WildWatch Weekly

Eyes on the Colony: A Wild Bat Birth May Soon Make History at the Schwarz Barn

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The Sisterhood of the Schwarz Barn: Why the Bat Colony Is All Female

If you’ve tuned into the bat cameras at the Westmoreland Land Trust’s Schwarz Barn located in Greensburg, PA, link here: https://pixcams.com/wlt-schwartz-barn-bat-colony-cameras/, you may have noticed something fascinating — every bat in the colony is female. That’s not by accident. This is a maternity colony, made up entirely of pregnant or nursing female big brown bats (Eptesicus fuscus) that have come together for one important reason: to safely raise their pups.

In the spring and summer, female big brown bats form maternity colonies in warm, secure places like barns, attics, and bat boxes. These sites provide the stable temperatures and protection needed for successful pup development. Males, on the other hand, live solitary lives or in small bachelor groups during this time and are nowhere to be found around the nursery. By forming these female-only colonies, the bats can collectively benefit from shared warmth, social bonding, and reduced predation risk.

Each female will give birth to one or two pups in early summer, and the timing is carefully aligned with the seasonal abundance of insects, ensuring there’s plenty of food for the nursing mothers. Once the pups are weaned and ready to fly—usually about a month after birth—the colony will begin to disperse, and males and females will once again mix during the fall mating season.

This all-female gathering at the Schwarz Barn is a natural marvel of cooperation and maternal care, and thanks to our live cameras, we get a rare window into the secret world of wild bats. Keep watching — the birth of a pup could happen at any moment, and it would mark a truly historic moment in live wildlife streaming.

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Bat Pup Watch: What to Expect When a Big Brown Bat Gives Birth

The moment we’ve all been waiting for is nearly here — the birth of a big brown bat pup, live on camera at the Schwarz Barn. But what exactly should we be looking for? Unlike many other wild animals, bats give birth while roosting, often hanging upside down or clinging to a surface with their wings partially wrapped around their body. The birth is quick and quiet, and the newborn pup is immediately welcomed into a world unlike any other.

Big brown bats typically give birth during the daytime hours, while they are roosting. This is when the colony is resting, the environment is stable, and the mothers are undisturbed — ideal conditions for giving birth.

Births usually happen between late morning and early afternoon, but there’s no strict schedule. The key factor is that it occurs during the day, when the bats are not flying or foraging. At night, they’re out hunting insects, so daytime is when they’re safely settled in the roost, conserving energy and caring for their young.

So if you’re keeping watch on the Schwarz Barn bat camera, your best chance to witness a birth live will be during daylight hours, particularly late morning to mid-afternoon.

Big brown bat pups are born hairless, blind, and completely dependent on their mothers. They’re tiny — about the size of a jellybean — but they instinctively cling to their mother’s underside to nurse and stay warm. You might notice a mother grooming her pup or adjusting her position to help it latch onto a nipple. In the tightly packed maternity colony, females often roost shoulder-to-shoulder, so you may see several mothers giving birth or nursing within inches of one another.

Over the first few weeks, the pup will grow rapidly, developing fur and opening its eyes. While it remains too weak to fly at first, it will start to explore its surroundings by crawling and flexing its growing wings. By around 4–6 weeks of age, the pup will begin taking short practice flights inside the barn, preparing to eventually join the nightly foraging trips with the rest of the colony.

Seeing a wild bat pup’s birth and early development live on camera is a truly rare opportunity — perhaps even a first. Be sure to keep an eye on the stream; we’re on the verge of witnessing a hidden part of nature that has rarely been seen by human eyes.

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Listening in on the Night Shift: Monitoring Bats with BattyBirdNET-Pi

To gain deeper insight into the habits of the big brown bat colony at the Schwarz barn, we recently installed a BattyBirdNET-Pi acoustic monitoring system. This system is designed to capture and analyze ultrasonic bat calls throughout the night, giving us a clearer picture of when the colony becomes active and heads out to feed.

By tracking the volume and timing of echolocation calls, BattyBirdNET-Pi allows us to identify feeding patterns and better understand the nightly routines of these fascinating creatures. Over time, we hope this data will reveal not only when the bats leave and return to the roost, but also how changes in temperature, weather, or insect availability might influence their activity.

One of the most useful features of the BattyBirdNET-Pi system is the “Species Stat” page, which provides a graphical representation of acoustic activity over time. This tool allows us to visualize when the most bat calls are detected throughout the night, giving us a clear snapshot of peak feeding and flight activity. By analyzing these call volume patterns, we can track nightly trends, compare seasonal changes, and even detect shifts in behavior that might indicate environmental stress or changes in insect populations. It’s a powerful way to turn raw sound into meaningful data—and another step forward in understanding and protecting this important bat colony.

This non-invasive acoustic monitoring method helps us support ongoing conservation and research efforts by providing real-time insights into the health and behavior of the colony. We’re excited to see what this technology will uncover about the big brown bats at the Schwarz barn—and to share those discoveries with our community.

Link to BattyBirdNET-Pi at Schwarz Barn

​http://71.199.113.35:7001/​

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A Home of Their Own: Creating a Custom Bat Box with a Live Streaming View

Before we discovered the existing bat colony inside the Schwarz barn, we took early steps in the spring to support local bat populations by designing and installing a custom bat box on the barn itself. With guidance from local bat experts, we carefully followed best practices for bat box design and placement, ensuring it would provide the right conditions for shelter and warmth. Our goal was to create a safe, inviting space for bats to roost and potentially raise their young.

​What makes this bat box truly unique is the integration of two live streaming cameras—one positioned at the top of the box to monitor the roosting area, and another at the entrance to capture arrivals and departures. This dual-camera setup offers a rare, close-up view of bat behavior that’s never been done quite like this before. It’s an innovative approach that combines habitat support with real-time observation, helping us—and viewers around the world—better understand these nocturnal mammals.

So far, the bats have not moved into the box, as they seem quite content in their current roost inside the barn. However, bat experts we’ve consulted believe there’s still a good chance the box could be used in the near future. Once the young bats, or pups, begin flying on their own later in the summer, their natural curiosity may lead them to investigate the nearby box. It’s also likely that some of them will return to this location in future years to roost—potentially making this box an important addition to the local bat habitat.

We’ll be watching closely through the live cameras and our BattyBirdNET-Pi system, ready to document any activity in or around the box. Whether it happens this season or next, we’re excited about the potential for this innovative setup to contribute to bat conservation and education efforts in a meaningful way.

Link to Schwarz Bat Box Dual Camera Live Stream

​https://pixcams.com/wlt-schwartz-bat-box-cams/​

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Echoes of the Night: Understanding and Protecting the Schwarz Barn Bat Colony

As we continue to explore and learn from the big brown bat colony at the Schwarz barn, we’re reminded of how much there is still to discover about these often-overlooked creatures. With tools like the BattyBirdNET-Pi acoustic system and our innovative live-streaming bat box, we’re not only gaining valuable insights into bat behavior—we’re also creating opportunities for the public to connect with and appreciate the vital role bats play in our ecosystems. We’re excited to share this journey and hope it inspires others to support bat conservation in their own communities. Stay tuned as we listen, learn, and shine a light on the fascinating lives of these nighttime neighbors.

Watch the Schwarz Big Brown Bat Colony LIVE

​https://pixcams.com/wlt-schwartz-barn-bat-colony-cameras/​