a mother bat and baby bat

Bat Maternity Season – What You Need To Know

Bat Maternity Season has begun! The upcoming weeks and months are crucial for the survival of bat mothers and their babies, making it vital for us to be aware of their vulnerability and the importance of protecting these remarkable creatures. In this blog, we’ll answer the top questions about bats and their pups, like “When do bats have babies?” “How do bats give birth?” and “What is a maternity colony?”. Keep reading to find these answers!

What Is a Bat Maternity Colony?

A maternity colony is a group of pregnant bats that come together during the reproductive season in Spring to roost together. They live together in these roosts for a few weeks before they give birth and stay in the colonies until the pups are strong enough to leave the roost. These roosts provide warmth and protection for the pups. Attics are particularly attractive to bats during this time, offering a safe space to raise their young.

bat colony roosting in bat maternity season

How many bats are in a maternity colony?

The number of bats living together in a maternity colony varies depending on the species. Here are the average figures for three of the most common bats in the US:

BAT SPECIES LOCATION SIZE of MATERNITY COLONY
Little Brown Bat (Myotis lucifugus)  U.S. + Canada 2 - <300
Big Brown Bat (Eptesicus fuscus) North America, Central America, the Caribbean 5-700 (average <100)
Mexican Free-tailed Bat (Tadarida brasiliensis) U.S., Central America, South America ≤15 million

The largest maternity colony in the world

As shown in the figures above, Mexican free-tailed roost in much larger numbers than other species. The world’s largest maternity colony is in Bracken Cave, San Antonio, Texas. This site hosts a maternity colony of Mexican Free-tailed Bats that can number over 20 million bats! The bats emerge from the cave each evening in massive numbers to hunt for insects. This immense maternity colony plays a vital role in pest control, consuming vast quantities of agricultural pests and benefiting local ecosystems and farmers. 

Another site famous for its enormous maternity colony is Congress Avenue Bridge in downtown Austin, Texas. This is home to the world’s largest urban bat colony, and it’s estimated that bat mothers raise around 750,000 pups each year at this site. 

How Long Does Maternity Season Last?

The timing of bat maternity season varies depending on the species and climate. In the United States, it typically starts in mid-April and can extend until mid-August. Warmer states tend to have an earlier maternity season, while cooler states experience it slightly later.

Bat Reproduction Cycle

Bats have a unique reproductive cycle that has fascinated scientists for decades! Unlike other mammals, bats have delayed fertilization. Although the bat mating season is often in the fall months, the female bats store sperm until after hibernation. So, in the Spring, the sperm is released, and fertilization occurs. The gestation period for bats varies by species but typically lasts between 40 days and six months, and at some point during this time, the female bat will join her maternity roost and prepare for the birth of her pup. 

a mother bat and baby bat

How do bats give birth?

Bats do not lay eggs; they give birth like other mammals and usually give birth to just one pup. When the time comes to give birth, the mother bat hangs upside down, her natural resting position, and delivers in this position, assisted by gravity. The pup emerges feet first, which is unusual among mammals but helps prevent the pup from falling. Immediately after birth, the pup instinctively uses its strong feet and claws to cling to its mother’s fur.

After the birth 

Newborn bat pups are born blind, hairless, and dependent on their mothers. The mother provides constant care, nursing the pup and keeping it warm. In many species, the mother will carry the pup with her while she forages for food until the pup is strong enough to be left at the roost with other pups and bat mothers to watch over them. Bat pups grow rapidly, with their eyes opening within a few days to a few weeks, depending on the species. They develop fur, grow stronger, and eventually learn to fly at around three to four weeks old. So, on average, bat mothers and their pups will stay in the maternity roost for around 4-6 weeks after the birth. 

A tiny baby bat sat on a finger

Bat Removal Laws During Maternity Season

Many states specify a time frame during which wildlife protection laws are strictly enforced to safeguard bat populations and their vulnerable pups. For example, in Texas, the protection period for bats, particularly Mexican Free-tailed Bats, typically runs from March 1 – August 31. In Florida, bat maternity season runs from April 15 – August 15, during which it’s illegal to block bats from their roosts. In Oregon, state guidelines typically restrict bat exclusion from May 1 to August 31. In Colorado, bat maternity season spans from June 1 to August 15. Again, any exclusion or removal of bats from buildings is prohibited during this period to prevent disturbance or harm to the mothers and their pups. Most states have laws specific to the species common in that region, so if you need to arrange a bat removal due to bats in your attic, you should check local legislation before performing any bat removal work. These regulations ensure that bats can safely raise their young, contributing to the preservation of bat species and the stability of our ecosystem. Always check with local wildlife agencies or a reputable bat removal company for specific regulations in your area to ensure compliance and protect these important creatures.

Protect Bats at Any Time

Bats play a crucial role in our ecosystem, providing services that otherwise would cost millions of dollars, including pest control, pollination, and seed distribution. Sadly, habitat loss and diseases like white-nose syndrome contribute to declining bat populations. Disturbing a bat roost during the maternity season could result in hefty fines and, more importantly, in the loss of bat pups, further endangering the species. Let’s appreciate and protect these remarkable creatures during their maternity season to ensure a healthier and more balanced ecosystem. If you’re concerned about bats in your attic over the summer months, contact your local bat removal specialist, who will be able to give you expert advice on how to deal with your bat infestation in a lawful way that protects the bats as well as the health and wellbeing of your household. Get Bats Out is a nationwide bat removal company with local technicians covering all U.S. states. With our expert skills and local knowledge, we are ready and able to help. Reach out to us today if you have any concerns or questions.

A bat colony on a wall in a house before bat removal work is done

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Your Local Bat Removal Expert,

Michael Koski

Get Bats Out Owner and President Michael Koski

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