, we hope you’ll consider contributing to HuffPost once more.