New insights into the special sensors that give bats their incredible maneuvering ability in the air could lead the way to vastly improved aircraft designs.
Bats are remarkable, not only for the way in which they navigate but also for the speed and agility they display in catching prey. A common insect-eating bat can eat up to one-third of their body weight in flying insects per night. That means that, over the course of a year, a group of a thousand bats will eat four tons of insects.
It wasn’t until 1960 and the development of a special high speed camera that researchers were able to capture images of a bat catching its prey for the first time. At normal camera speeds, when a bat takes its prey, the insect simply seems to vanish when the bat changes direction.
New research from Johns Hopkins University, the University of Maryland and Columbia university shows that bats achieve their precision maneuvers using incredibly sensitive touch sensors. These sensors are sensitive enough to monitor even very slight changes in airflow.
In a paper published in the journal Cell Reports, the researchers demonstrate how the highly sensitive receptors in a bats wings send information about airflow to the brain, allowing the bats to make split-second changes.
“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,” said Cynthia F. Moss, neuroscientist at Johns Hopkins, in a statement.
The researchers studied the big brown bat, which is common throughout North America. They found that the special maneuvering ability is a result of the same evolutionary process that created the bats unique wings.
Bats are the only mammals capable of true flight and their wings share more similarities with the fore-limbs of other mammals than they do with bird wings. In addition to flight, bats can use their wings to climb, carry their young and capture insects.
A special array of sensors, clustered at the base of the tiny hairs that cover the wings, allow the detection of tiny changes in airflow. When the researchers stimulated the hairs with puffs of air, neurons in the bats sensory cortex responded with rapid bursts of activity
To the researchers surprise, they found that the sensors in the wing hairs also connected to lower parts of the spinal chord. This means that the messages about changes in air currents simultaneously flowed through the animals entire upper body.
The study provides new insights into how bats can maneuver so precisely and catch prey in the dark. It could also allow engineers to design air vehicles with vastly improved maneuverability.
