why does a peacock fan its feathers
Male peacocks fan their colourful rear feathers and shake them, but somehow keep their plumes' iridescent circles, or eyespots, nearly still, like a fixed stare. It's a trick that is known to work with the ladies, who are known as peahens. Now a team of US and Canadian scientists has captured the secret to their success. "This 'train-rattling' display attracts the peahen's visual attention and always precedes copulation," they wrote in new study in the journal. Charles Darwin first noted this chase-and-dance behaviour a century and a half ago, but researchers have never fully understood how the biomechanics work. So the team, led by Dr Roslyn Dakin from the University of British Columbia, Canada, studied the mating dance, in which the male shakes dozens of train feathers â each up to 1. 5 metres long â and holds them erect for hundreds of hours of display each breeding season, which may last two to three months. They used high-speed video to analyse the train-rattling movements in 14 adult peacocks. They found the feathers vibrated on average around 25 beats per second, generating a pulsating low-frequency sound that is hard for humans to hear, but in the perfect range for peahens. Previous research has also shown peacocks that display eyespots with greater iridescence are more successful at wooing the ladies.
The researchers found that rapid shaking of the peacock's tail feathers created a dynamic iridescence around the eyespot. "It is possible that this motion also influences how peahens perceive the eyespot colours that are important for mate choice," they wrote. Using scanning electron microscopy the researchers found the eyespots stay so still during displays because they are locked together with microhooks much like those on flight feathers. This gives each eyespot greater density than the surrounding loose barbs, keeping it essentially in place as the loose barbs shimmer in the background, the researchers said. The researchers also found that the longer a male's tail feathers, the faster he was able to shake them. This effort would require more muscular strength, and might be a powerful signal of fitness to the females. "We often video-recorded peacocks train-rattling for more than 25 minutes, suggesting that this behaviour may pose a considerable challenge to metabolic stores and short-term muscle power output," the researchers said. The researchers said their study countered Darwin's view the peacock's dance served "merely to make noise". "On the contrary, our results suggest the possibility that sexual selection via female choice has shaped both the biomechanical design of the eyespot feathers and the behaviours that produce visual and audio cues," they wrote.
With its massive tail and iridescent colors, this bird has long fascinated its human observersÁand weÁre still learning its secrets. For example, a recently published in The British Journal of Animal Behaviour says that when a peacock fans its ornamented train for the ladies during mating season, its feathers quiver, emitting a low-frequency sound inaudible to human ears. Depending on whether they want to attract females from far away or up close, they can change the sound by shaking different parts of their feathers. (TheyÁre not the only animals that create infrasonic sounds. Elephants á with their vocal cords, most likely to communicate over. ) Here are a few other interesting facts about these impressive birds. 1. Only the males are actually Ápeacocks. Á The collective term for these birds is Ápeafowl. Á The males are ÁpeacocksÁ and the females are Ápeahens. Á The babies are called Ápeachicks. Á 2. A family of peafowl is called a Á. Á A group of the birds is also sometimes called an Á,Á a Á,Á or even a Á. Á 3. TheyÁre not born with their fancy tail feathers. The male peachicks donÁt start growing their showy trains until about age three.
In fact, itÁs hard to tell the sex of a peachick because theyÁre nearly identical to their mothers. At around six months, the males will begin to change color [ ]. 4. They donÁt have to be killed for their feathers. Luckily, the peacocks shed their train every yeará after mating season, so the feathers can be and sold without the birds coming to any harm. The average lifespan of a peacock in the wild is about. 5. They can fly, despite their massive trains. A peacockÁs tail feathers can reach up to six feet long and make up about 60 percent of its body length. Despite these odd proportions, the bird flies just fine, if not 6. There are all-white peafowl. Thanks to selective breeding, itÁs common for captive peafowl to buck the iridescent trend for all white feathers. This is called, and itÁs due to a genetic mutation that causes loss of pigmentation. These peafowl are often mistaken for being albino, but instead of having red eyes, animals with leucism retain their normal eye color. 7. Peacocks were a delicacy in medieval times. The birds were plucked, roasted and then re-dressedá in their feathers in their original live state on the dinner table. HereÁs the presentation instructions fromá the body, And serue him forthe as he The birds may have looked beautiful, but they reportedly tasted terrible.
ÁIt was tough and coarse, and was criticized by physicians for being difficult to digest and for generating bad humors,Á writes Melitta Weiss Adamson in her book Food in Medieval Times. 8. They can fake it. These birds arenÁt just nice to look at, theyÁre also clever, according to one recent When peacocks mate with peahens, they give out a loud Ácopulatory call. Á Canadian researchers Roslyn Dakin and Robert Montgomerie discovered that the birds can ÁfakeÁ this call to attract more females. As the BBCÁs Ella Davies, ÁBy pretending they are mating when they are not, the birds could convince females they are more sexually activeÁand therefore genetically fitterÁthan their rivals. Á In fact, one-third of the calls heard by researchers were fake, and the birds that made them scored the most hookups. Sneaky, sneaky. 9. Their feathers are covered in tiny crystal-like structures. What makes the peacockÁs feathers so brilliant? Ácrystal-like structuresÁ that reflect different wavelengths of light depending on how theyÁre spaced, resulting in. Hummingbirds and shimmering butterflies have mastered a similar visual effect on their own wings. All images courtesy of iStock.
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