BCM offers a wide range of hibernacula services including (but not limited to):


Preparing harp traps at an anthracite coal mine portal

Harp Trapping
Harp trapping is limited to fall and spring, when bats are entering and exiting their hibernacula. Fall is preferred because it is fairly well known when specific species will re-enter these sites, so trapping for specific species, (the Indiana bat) can be accomplished much more easily (cheaper). Harp trapping has very limited applications. It is mainly used at sites where internal surveys are not safe and then only for determining species present during sampling. Some bats that swarm a site may not actually hibernate there, they may just be investigating the site as a backup in case their primary hibernacula inaccessible or unsuitable. Costs vary depending on location, size, number of portals, and number of trap nights. All state and federally listed species is professionally photographed for the record.


Night Vision
Our night vision equipment unintrusively videotapes the activity (or lack of activity) at any particular site. This equipment is deployed where traditional trap techniques are physically impossible. Using this equipment, we have been able to show a lack of swarming activity near abandoned mine sites despite bats bing captured nearby in mist nets. Used in conjunction with mist netting or harp trapping, the night vision tapes produce unshakable proof of animal activity during sampling.


Mine Closure
After surveys are preformed, heavy equipment can be brought in to close the portal, and slumping of fill can lead to high long term maintenance costs. This process obscures mine openings and greatly increases the risk of a housing development or shopping mall being built on this less than ideal area.



Schooner Cave gate construction

Gate Building
Gates are the economical and responsible long term solution to controlling mine entrances. Our gates are bat friendly and as people proof as possible. Gates are constructed according to American Cave Conservation Association standards and our gating project manager is ACCA certified. These two projects at privately owned Seawra Cave and Mount Rock Cave were built for approximately $3,500 each, with recreational access controlled by local chapters of the National Speleological Society. (Access policy to any site is purely in the hands of the landowner, not BCM.) We at BCM have experience with fund raising for these projects and may be able to help in financially strapped cases where state and federal protection priorities are involved.


Mt. Rock Cave gate

Another major gating project we are involved with is the re-gating of a historic Iron Mine in western CT, this site is CT's largest hibernacula. The current gate setup has been repeatedly breached and is at the top of the states critical habitat protection priority list. The site has four vertical shafts and two horizontal openings. The vertical shafts are the weak link. These openings will require that full bat friendly cage structures be built over the openings. Many agencies and organizations are contributing to the effort to protect this site far into the next millennium. Between contributed services and financial grants this projects budget will crest $70,000. See the results of our other recent gate projects: Mill Grove Audubon Mine (PA), Sanders Cave (IL), and Roxbury Mine (CT) in ProjectCentral.




Sewra Cave gate

Gate Inspection/Design Services
If your agency or organization needs to have a expert on hand to offer advice and/or critique another contractors work we have ACCA certified gate experts available to fill your needs.






Closeup identification of possible Indiana bats

Internal Surveys
While bats are hibernating, stable sites can be carefully entered and the bats are then identified and counted. This is the best way to find out number and type of bats that are hibernating in the site. With over 2,000 cave visits to over 650 separate sites in the United States and Mexico, be assured that no reasonable hibernacula is inaccessible to our surveyors. If possible bat concentrations and weather data are indicated on a site map so yearly changes can be tracked. Our observations will suggest what species the site is suitable for (if any). If no map exists BCM has over six years of underground survey experience to draft an accurate representation of your site if needed. All federally endangered species is professionally photographed for the record. All of our surveyors have participated in National Cave Rescue Commission courses and are trained in modern vertical techniques. See recent related projects in


Temperature Monitoring


Sewra Cave bat survey


Abandoned flooded iron mine bat survey

Different bat species prefer different temperature ranges. Hibernacula can be managed (via entrance modification) to achieve specific temperature ranges. Using temperature data, entrance modifications can be made to achieve ideal temperatures for hibernating bats. We only advocate temperature modification in manmade sites (mines, railroad tunnels, and aqueducts). Monitoring is also useful at any site where long-term management plans are in effect. Background data should already be on file in case entrances are accidentally or naturally opened or closed. This is a long term but relatively inexpensive project that requires BCM to place remote sensors at strategic locations for months at a time.

Hibernacula Projects
Mines - Caves - Aqueducts - Railroad Tunnels

Crisis mine management? No problem. Due to current regulations, mines cannot be closed without a bat survey taking place, and the US Fish and Wildlife Service may request sampling at abandoned mine portals before they are impacted with new construction alignments. Surveys can only be done at restricted times of the year, and preplanning is a must. Previous clients include the PA Department of Transportation, PA Turnpike Commission, and WV Department of Transportation. Contact us with your project scope for free consultation.


Bat Conservation and Management, Inc. Carlisle, Pennsylvania (717) 241-ABAT