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Just because animals are unable to talk like you and me doesn’t mean that they are unable to communicate with each other. In the case of giggling hyenas, growling dogs, squeaking catfish, singing woolly bats and beeping honeybees, certain sounds and actions are rich in meaning and symbolic of complex animal communication systems.
Giggling Hyenas: Laughing With You, Not At You
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If you ever see a hyena laughing at you, don’t take personal offense. According to recent research in the journal BMC Ecology, the giggling that comes from spotted hyenas is used to convey information about age, dominance and identity. More specifically, the pitch of hyena giggles details age while note variations describe dominance and subordination. Such hyena giggles are typically heard during contests for food and are a good way for these animals to establish some sort of order rather than a free-for-all, feed-all.
More to a Dog Growl Than What Meets the Ear
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According to a recent study, specific meanings are embedded in different types of dog growls, which are used by canines to convey important cues to each other. After recording three types of dog growls (one from a friendly dog looking to play tug-of-war, another from a concerned dog threatened by a stranger, and yet another from a protective dog guarding food) and then playing these sounds from a hidden speaker, researchers were surprised by the reactions of a dog approaching a bone. When hearing the friendly and threatened dog growls, the inquisitive dog stopped for a bit to listen to the growls and then continued in the pursuit of the bone. However, when hearing the protective growl, the dog jumped back from the bone, apparently getting the message to leave the food alone and suggesting a hidden meaning behind dog growls. Two things that especially surprised the researchers were how similar the threatened and protective dog growls were in sound but how different the approaching dog’s reaction was to these two types of growls.
The Squeaking Catfish Says: Give Me That Filet-O-Fish
(Images via: Daily Mail, Info Wave Media, Madgeburger Joe, Aces)
If you find yourself fishing this spring and pulling a squeaking catfish out of the water, chances are the fish may feel threatened (and rightfully so with a hook in its lip). According to a recent study in the journal BMC Biology, catfish communicate to each other by rubbing the spines of their pectoral fins into shoulder grooves, thus making a squeaking sound. Typically, the catfish squeaking sounds are used to warn other catfish of potential predatory threats in their areas and to communicate when competing, presumably for food or a mate. What especially surprised the researchers is that both young and old catfish squeak to communicate, with the squeaking sounds growing in intensity and length as the catfish age. Based on this finding, researchers have determined that catfish squeaking is a much more complex communication system than what it’s been credited for in the past.
Clear-Winged Woolly Bat Signals
(Images via: Budak, Ecology Asia, Flickr, Animal Pictures Archive)
A recent study in the Royal Society Biology Letters declared that the highest pitched calls in nature come from the clear-winged woolly bat, which can reach initial frequency ranges of 235-250 kilohertz (approximately 120 times higher than those of human female singers) and move from higher to lower notes at a frequency range of up to 170 kilohertz (compared to less than 2 kilohertz for a human singer). While the audio abilities of the clear-winged woolly bat are certainly impressive, what do they mean? Apparently, these bats emit a series of echoing calls that help relay information about the size and location of prey to other bats. Amazingly, the bats increase the frequency of their calls as they got closer to the prey, with the researchers suggesting that there are different bat calls to distinguish from insects, spiders, leaves, twigs and other potential sources of food.
Honeybee Stop Signs: The Headbutt and Beep Beeps
(Image via: Neurophilosophy)
Honeybees are known for doing a waggle dance (see above image) to communicate with each other about fruitful feeding sites near their hives. However, when trouble is looming at a feeding site, the bees will alter their communication by headbutting and beeping at each other, according to a recent study in the journal Current Biology. In the past researchers thought that bees could only deliver excited messages; however, this viewpoint changed during a study in which the bees reacted to simulated attacks by predatory crab spiders. By apparently butting heads and beeping, the bees were able to warn each other to avoid the dangerous feeding site, with these bee signals essentially acting as a stop sign and demonstrating the first ever inhibitory or negative message from bees.