Wonderfully wacky birds

By Casey Frye, CCNN Writer

blue butterfly
Butterflies and moths are capable of hearing a bird that’s hunting them!

There’s plenty of animals in the world with behaviors that just don’t quite make sense to us. Take this cat I used to own, named Cookie. She’d noisily sprint around the house for hours in the middle of the night, for no apparent reason! Or, how about my dog Daisy, who’d always have to turn around in a circle before plopping down and getting comfy on the rug. As for my turtle Franklin? Well, he didn’t do anything too out of the ordinary. Still, though, animals can act so strange!

Earlier this month, behavioral scientists talked about some of their favorite weirdos, and here’s three of the quirky beasts that’ll be sure to tickle the ol’ funny bone. Of course, once you hear why they do what they do, it won’t seem so silly.

The horrific term “roadkill” refers to animals that die after being struck down by a car. Birds in France don’t have to worry about this though, since they are built with speed detectors! Okay, not exactly, but according to Pierre Legagneux, who published a study in Biology Letters involving 21 bird species, they know the speed limit on different roads! Legagneux got in his car and drove towards birds that were meandering about on a street. The higher the speed limit on the road, the sooner the birds would fly away, regardless of how fast or slow he was driving. Maybe the beaked animals can catch a tasty insect as they wait for the cars to pass.

Aussie Raven
Australian Raven.

Snagging those bugs before they get smashed on windshields won’t be easy, though, because another study published in Biology Letters concluded that certain insects can hear birds approaching! Researchers recorded the sound of birds hungrily flying towards a juicy bug, then replayed the audio for moths and butterflies. While the fearsome sounds of a predator played, the scientists observed the insect nerve responses. Bingo! They matched the rhythm of the flapping bird wings! The authors of the study wrote, “[Birds]… may have played a significant role in shaping the evolution of the vast diversity of hearing organs found in insects.”

When our fine, feathered friends aren’t busy running from cars or hunting moths, you can find them sitting on a branch chirping a happy melody for all the world to hear. Wouldn’t it be wonderful to know the lyrics to their tunes? Actually, it’d be rather boring, because most of the time they’re just shouting out their age for other birds! A study published in the Journal of Avian Biology identified this unique behavior among male nightingales. Researchers measured their wingspan, weight, beak size, chirping sounds, and age, then found that the older males sang at faster and higher pitches than the younger boys.

“Indeed, nightingales may use the full spectrum of their song… to [signal] different information… such as age, condition, and morphology, by using different song traits,” the authors wrote. Trust me, the females definitely noticed the difference, if you know what I mean. In fact, the gals used the male bird songs to determine his age, and were more likely to build a nest with him if he was older.

After reading these cool abilities, I kind of wish my turtle Franklin was a more interesting guy.

Featured image courtesy of Michael Woodruff on Flickr. Butterfly image courtesy of Emmanuel Huybrechts on Wikimedia Commons. Raven image courtesy of JJ Harrison on Wikipedia.