Science may have uncovered the bat’s well kept flying secret. Long having dazzled scientist and animal lovers alike, bats can fly better than any bird, insect or man-built machine, effortlessly switching directions midair, dive bombing, fluttering their wings or simply hovering.
A new study published in the journal Call Reports earlier this week, on April 30th, shows that bat wings are equipped with unique sensory cells hidden at the base of tiny hairs, which help guide their remarkable, complex, agile flights.
The sensors are capable of detecting even the smallest changes in the air passing over the wings, they then send nerve signals to the bat’s brain, which allows it to make precise, split-second decisions about flight path, wing shape, speed and attitude.
Cynthia Moss, study researcher and neuroscientist at Johns Hopkins University, told Live Science “the wing of the bat is really a very specialized structure”. It turns out bats do not only use their wings for flights, but also to catch food (insects), climb various surfaces and cuddle their young.
The study is the first to ever examine the sensors on bat wings. “Until now no one had investigated the sensors on the bat’s wing, which allow it to serve as more than a propeller, a flipper, an airplane wing or any simple airfoil. These findings can inform more broadly how organisms use touch to guide movement” Moss said. She and her team started their work about 2 years ago, focusing on the absence of fine hairs and how it affects flight.
After using a depilatory cream to temporarily render the wings of big brown bats hairless, the scientists went on to measure the bats’ flight behaviors. The results were that without tiny hairs on their wings, bats do not slow down as quickly when they approach objects and their midair turns and maneuvers are less tight.
Moss explained that the hairs “serve as a lever, and when they move, that activates the receptor”.
They then noticed that the bats’ brain cells responded in the primary somatosensory cortex when the hairs were stimulated with air puffs or light touch. They teamed up with Columbia University biologist Ellen Lumpkin, who specializes in touch receptors, and were able to discover the Merkel cells dedicated to fine touch and the lanceolate endings.
The researchers tracked the bats’ brains and found that their neurons reacted with a burst of activity followed by a burst of inactivity, even if the stimulation was long lasting. It suggests the sensory cells are designer for speed and Moss informs that the message they send bats is along the line “OK, here’s the information. Now do something”.
Dr Sterbing-D’Angelo of the University of Maryland said that “While sensory cells located between the ‘fingers’ could respond to skin stretch and changes in wind direction, another set of receptors associated with hairs could be specialized for detecting turbulent airflow during flight”.
To underline the importance of the study, Dr Moss stated that a better understanding of the bat’s flying ability could lead to better plane designs: “This research also lays the groundwork for understanding what sensory information bats use to perform such remarkable feats when flying through the air and catching insects. Humans cannot currently build aircrafts that match the agility of bats, so a better grasp of these processes could inspire new aircraft design and new sensors for monitoring airflow”.
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