Scoping Notice: The Colorado River Valley Field Office (CRVFO) of the Bureau of Land Management (BLM) is completing an environmental assessment to consider implementation of management actions, including targeted seasonal closures at cave and abandoned mine sites that contain hibernating bats, to reduce the risk of spread of white-nose syndrome (WNS) in bats.  The scoping notice and comment period provides an opportunity for public participation on proposed management actions prior to a decision being made by the BLM Field Manager. 

Proposed Action: Following policy direction from BLM’s Colorado State Office, as outlined in BLM Instruction Memorandum No. CO-2011-006, the proposed action is to identify and establish targeted, seasonal closures at sites located on BLM lands in the CRVFO with significant populations of hibernating bats that remain physically accessible to the public during the bats’ hibernation period. For features having important bat resources the closures are proposed include exemptions for persons conducting search-and-rescue operations, approved WNS related monitoring, research, under-ground abandoned mine surveys and closures, and those authorized for activities granted by the Mining Law. Additionally, recreational caving permits may be made available in some areas where bat hibernation disturbance can be demonstrated to be minimal. BLM proposes to require decontamination procedures of all parties (following the latest U.S. Fish and Wildlife Service protocols).

 

Potential Range of Alternatives: An appropriate range of alternatives will be considered based on scoping comments and internal review. Initial internal review of the action and available information have indicated that the range of alternatives may include closing caves and abandoned mines with documented bat use until the risk of WNS contamination can be fully determined. 

 

The BLM Field Manager will decide whether or not to implement the proposed action or another alternative developed in response to scoping and environmental analysis. In addition, the BLM Field Manager will determine if additional mitigation measures will be required. 

 

Contact Information: The CRVFO has limited information on where bats hibernate, roost or congregate.   So the CRVFO is interested in acquiring additional information on bat use of cave and abandoned mine sites as well as comments on the proposed action. Please submit comments by June 3, 2011.  Send your written comment to:

 

 

For further information contact Brian Hopkins at (970) 876-9073 or visit Colorado BLM’s website:             http://www.blm.gov/co/st/en/BLM_Programs/recreation/White_nose_Syndrome.html       

Background: Bats play an important role in controlling insects, some of which are agricultural pests or vectors for human disease. Almost any insect that is active at night can be food for a bat. An individual bat can eat its body weight or more in insects every night. 

 

Eighteen species of bats are known to occur in Colorado. Not all 18 species are found within the CRVFO. However two species [Townsend's big-eared bat (Corynorhinus townsendii pallescens) andfringed myotis (Myotis thysanodes)] are documented as occurring in this Resource Area and are listed on the BLM Colorado State Director’s Sensitive Species List. The Townsend's big-eared bat is also a state species of special concern. 

 

WNS is a newly discovered fungal disease that has killed more than one million bats across the northeast and mid-Atlantic United States during the past four years and continues to spread westward unchecked.  WNS has not been discovered in Colorado but its introduction is feared to have similar consequences. Bats with WNS may exhibit a white fungus that is found around the muzzle, ears, or wings of affected individuals.  Other bat symptoms include moving to the entrance of the caves or coming out of the caves and flying around in the middle of the day during their normal winter hibernation period.  Although it is normal for bats to occasionally awaken from their winter hibernation, they are not equipped to withstand the drain on their fat reserves from awakening more frequently during the winter months when food is not available. This uncharacteristic behavior is thought to be caused by the irritation of the fungus. 

 

Bat to bat transmission of the fungus (Geomyces destructans) has been documented in lab conditions and the geographic pattern of spread appears to support lab findings. It is also possible that other unknown agents associated with WNS are spread bat to bat. Aspects of the geographic spread suggest that humans may also transmit WNS from infected sites to clean sites. This kind of spread is most likely occurring from clothing and equipment that are not properly cleaned and decontaminated between sites. Formal testing of human-spread WNS is ongoing. Because of the devastating effects of WNS, it is critical that people assume responsibility for preventing the spread of WNS.

 

In general, bats are very reclusive. Thus the BLM and other agencies have limited knowledge of where bats hibernate and roost in Colorado. Bats that hibernate and roost in caves or mines where cool, moist conditions are favorable to the Geomyces destructans fungus are most susceptible.

 

The fungus currently is found in caves and mines that have been visited by hundreds of people during the past three years, yet there have been no reported human illnesses attributable to it.  However, because scientists are still learning about WNS, we do not know if there is a risk to humans from contact with affected bats.