Do you know what a group of bats is called?
If you guessed a “colony,” you’d be correct! If you guessed a “camp” or a “cloud,” you definitely know some obscure bat facts!
Colony, camp, or cloud, let’s talk about bat social dynamics.
Many species of bats live in colonies. These groups range largely in size. Bats like the Mexican Free-tailed bat can live in huge colonies, the biggest being 20 million individuals in Bracken Cave in Texas. Other bats, like the spectral bat, form smaller groups of an adult male and female pair, and their offspring. Some bats live in pairs or trios.
Photo of Bracken Cave emergence by Stephanie Lee Shelton
Many fruit bats, like the ones that live at Lubee, live in groups of thousands of individuals. Their group dynamic is called a fission-fusion social structure. This means they’ll aggregate in large groups, but divide themselves up into smaller groups within the larger one.
For example, many fruit bats will split themselves into male and female groups, which is why they are separated like that here at Lubee. Even among these smaller groups, they’ll split again, with dominant males taking the best territory and females. In certain places, multiple species will congregate together and may group up with their species before dividing further. It can get very complicated in these social groups!
Here at Lubee, our bats live in groups of anywhere from four to eighteen bats. In most cases, our pens are all female or all male, with a few exceptions. Living in these groups is incredibly important for their mental and social well being.
Different species of bats roost together too. In places like the UF bat houses, there are bats from many different native species that live together. The seven Lubee bat houses on Lubee property have a combination of Mexican Free-tailed bats, Tri-colored bats, Southeastern myotis, and other Florida native bats. Different species of vampire bats, who are native to Central and South America, are known to nest in the same caves. In Australia, the four species of flying fox, the Grey headed flying fox, Spectacled flying fox, Little red flying fox, and Black flying fox, have been seen roosting together.
At Lubee, many of our pens have more than one type of bat living in them, some pens with up to four or five different species! Since this is a naturally occurring behavior, it provides our bats with good social interaction and enrichment.
Photo by Animal Keeper Anna Archer
With bats living in such large groups, they are often observed participating in social behaviors. Fruit bats will groom each other to get those hard to reach spots. Vampire bats are known to bring blood back to colony mates that are sick, nursing, or pregnant. In maternity groups, females will allow pups that don’t belong to them to nurse from them, a practice called allo-suckling.
Alongside allo-suckling, female bats have bat midwives! Bat midwifery was first noted by bat expert Thomas Kunz in 1994 with Rodrigues flying foxes, and isn’t extremely common, but has been repeatedly observed. In Australia, rehabilitators have observed female flying foxes helping other females who were struggling to give birth and then grooming the newborn pup once it was successfully birthed.
Bats have a couple different ways they’ll mate, depending on their social dynamic. In some bat species, males will mate with more than one female, to ensure that they have as many offspring as possible. This is called polygyny and is common in the animal kingdom. It is the way our fruit bats at Lubee reproduce: one dominant male with lots of eligible females. Once the breeding season is over, males will return to their bachelor groups and females will form maternity groups.
Maternity groups are made up of pregnant females and females with pups. In many species of bats, these females will separate themselves from males to care for each other and their pups. Groups like this will often roost in bat houses, caves, and trees together. They will bring food back for each other and nurse pups that don’t belong to them. Maternity groups are extremely sensitive and will often return to the same nesting area year after year.
In Florida, it is actually illegal to disturb or remove a group of bats from a man-made structure between April and August. This is the Florida maternity season, when pups are born. Because bats are particularly vulnerable to disturbances, they have laws to protect them and their pups!
Back to breeding, in other bat species, males and females will both mate with multiple partners. This is called promiscuity. This allows both parties to make sure they’re getting the best genetics for their offspring. In these cases, male, females, or both may have certain physical traits that make them more attractive to the other sex.
In a few bat species, like the spectral bat and the yellow-winged bat, they form adult pairs that take care of their young together. This is called monogamy and is considerably rare not just in bats, but in mammals. Monogamy can be long term, for many seasons or a lifetime, or short term, for one set of offspring.
©José G. Martínez-Fonseca
And for all the single people out there, some bat species are solitary. Not all bats live in large groups. Solitary bats spend the majority of their time by themselves, only coming together to mate. The Little golden-mantled flying fox is a solitary fruit bat. Male Little golden-mantled flying foxes can be extremely territorial and aggressive towards other males, so they need their space. Here in Florida, one of our solitary bats is the Northern yellow bat. These bats will roost by themselves in dead palm leaves, where they blend right in, so be extra careful when trimming dead palm fronds.
Photo by Michael Durham of Minden Pictures
In 2024, take a note from bats and find yourself a colony of support!
To all our batty friends out there, stay social!
Sources:
Comments