A vampire bat with a proximity sensor
Photo: Sherri Fenton / dpa
Usually, vampire bats are highly social animals.
"They care for each other's fur and share food," says biologist Simon Ripperger from the Natural History Museum in Berlin.
Together with two colleagues from the University of Texas and Ohio State University, he now reports in the specialist journal "Behavioral Ecology" how the behavior of animals changes when they are sick.
According to this, infected animals significantly reduce interactions with conspecifics, which protects others from pathogens.
"We suspect that keeping your distance is a natural reaction, because the sick bats were lethargic and slept more," said Ripperger.
The behavior has already been observed in bats in captivity, said Ripperger.
The scientists have now proven it for the first time in a field experiment in Belize.
To do this, they caught 31 females from a group and administered a substance to half of the animals that simulated a bacterial infection for six to twelve hours.
Changes in the social network recorded every second
The animals were also equipped with novel proximity sensors - a kind of mini-computer, lighter than a 1-cent piece - and released into the wild.
"The sensors record exactly to the second who is close to whom. In addition, it is possible to measure how close the animals are," explains the biologist.
Changes in the social network of an entire colony could be observed every second.
The analysis of the data also showed that the symptoms of the disease profoundly changed social networks.
Sick bats spent less time with group members.
At the same time, the likelihood that a healthy animal will come into contact with a sick one decreased.
Social distancing is a simple but effective mechanism for vampire bats too, according to the Natural History Museum.
Icon: The mirror
chs / dpa