Bats, More Bats, and Baby Bats!

By John Greenwood / Published April 2021

In Florida, spring is now upon us, which is nature’s time for new birth, re-birth, and renewal all across the northern hemisphere. Along with the sprouting plants, newborn chicks, and the latest generation of all natural, horticultural, domesticated, and wildlife species, a new generation of furry little pups will be born. However, these pups do not have four legs, floppy ears, waggly tails, and wet noses—they have wings!

     All of Florida’s bats (we have around 15 different species) are born at this time of year, and because all species are protected by the FWC (Florida Fish and Wildlife Conservation Commission), it is illegal to disturb them from mid-April through mid-August. This is because the newly born animals (pups) are unable to fly in the early stages of their development. Companies such as ours, who exclusively perform safe and humane exclusions of bat colonies from buildings that people also occupy, are bound by law to refrain from disturbing them at this time.

     Bats are mammals, and like all mammals, the mothers breastfeed their babies. If we were allowed to perform an exclusion (which is a process by which we allow the adult animals to leave their roost in order to feed but prevent them from returning), any pups remaining in the roof would die of starvation. This brings us to the question that we are constantly being asked by property managers, condominium associations, and homeowners at this time of year: 
         “Do we have to wait four whole months before we can do anything about our bat problem?”

     The short answer is:
         “Well, not necessarily.”

     Here’s the long answer:
     Bats are very long-lived and extremely territorial animals. They have a life expectancy of up to 35 years, which is an incredibly long time for such a tiny physiology (each weighs less than half an ounce). Nature allows them such longevity because they are very good at managing their own population. Readers might be relieved to know that—unlike, say, female mice, who can each give birth to around 35 babies per year—female bats produce only one or two pups during the same time period. This means that the colony occupying your building, while growing in number, will not suddenly burgeon out of control over these summer months.

     There is, however, another consequence of bats being present in a building during bat maternity season (April 15th–August 15th). Any females giving birth at a particular site, and any female pups being born there, will be committed to producing the next generation in the same spot. It has thus become their go-to “maternity roost,” and as such, they will be tenacious in their attempts to regain access to it.

     This is where we come in, and this is what we are often able to do during bat maternity season to help manage and mitigate the problem and to begin to implement a solution—while at the same time not disturbing the roost site(s). 

     It is important to remember that when we perform a bat exclusion to a building or to multiple buildings on a site, we like to be able to offer a warranty that covers the entire building (or the entire site). In order to do this, we need to ensure that once the bats are safely and humanely excluded from existing roosting areas, not only are they unable to return to those specific areas, but they cannot gain entry to any other parts of the building(s). To do otherwise would simply relocate the problem and not resolve it. Remember, they are highly territorial, and if given the opportunity, they will re-enter a roosting site at new points if they are able.

     This means that while we cannot disturb the bats themselves during the course of bat maternity season, we are able to commence work on adjacent areas and adjacent buildings which are vulnerable to bat infestation once the exclusion process begins (after the season is over). This approach greatly speeds up the final resolution of the problem. It also offers the added benefit of containing the colony/colonies by limiting their spread from their current roosting sites. Here’s why failing to take these preventative measures can compound the problem.

     Bat physiology is incredibly similar to that of human beings. In fact, humans are the animal’s closest living relative (they are not our closest living relative, which is the chimpanzee). Every organ in our body is replicated in a bat—only the proportions are different. (If you were a bat, for example, your heart would be closer to the size of a basketball than it is to your fist.) Every bone in your body (including the tiny bones in your ears) exists within the body of a bat. Don’t be fooled by the wings—they are simply extremely elongated fingers with a skin membrane stretched between them. In fact, the generic Latin name given to the species is chiroptera, which translates as “hand wing.” As previously explained, they breastfeed their young, and while all are capable of walking upright, only one species—the vampire bat—does this. For all of these reasons and more, while they are currently classified as mammals, some scientists would like to see them upgraded from Chiroptera to the Primate order in classification.

Why Is This Important in the Context of Bat Maternity Season?

The answer is because bats are extremely similar to humans, not only in their biology but also in their behavior. Unlike most herd or flock animals, many scientists have concluded that the social organization of their colonies is not based upon the dominance of an alpha male but on the concept of care and respect for their oldest, youngest, and most vulnerable members. I personally have been observing colonies returning to their roost site for more than 20 years and have witnessed the younger, healthier animals giving preference to the older bats in the order in which they re-enter the roost. The assumption is that if a family of hawks or owls attacks the circling colony, the youngsters will have the best chance of evading them and surviving.

     Another similarity to humans is that when the juvenile bats are big enough and strong enough to “fly the roost,” they will seek to establish new colonies (“homes and families”) of their own close by. This process begins during the bat maternity season. Because different species are known to roost together, and each gives birth at slightly different times, the state of Florida allows considerable leeway both at the beginning and the end of the maternity process.

     In conclusion, not only can you take action to begin to resolve your colony infestation issue during the bat maternity season, but you probably should!

John Greenwood

Technical Consultant, Friends of Bats

     John Greenwood is the Technical Consultant for Friends of Bats, a Florida state-wide expert in bat exclusion and roost site prevention. For more information contact john@friendsofbats.com, visit www.friendsofbats.com, or call (888) 758-BATS (2287).