A new study has revealed how bats fly to capture their prey. The work undertook involved night time recordings using night vision equipment.
Fit as a bat
Bats are incredibly efficient travellers and each night time the average bat will cover between 600-700 Kms in distance. They cover most of these distances close to the ground and can catch their prey at about at speed of fourty metres per second. Bats target their prey using an advanced hearing and navigation system that enables them to capture insects at this high speed.
Bats send out ultrasonic waves at an incredibly high frequency. The signals are sent at 20-100 kilohertz which is far too highly pitched for humans to observe. The signals that are sent out are bounce back to the bats within their environment as an echo. Through these echoes, the bat maps its environment within its mind so that it understands how it should be directing itself.
Recent bat research was undertaken by Nadav Bar from the Norwegian University of Science and Technology, and he said, “You can compare echolocation to using a flash in a dark room. The flash hits various objects in the room that light up and are reflected back to the eye of the observer. The bat uses sound in the same way to get an overview of the environment, but the potential sources of error are far greater when using sound.”
Daytime and nightime flights
Interestingly when bats fly during the day they use sight to determine where they are going but this is rare. They fly directly to their destination and don’t use the darting flight pattern that is familiar with the night flights. They typically dip, rise and dart using large moves to generate speed and flight.
Bats to get interference from other noise issues within their environments when they fly at night and day and the echo signals also get disturbed by their own movements. Despite this, bats continue to catch their prey within poor weather conditions. This led Navdav Bar to further explore bat behaviour and flight.
Bar established that bats are able to run a noise filter to remove ambient noise using low pass filtering. The sounds that the bat determines are useless are removed from their observations to create a much clearer scenario for them to create their flight mapping. Bats also have an incredibly developed Sensorimotor which delivers amazing precision to its movement.
En route control
It was noted that the bats were more careful with their movement during night time flights compared to day time and are ever ready to change direction to avoid any collision. Bats also have an ability to determine how quickly the flight angle is changing during the flight as they get closer to their prey.
All of the bat studies were undertaken in the USA, Germany and Poland within facilities that included deserted buildings and caves where bats prefer to gather.