I’m sure you’ve seen a photograph of the red-eyed treefrog (Agalychnis callidryas) from Mesomerica. With bright red bug-eyes, a day-glo green upper body, turquoise legs, and orange belly (as well as a weird call that resembles a baby’s rattle), they’re on many of the animal calendars that appear each winter.
A new paper in Current Biology also shows that these frogs also have a unique behavior. It’s all about sex, of course. To warn competitors away, males hold onto their branch and shake their rumps up and down, producing a characteristic vibration that rattles nearby branches. This often leads to a bout of wrestling between males. I could describe the paper further, but it’s better summarized by this nice report from the last Science Friday. Be sure to watch to the end, because the frog’s eggs also respond to vibrations! (Click on the screen to begin; if that doesn’t work go to the Science Friday link.)
[vodpod id=ExternalVideo.943922&w=425&h=350&fv=%26file%3Dhttp%3A%2F%2Fwww.podtrac.com%2Fpts%2Fredirect.mp4%3Fhttp%3A%2F%2Ftraffic.libsyn.com%2Fsciencefriday%2Fretreefrog-052110.mp4%26height%3D285%26width%3D480%26frontcolor%3D0xffffff%26backcolor%3D0xeeeecc%26lightcolor%3D0xFFFFFF%26showdigits%3Dfalse%26autostart%3Dfalse%26showicons%3Dfalse%26usefullscreen%3Dtrue%26wmode%3D]
When I read about this behavior, my first thought was that the vibrations attracted nearby females, but the researchers haven’t studied that yet. Ten to one the vibrations will prove to be an aphrodesiac.
Now why did the scientists study this, and why was it published in Current Biology? Many papers include what I call a Reason for Uniqueness (RFU): a couple of lines in either the abstract or the discussion that say why your results are new, exciting, and, above all, unique. RFUs always begin in a similar way: “This is the first study that shows. . . ” and so on. All of us like to stick out from the crowd, and we hope that, by making the RFU explicit to overworked editors and reviewers, they will glom on to this sentence and accept our papers. There’s nothing more damning a reviewer can say about a paper than “This doesn’t really show anything new.” (I don’t much like RFUs, which often smack of self-promotion, but I confess that I’ve used them myself.)
At any rate, here’s the RFU for this study:
Although our study provides, to our knowledge, the first experimental demonstration of communication via plant-borne vibrations in a vertebrate, other arboreal vertebrates almost certainly use this communication channel.
This is a good RFU, because it points out related work on social communication involving vibration. But the above is just a fancy way of saying why we really spend our lives making model treefrogs and tree-shaking machines:
Our study provides one more proof that nature is fantastic and full of surprises.
___________________
Caldwell, M. S., G. R. Johnston, J. G. McDaniel, and K. M. Warkentin. 2010. Vibrational signalling in the agonistic interactions of red-eyed treefrogs. Current Biology 20, 
doi:10.1016/j.cub.2010.03.069
I don’t see much harm in a bit of self promotion, as long as it is only a couple of sentences. If this is a typical example, then it appears to be a good way to communicate the awe of science to the average person. The music was tacky though 🙂
For my own part, there’s no real need for an RFU in a paper about the Red-eyed Treefrog. This is such an iconic critter that I’ll immediately read any paper that even mentions its name in the title.
That video is very nicely-done!
Interesting about the dual use (potential dual use). Is that usually the case? Do threat displays tend to be also aphrodesiac? Well duh, I guess – why waste calories and time switching from all puffed up and scary to smoothed down and sexy; just do both at once. Oh baby I love it when you inflate your throat pouch, come on over here.
Elephants do social communication via vibration. They vibrate something inside their heads. Some of it is audible to humans. I used to walk into the barn in the mornings to be greeted by a chorus of rumbles.
So it’s really the booty call it looks like?