In an effort to support local bat populations, the University of Pennsylvania School of Veterinary Medicine's (Penn Vet) Wildlife Futures Program (WFP) has facilitated the design and construction of a collection of wooden bat boxes to be installed in campus parks.

The bat population of Pennsylvania has been on a sharp decline since 2008, due mainly to white-nose syndrome, a fatal fungal disease that targets hibernating bats. In the case of the Little Brown Bat, the population has declined by more than 90%, leading to its designation as an endangered species and sparking statewide conservation efforts.

In collaboration with Penn Sustainability and Penn Facilities and Real Estate Services, Penn Vet’s WFP is combating bat population decline within the urban ecosystem of Philadelphia by establishing a safe breeding environment for colonies of Little Brown bats and Big Brown bats. As part of the initiative, five wooden bat boxes — each of which can hold up to 200 bats — were created in the Weitzman School of Design Fabrication Lab. Once installed in outdoor spaces across campus, the boxes will provide a safe space for hibernation, breeding, and maternity roosting, addressing the lack of wooded areas and caves that bats traditionally prefer for housing.

“Bats are so ecologically important,” said Julie Ellis, PhD, co-director of the WFP. “They eat mosquitoes and insects that negatively impact agricultural production, and several bat species worldwide serve as important pollinators. But in urban ecosystems, bats often do not have access to safe places to form breeding colonies and raise their young. As a result, they end up living in buildings or in the attics of people’s houses, from which they are usually quickly evicted. Our bat boxes are designed to mimic tree habitat and support the daily needs and overall health of bats.”

The WFP initiative to address bat population decline in Philadelphia was kickstarted by the passion of Penn undergraduate student Nick Tanner, a double major in linguistics and math, who wanted to find a way to incorporate bats into Penn’s Climate Week – a week-long series of events taking place on campus from October 14-18 that encourages the University community to learn about climate change. Having grown up with cavers as parents, Tanner developed a strong affinity for bats and their ecological significance early on in life.

After reaching out to Simon Richter, Class of 1942 Endowed Term Professor of German Studies and initiator of Climate Week at Pennwith the idea of introducing bat boxes to campus, Tanner was connected with the WFP to help his concept take flight.

Jointly, Tanner and Penn Facilities and Real Estate Services Assistant Landscape Planner Daniel Flinchbaugh built the university’s suite of wooden bat boxes using design plans provided by the Pennsylvania Game Commission.

“Cities are their own ecosystem,” Tanner said. “Rather than trying to make a city ecosystem be equivalent to a forest ecosystem, we need to make the city of Philadelphia co-habitable for people and wildlife. Creating bat boxes is a straightforward way to support bat health and restore some of the habitat we have lost.”

Each spring, bats arrive in the Philadelphia area to mate and reproduce before moving on to other geographical areas later in the year. This fall, a portion of the bat boxes will be installed at Kaskey Park. In early 2025, several boxes will also be installed at Penn Park. The location of both parks capitalizes on the established bat migratory pathway along the Schuylkill River. Starting in spring 2025, the local bat population will have access to the new maternity spaces for birthing and raising their young.

“The bat box project is a great example of what Penn does best,” said Penn Sustainability Director Nina Morris. “By connecting a passionate student with a program dedicated to caring for wildlife populations, we can increase our community’s understanding of the importance of protecting bats, while adapting our campus to do our part in preserving local populations.”

The WFP’s bat-focused Climate Week initiative represents a significant step towards enhancing urban biodiversity on Penn’s campus. According to Ellis, protecting wildlife biodiversity is a natural extension of the values held by both Penn Vet and veterinarians in general.

“Veterinarians are dedicated to animal care and passionate about biodiversity in general,” Ellis said. “It is only natural that they would play a role in protecting the health of wildlife, which in turn protects the earth’s biodiversity. Veterinarians bring expertise to the conservation table that’s badly needed.”

In addition to the creation of campus bat boxes, the WFP Climate Week initiative will include an in-person event, titled “Bat Bonanza.” Planned for October 15, the event will take place in the Climate Week tent on College Green from 5-7 p.m. Event attendees will have an opportunity to hear from WFP postdoctoral researcher Axel O.G. Hoarau, PhD — whose doctoral thesis centered on viruses in bats — learn about bat facts through posters created by WFP communications coordinator Brooke Ezzo, and help stain the exteriors of the new boxes.