Even vampire bats strike a social distance when they get sick

The COVID-19 pandemic has taught millions of people around the world at least one valuable lesson. The most important thing you can do to stop the spread of infectious diseases is to keep a social distance. As long as the infected host has limited contact with a healthy host, the pathogen will not spread much. In some cases, the epidemic can be completely eradicated if the pathogen runs out of hosts.

Surprisingly, social distance as a reaction to illness is not just human behavior. Many social animals change their behavior, such as grooming them with aggressive efforts to stop the spread of diseases that can kill them.

For example, the Caribbean spiny lobster (Panulirus argus) Normally living in groups, healthy lobsters avoid members of their species if infected with a deadly virus. Other animals As diverse as monkeys, insects and birds, members of diseases of those species can be detected and avoided.And according to a new study published in the journal today Behavioral ecology, Vampire bat (Vampire bat) Can also be added to the list.

Self-quarantine bat

Previously Gerald Carter, An assistant professor of behavioral ecology at The Ohio State University, found that vampire bats treated with lipopolysaccharide (LPS), a substance that challenges immunity, become lethargic. These bats have less movement and less social interaction such as grooming.

“But studying bats in captivity usually means putting them in an unnatural situation.” Simon Ripper GarA postdoctoral fellow at Ohio State University and a postdoctoral fellow at the Smithsonian Tropical Research Institute in Panama told me.

Based on what they learned from captive research, Lippelger and colleagues visited Lamanai, Belize, to tag and track vampire bats in their habitat. They captured 31 adult females from roosts in hollow trees and injected LPS material into random batches of half of them. The other half acted as a control group and received saline injections.

“We worked at the ruins of Lamanai, a rainforest surrounded by Maya temples. Experience over the past few years has shown that this particular hollow tree has a colony of vampire bats. So I set up a net before sunset, but the first woman did not appear from the tree until 2 am, so I was standing still next to the net in the dark. It was literally eight hours before it was eaten by a bat and finally seemed to work. After three hours, I got the sample I needed. It’s always a very exciting and rewarding moment. ” Ripperger told ZME Science.

Each bat was fitted with a small proximity sensor weighing less than a cent and returned to a hollow tree. This allowed researchers to track the behavioral changes in association made by 16 “sick” bats and 15 controls over time.

“This new technology automatically detects who is near who and sends the data to the base station, which allows us to monitor bats 24 hours a day, 7 days a week. , A major step forward in researching wildlife social networks, and could only bring research from captivity to the wild. At the time, it was the third time we introduced these new sensors, all as planned. It was always very exciting to see if it worked for me. When I download the first batch of data and make sure everything works and most bats stay in the colony, there is always one goose bump. You get, “says Rippergar.

Studies have shown that sick bats spend less time with others and are generally less social with healthy groupmates.

Forty-nine percent of healthy bats were associated with other control bats, but only 35% were likely to mate with each diseased bat. On average, sick bats spent 25 minutes less socializing with each partner. These differences were reduced after the treatment period and when the bats were sleeping or foraging outside the roots.

These findings suggest that induced disease behavior has dramatically altered the social network of vampire bat colonies. However, Lippelger said these changes observed on social networks are “not the result of” sick “individuals isolating themselves and actively avoiding others so that healthy members do not get sick. It’s likely. “

Instead, lethargy and increased sleep are likely to cause social distance, which seems to reduce movement and reduce opportunities for social encounters.

“Imagine you have the flu, you’re exhausted, and you never get out of bed. As a result, you’ll meet fewer people in your daily life,” says Ripperger.

For many social animals, physical distance seems to have evolutionary advantages as it enhances viability. Some species, such as lobster, detect the presence of infected individuals from their odor. When lobster is infected, Releases chemicals into the urine It acts as a warning signal to healthy group members and quickly isolates sick people.

But perhaps the most sophisticated social distancing protocol is Ali. When infectious diseases such as fungi dominate society, Both sick and healthy insects change their behavior quickly.. For example, sick ants self-isolate, but healthy ants reduce their interaction with their peers when they sense the presence of disease in a colony. In addition, healthy ants are known to close ranks around the most vulnerable members of the colony, such as queens and nurses, and to be isolated from foraging ants that are most likely to get sick.

Vampire bats appear to be less enthusiastic about preventing the disease from spreading throughout the community, as research suggests that their behavior is likely a by-product of lethargy. However, their behavior may differ when they encounter a real pathogen that they may be familiar with.

“The difference is that bats aren’t really sick because there are no real pathogens, COVID is caused by viruses, and the molecule used is a bacterium. But the similarities are now in our daily lives. Social distance, which is a major aspect of the virus, is found not only in humans but also in social animals. Apathy causes a decrease in movement, resulting in a decrease in social encounter rate (this is called “passive”). Even simple mechanisms such as (also called “social distance”) can help reduce contact rates between “sick” and healthy individuals and slow the spread of pathogens. ” Said.

In the future, researchers plan to extend fieldwork and monitor vampire bat social networks using proximity sensors, including cattle, which are the preferred prey for bats.

“One of the great opportunities for our sensors is not only to be able to track social encounters among all members of the entire social group in high resolution. The data is so high resolution that the characteristics of a particular pathogen. Can be used to redefine social networks to match. Some pathogens may require close contact between two individuals, others are 1 meter for two individuals. It can already be transmitted when it comes within the distance of. Some pathogens may require a longer period of time to spread, others may spread within 1 minute. Data can be used to filter close or longer encounters and redefine social networks, and these data can be used to model the spread of specific pathogens in this tracking technique. We hope that progress will help future researchers better understand the spread of pathogens in common wildlife populations, “Ripperger said.