Bats: Reproduction

Summary: How do bats make more baby bats? Let us count the ways! Join Kiersten as she discusses the various reproductive techniques bats use to make more bats.

 

For my hearing impaired listeners, a complete transcript of this podcast follows the show notes on Podbean

 

Show Notes:

“Bats in Question: A Smithsonian Answer Book,” by Don E. Wilson

Music written and performed by Katherine Camp

Transcript

(Piano music plays)

Kiersten - This is Ten Things I Like About…a ten minute, ten episode podcast about unknown or misunderstood wildlife.

(Piano music stops)

Welcome to Ten Things I Like About… I’m Kiersten, your host, and this is a podcast about misunderstood or unknown creatures in nature. Some we’ll find right out side our doors and some are continents away but all are fascinating. 

This podcast will focus ten, ten minute episodes on different animals and their amazing characteristics. Please join me on this extraordinary journey, you won’t regret it.

I apologize for missing last week, listeners. The holidays snuck up on me and I just didn’t have time to write, record, edit, and post before Christmas was upon me. Let’s get back to bats!

The fourth thing I like about bats is making more bats! Chiroptera reproduction is interesting and diverse. Microbats and Megabats are mammals, so they give live birth and nurse their young with milk, but we’re going to take a closer look at the reproductive cycle of some of the specific species of bats in this episode. 

As my loyal listeners know, I earned my Master’s of Science in Animal Behavior by studying the breeding behavior of the Tri-colored Bat, Perimyotis subflavus. I chose to study the breeding behavior of this particular bat because they are heavily impacted by White-nose Syndrome, a disease that impacts the hibernation behaviors of bats that overwinter in caves that remain around 55 degrees or cooler throughout the year. Many of the caves on the East coast of the United States fit this bill. I will be talking more about this problem in a future episode. The reason I wanted to study the breeding behavior is because we did not have a record of how these bats reproduced. If their numbers fell so low that we needed to intervene to help save the species from extinction, it was essential that we knew how they reproduced so we could offer everything they needed in a captive setting.

So, off I went with my husband in tow to sit for hours at a time in a dark cold cave at 2am to record the behavior of hibernating Tri-colored Bats. What did I learn? We discovered that in this cave, the Tri-colored Bat males will seek out females during their hibernation periods and mate with them. Yes, that’s right these little boogers mate with the females while they are sleeping! We were shocked! But it is the optimal time to mate with females without having to expend excessive amounts of time and energy vying for their attention. 

I agree that it sounds terrible. Not very nice at all. No consent from the females, but it works for this species of bat. The males and females go their separate ways as soon as the winter season passes so the males have no chance to breed later in the year. The female’s body stores the sperm until it is needed. When the time is right, the sperm will fertilize the egg and she will become pregnant. 

Many species that hibernate in caves breed during the fall season as males and females are swarming into the caves. For these species there are two paths to fertilization. One I just talked about, where the female stores the sperm in her reproductive tract until spring. Another path is immediate fertilization. Long-fingered bats from the Old World practice this method. The females and males breed in fall and fertilization happens immediately, but development of the fetus is slowed during hibernation so that the female will be ready to give birth come spring.