Hope for Pennsylvania’s Bats – Cal Butchkoski’s Legacy

By Merlin Tuttle
6/18/21

Calvin Butchkoski wasn’t privileged to attend graduate school. In fact, he never even took a course in bat biology while earning an associate degree in wildlife technology at Penn State. Yet, he became his state’s all-time leader in bat conservation. His amazing career is a testament to the power of following one’s passion while caring for both bats and humans.

 

Unable to find employment as a biologist, he served in the Marine Corps for three years after college. Finally, in 1982, he was hired as a biology technician by the Pennsylvania Game Commission where he assisted in studies of wild turkeys, bears, and even packrats for two years. He didn’t discover his true passion until assigned to work with bat expert, Dr. John Hall.

Despite a late start and lack of formal training, mostly self-taught, Cal quickly became one of America’s foremost bat conservationists. In fact, he led Pennsylvania to become a national model. His achievements include key bat house discoveries, the establishment of America’s first citizen science bat counts, protection for the state’s most important hibernation sites in caves and mines, special training for hundreds of state and federal employees, and highly successful public education campaigns.

 

Cal led early research on the most appropriate bat house designs for Pennsylvania and helped homeowners solve nuisance problems caused by too many bats attempting to live in walls and attics. His bat house alternatives saved thousands of bats from extermination. And homeowners often became citizen scientists volunteering their help with annual emergence counts.

Cal enjoying the company of an inquisitive packrat. He is a natural-born animal lover and outdoorsman who cares about all wildlife.

When an introduced fungus began killing millions of bats with a disease called white-nose syndrome (WNS) in 2011, Cal’s private citizen emergence counts became critical in documenting bat status trends needed to justify federal and state funding to protect and restore Pennsylvania’s formerly most abundant bats. Most of the state’s WNS survivors now live in Cal’s bat houses.

 

His citizen emergence counts have substantially expanded. They now include several states in a project known as The Appalachian Bat House Count. The project still relies on Cal’s original database. And the state of Pennsylvania even provides its citizens with Cal’s latest bat house design gratis. This deluxe model has an outer shell of aluminum with 14 replaceable wooden roosting chambers. They’re even installed at no charge. Costs are covered by federal and state grants.

 

Cal’s introduction of bat houses provided a firm foundation for public education, but his efforts and successes went far beyond. When he began his work in the 1980s, Americans widely believed that most bats were rabid and dangerous. In 1993, he played a lead role in producing one of America’s first films, Season of the Bat, that allayed fears and promoted bat values and conservation needs. It was a classic in its time.

 

His enthusiasm for bats spilled over to staff at the Canoe Creek State Park where he provided programs and trained staff. He also convinced the state’s Wild Resource Conservation Fund managers to purchase and protect a long-abandoned church nearby which harbored a nursery colony of 10,000 little brown myotis (Myotis lucifugus). He then hung sheets of plywood in the attic, creating ¾-inch-wide spaces which enabled the colony to double in size. Soon, park naturalists, trained by Cal, were leading popular bat watching events for visitors.

Cal helping graduate student, Lisa Williams, with early research on the preferred roosting temperatures of little brown myotis.
Cal explaining one of his occupied bat houses.
Little brown myotis in one of Cal’s early bat houses.
Canoe Creek State Park naturalist, Kerry Estright-Pruznak, explaining the impressive dawn return of more than 10,000 little brown myotis to park visitors.

Sadly, with the arrival of white-nose syndrome, numbers of bats plummeted, some species declining by 90%. Only a few hundred park bats remain. Nevertheless, Pennsylvania’s bats are now showing signs of gradual recovery, greatly aided by Cal’s early efforts.

 

Cal retired from his full-time bat biologist position at the Game Commission in 2014. But his personally trained and equally passionate successor, Greg Turner, says survivors are “flocking to Cal’s bat houses.” In fact, he reports the only summer colony of endangered Indiana myotis (Myotis sodalis) known to remain in Pennsylvania is living in one of Cal’s houses. Greg is also tracking bat survivorship at mines where Cal protected, and sometimes experimentally altered, entrances to provide lower, more stable temperatures needed for bat hibernation.

Thanks to Cal’s personal training efforts, state Bureau of Mine Reclamation and federal Office of Surface Mining staff learned to survey mines for hibernating bats instead of simply sealing them shut as safety hazards. Pennsylvania’s abandoned mines are now protected with hundreds of bat-friendly gates.

