To look in the mirror and see oneself reflected is a phenomenon we take for grated, but show one to a caveman and- whether they recognized their own image or not- they would not dismiss it arbitrarily. Every animal sends out messages about itself and its surroundings, and if these are played back to it they often respond as if hearing another animal give the same message. If you were saying “there’s a cat nearby” and your neighbor said the same thing, you would not necessarily be concerned. But sometimes, animals do not respond to their own signals as expected.
Bark beetles play a crucial role in forest ecology because they reproduce in the inner bark of living and dead trees. This helps decay debris and keep the forest healthy, but they can become a pest if they kill too many live trees where live trees are needed. Researchers have recently found that bark beetles make short squeaky sounds as they burrow through the bark, and played a recording of their sounds to bark beetles to see how or if it would influence their behavior.
It certainly did.
The beetles veered off their straight lines into tight circles and spun around, they attacked and ate each other (cannibalism is not normal behavior) and even tried to eat through the plexiglass of their container when this experiment was performed in the lab! Research is being done into how these signals can be used to redirect the beetles out of live trees. For those who are curious, the question of if this is ethical treatment of a species has been brought up, but only briefly.
I have never heard of being driven so insane by one’s own signals before. But it does make me wonder, if a creature of limited intelligence heard its own “voice” being directed at it, would we really expect them to react differently? The oddity is that they have any sense of “my own signal” at all. That they recognize themselves, so to speak, in the mirror.
-Alice Trei
Wow, that is very strange..you said cannibalism is not normal, do you know if they have found other rare circumstances in which this occurs? I can't believe they acted so strangely by hearing their own voice. I wonder if other living organisms display strange behavior when their own sound is played back.
ReplyDelete-Katie Cyr
That’s really odd! I can’t imagine why they would react so strongly. As you mentioned, they may have little intelligence. Maybe they instead thought it was another group of beetles nearby and as a result, they resorted to defensive behaviors?
ReplyDeletePosted by Katie Kalutkiewicz
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ReplyDeleteI wonder if this experiment has been repeated on any other species of insects. I wonder why they chose to study the bark beetle. Maybe other species don't make noises as they burrow through trees.
ReplyDelete- Amanda Grafstein
That seems like a pretty intense reaction. My concern with this method would be that It did not prevent the burrowing but rather just redirected it to the next available thing which in this case would be the plexiglass. Untill the figure out a way to make them redirect themselves towards dead trees I really don't see a purpose for this. Did they mention why they turned to cannibalism?
ReplyDeletePatrick Salome
I'm a little confused by this experiment, are the squeaking sounds just the sounds mechanically produced while burrowing through the bark, or are they produced by the caterpillar as a signal? Because if they are just the sounds made while chewing through bark, you wouldn't really expect them to have individually identifiable characteristics right? Maybe the reaction the caterpillars have is the result of something else in the experiment, like not being able to escape the constant noise. Either way, I think it would be a really cool and environmentally safe alternative to pesticides if used to control beetle populations in live trees.
ReplyDelete-Jane de Verges
This was discovered in Bark beetles because of a recent epidemic- the amount of live trees they've taken down recently is much higher than it has been even under extreme conditions in the past. Researchers thought that if the species had become so energetic, they might be making interesting noises.
ReplyDeleteThe noises they make are described as "birdlike chirps, squeaks and scratching." While the scratching is mechanical, it seems the chirps and squeaks are not quite so. I don't think they have a fully developed vocal system, but if there are slight differences in individual physiology within the species, then even mechanical signals could contain identifying information!
-Alice Trei
Thats really interesting, do scientists know what the noises the beetles make signals when the beetles are in a natural setting?
ReplyDeleteCharles Carville
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ReplyDeleteInteresting post! If research is being done to playback their own signaling sounds into driving them out of live tree barks, I wonder how it would effect their population negatively!! You mentioned the question of "ethical treatment", so going back to it, shouldn't the research be unethical if these beetles are responding to their own playbacks as cannibalism?
ReplyDeleteLoba Alam