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Grants - Section 6 Traditional Grants to States

Missouri 2008 Grant Proposal

PDF Version (23 pages)

Relationship between Forest Management and Summering Indiana Bats


Below is the Project Statement, Objectives, Expected Results and Benefits, and Project Approach. Go here for the complete 23-page PDF version of the project proposal.




The Indiana bat (Myotis sodalis) is listed as endangered under the Endangered Species Act and despite aggressive protection of bats at their winter cave hibernacula sites, the abundance of the species has continued to decline (Clawson 2002).  Habitat loss or modification from development or timber harvest at their summer forested roost sites is often cited as contributing to the decline.  Worries about summer habitat quality have resulted in dramatic modification or restriction of active timber management on many public forests where Indiana bats are known to summer.


While responsible forest management is considered suited for maintaining Indiana bat summer habitat, information on the effects of forest management on bat populations is limited (USFWS 2007).  Current timber management recommendations to benefit Indiana bat summer habitat focus on creating or retaining snags for roost trees and creating canopy gaps as foraging areas.  Proper spatial arrangement of these habitat components is usually inferred from distances moved from capture location to roost tree and between roost trees. 


Additionally, even if responsible forest management in areas inhabited by summering Indiana bats is considered acceptable (possibly beneficial) to the population, direct effects ("take") of management on individual bats is a contentious issue.  Three cases have been documented in which a roost occupied by Indiana bats was felled (USFWS 2007).  In all cases some bats were injured or killed, but other bats were seen exiting the felled tree and in one case adult females that survived apparently returned and retrieved non-volant young.  Timpone (2004) documented Indiana bats appearing to abandon a primary roost in response to removal of selected trees within 100m of the roost tree.  However, this abandonment occurred during the last summer of study so it is unknown whether bats utilized the roost in subsequent years and this was only one instance.  Because of the possibility of direct harm to bats, seasonal restrictions on management activity (i.e., cutting while bats are hibernating) are often suggested (USFWS 2007).


Current work on estimating relative abundance or density is based on capture rates, detections/unit effort, or capture/recapture.  Acoustic monitoring is often presented as detections per unit effort, but realistically only relays presence or non-detection information; until recently the probability of a bat being present but undetected was not included in studies (Amelon 2007).


Studies in 2001 and 2002 at Deer Ridge Conservation Area (DRCA, Figures 1 and 2), owned by MDC, used radio telemetry and ANABAT detectors to document the largest summer aggregation of Indiana bats known in Missouri (Miller 2003, Timpone 2004).  In 2003, with input from Rick Clawson (Team Leader of the Federal Recovery Team), a forest management program was begun on the area.  Small clear cuts, uneven aged management with small group openings, and retention of snag trees were the dominant practices.  This management was designed to maintain or improve 2001-2002 levels of Indiana bat use and habitat availability while achieving traditional forest and other wildlife objectives.  Limited pilot work in summer 2007 indicated that a significant population of Indiana bats still uses DRCA, but increased use of the most recently managed areas was not documented, though bats did roost in trees that were girdled in 1997 or 1998.  An evaluation of the relationship between forest management and Indiana bat summer roosts, foraging activity, or population would provide key pieces of information to assess the effect of treatments.  Unfortunately, differences in methods and area coverage between the previous studies and our proposal reduce the utility of considering the previous work as pre-treatment data.  Any work at DRCA would be documenting Indiana bat population trends and area use in the presence of managed forests, without being able to infer any changes from pre-management conditions.


There are two other Conservation Areas in northeastern Missouri (Clark County, Figure 1) that are excellent potential study sites for examining relationships between forest management and summering Indiana bats.  Charlie Heath Memorial (CHCA, Figure 3) and Fox Valley Lake (FVCA, Figure 4) CA’s both include bottomland and upland forest and appear to be very good Indiana bat summer habitat.  However, while there is high potential for Indiana bats to use these sites, presence has not been confirmed.  MDC has not conducted forest management on these areas since acquisition.  Timber inventory has been completed on FVCA and cutting is scheduled to begin in September, 2008.  This presents the opportunity to conduct work at FVCA during the summer of 2008 to determine whether and how Indiana bats are using the area.  While the one year will not provide range of variation of pretreatment data, planned management may provide the opportunity to investigate direct impacts of logging on individuals or specific maternity colonies.  Forest inventory and subsequent management is scheduled to begin at CHCA in 2011.  This provides an opportunity to conduct 3 years pretreatment data collection (this project proposal, which address Phase 1 of the overall planned project); with the intention that post treatment studies will be completed after the harvest (Phase 2, under a separate proposal).  Comparisons between pre- and post- treatment use by Indiana bats will allow strong inferences between forest management treatments and effects on use by Indiana bats on one study area.



  1. Determine whether Indiana bats are present on Charlie Heath Memorial CA and Fox Valley Lake CA  – if not documented in an area then priority will be shifted away from that area.
  2. Determine probability of patch occupancy and probability of detection for Indiana bats on Charlie Heath Memorial CA, Fox Valley Lake CA, and Deer Ridge CA and develop predictive occupancy and habitat use models based on roost, site and landscape covariates. 
  3. Map roost trees, associated flight corridors, and foraging areas for Indiana bat colonies (using triangulated positions of active bats) at Charlie Heath Memorial CA and Deer Ridge CA. 
  4. Attempt to identify primary roost locations at Charlie Heath Memorial CA, Fox Valley Lake CA, and Deer Ridge CA.  If found, track the activity/fate of individual maternity colonies through time by conducting aerial and primary-roost-site searches and estimate use of identified sites.  Track use and suitability of identified trees over time.


The objectives outlined in this project will benefit Indiana bats by evaluating the effects of forest management on the quality of habitat and relative amount of use associated with common forest management activities.  Information from this project will assist forest management decisions on both public and private land in Missouri, potentially contributing to best management practices for forest management in the presence of summering Indiana bats.  Timing, spatial arrangement, and type of forest management are all important considerations in managing for Indiana bats. 


To date, in the absence of credible information on the relationship between Indiana bats and forest management, the presence of Indiana bats has been used as a reason to restrict active forest management.  Active forest management is proceeding in northeastern Missouri and information from this project will be useful in informing and potentially defending that management.  Producing useful data from these few locations in northeastern Missouri could encourage other agencies (USFWS, other state wildlife agencies, etc.) to conduct similar research throughout the Indiana bats range. 


This first phase of the larger project will produce important information regarding Indiana bat use of areas with and without recent forest management.  Additionally, in conjunction with Phase 2 of the project this work will track a population of bats on an unmanaged area to provide baseline information through the active management and immediate post-harvest timeframe.



This will be a long-term, two phase project designed to evaluate habitat use by Indiana bat both spatially and temporally as affected by forest management.  Phase 1 will be conducted from May 2008 through April 2011 (this grant) and Phase 2 will cover years 2012 through 2015.  Project activities outlined in this proposal will require temporary staff to be contracted through the University of Missouri to collect data during the maternity period (May through August).  Activities will be coordinated by permanent staff members of Forest Service and MDC. 


Click here for the complete 23-page PDF version of the project proposal


Back to "2008 Section 6 Traditional Grants" page


Last updated: April 14, 2015