 

He also conducted important research, radio-tracking bats to discover key habitats and altering unused mines to create invaluable hibernation sites. Full documentation of impacts may take decades. But Greg is already reporting significant progress, demonstrating key potential for adapting currently unused mines to become potential havens for major bat recovery.

To avoid being caught in early fall storms, many Pennsylvania bats enter hibernation in late September or October. Then they must survive till spring on stored fat. During hibernation, their body temperatures fall to that of the chosen cave or mine wall. Ideally, they need to find winter roost temperatures between 37 and 43° F (3-6° C) where there is little or no risk of freezing. Such sites require the least expenditure of stored fat, but very few mines or caves provide these ideal conditions in Pennsylvania. Without chimney-effect airflow between entrances, combined with large volumes below, for cold air trapping and storage, mid-latitude caves and mines are too warm for hibernation. Some bats travel all the way to Kentucky to find exceptionally large (most stable), cold-air-trapping caves.


Bats living in ideal summer roosts, especially those nearest good feeding and hibernation sites, save energy by reducing travel costs. Such bats are better prepared to survive unusual threats, such as extreme weather, human disturbance, or fungal infection that can force them to wake up too frequently. A single extra arousal can cost a month’s supply of fat.

Surviving six months of annual hibernation is critical to Pennsylvania’s traditionally most abundant bats. This is a key factor in losses from the invasion of a foreign fungus. The resulting disease causes hibernating bats to wake up at as much as twice the normal frequency. They simply starve before spring.


Successful alteration and protection of huge, hard-rock mines are likely to be the most important actions we can take to help bats recover from WNS-caused losses. A single large mine can provide space for up to a million bats, but temperatures must be just right.

The Casparis limestone mine, in southwestern Pennsylvania, has outstanding potential. It was abandoned in the 1950s, subsequently viewed only as a public safety hazard. It had four entrances. The two largest ones were at its lowest level, preventing entrapment of cold air needed for bat hibernation. Its tunnels were large but too warm and variable to meet most bats’ needs.


The mine was slated for permanent closure. But Cal recognized a potentially major opportunity to create a hibernation site for several bat species, including the endangered Indiana myotis. He proposed completely sealing the lowest entrance, one upper entrance, and the lower three-fourths of the tallest, middle entrance, where a bat-friendly gate was provided. This permitted continued entry of bats and cold winter air, which could be stably trapped in spacious tunnels below, hopefully creating ideal hibernation opportunities.

The work was conducted in the summer of 2005. By 2007, a winter survey reported a four-fold increase in bats, including the first Indiana myotis. Given the slow reproductive rates of bats, it may take decades to fully appreciate the value of Cal’s many experiments.

Nevertheless, his already groundbreaking achievements have laid a firm foundation for optimism in Pennsylvania and beyond.


Perhaps most importantly, his enthusiasm and friendly personality are contagious. He’s won the support of countless volunteers, made his long-time supervisor, Jerry Hassinger, a proud partner, and inspired and mentored outstanding professionals, including his well-trained successor, Greg Turner, who had this to say:


“Cal always saw the whole picture. He was both an innovator and an inspiring mentor, and I was lucky enough to have him as mine when I was starting my professional career. I am now applying what he taught me as we strive to help our bats recover from white-nose syndrome, the greatest challenge yet faced.”

Pennsylvania’s bats continue to benefit from Cal’s now volunteered assistance.

Cal radio-tracking endangered Indiana myotis to find their most important habitats.
Cal calibrating a newly installed data logger which will monitor annual temperature fluctuations in an abandoned limestone mine protected for hibernating bats.
At the Casparis Mine, a rotary blast hole drill was used to drill holes for the 50,000 pounds of explosives detonated in a series of blasts into sandstone used to back-fill mine entrances, not a small job!
Two of the Casparis Mine’s four entrances. The smaller of these was subsequently sealed while the uppermost fifth of the taller one was left open, fitted with a bat-friendly gate. Two entrances aren’t visible. The lowest of those was sealed, the upper one fitted with another bat-friendly gate, permitting chimney-effect air flow between the gated openings with cold air trapped behind the completely and partially sealed entrances.
The same view of the Casparis Mine after closure with gate barely visible under construction. The large rocks were intentionally left exposed to create woodrat habitat.