Researchers have created a tracker that will record the activities of tiny or small animals that fly around and crowd together in caves and hollow trees.
The wireless network developed by researchers contains functions similar to what we find in our smartphones - such as motion detection and Bluetooth-style connectivity - at a fraction of the weight and energy consumption.
This observation is made possible by attaching little backpacks to the animals with glue. These high-tech backpacks, which can communicate with each other and ground-based receivers, provided data for the popular study published in 2019 showing that vampire bats developed social bonds in captivity that they also maintained in the wild.
Keeping the system automated and lightweight was critical to the success of the network to track adult vampire bats, which weigh between 1 and 1.5 ounces and grow to 3 and half inches in length.
Using devices that can track larger animals, such as those incorporated into harnesses or necklaces, wouldn’t work for bats or other small species.
The sensors often get scratched off in the bats’ roost in about two weeks. The researchers retrieve them if they can to recycle the backpacks and recharge and reuse the batteries.
Though the study describes the complexity of constructing the network and testing its effectiveness on bats, the system would work for other animals, such as birds, rodents, reptiles and amphibians.
The network consists of the tiny computers - accelerometers producing data when the bats are moving and proximity sensors to show when they are close to each other - all encased in each 3D-printed plastic backpack that weighs less than a penny.
A series of base stations on the ground pick up signals and record data on bats’ social activities and flight trajectories. The components are asleep most of the time, waking up when they receive a signal from another bat and then broadcasting every two seconds.
Despite the low power, the network produced robust results in various studies of different species of bats. A two-week test in which 50 vampire bats were tagged produced data on almost 400,000 individual meetings.