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COLORADO PARKS & WILDLIFE 2300 S. Townsend Avenue • Montrose, Colorado 81401 Phone 970 252 -6000 • FAX 970 252 -6053 wildlife.state.co.us • parks.state.co.us Guidelines for bat mitigation at renewed mining sites in western Colorado 1. Avoid re -entry into winter roosting sites (hibernacula) during the hibernation season of use. Bats are very vulnerable at this stage, and disturbance and mining activities can be both directly and indirectly deadly to bats roosting in these mines at that time. In western Colorado, where the uranium mines are located, the winter season should be considered from October 1 — April 15. Disturbance at winter roost sites can be greatly reduced by planning initial re -entry work around these dates. Once bats become active again, they can respond and disperse to the activity at the mine, hopefully avoiding any direct impact to individual bats. 2. Prior to re -entry into winter /fall roosting sites, exclusions should be conducted to help prevent the entry and use of the site by bats. This would involve screening out bats by placing chicken wire (1" mesh or more) across the entire bat gate, as well as any un -gated but open access point to the mine complex. The chicken wire should cover the gate from the top to about 5 -6" from the floor or bottom of the gate. This will help prevent bats from entering the mine, and also allow any bats that may be inside the mine prior to the exclusion effort, to escape for the mine before the mining operations begin. I would suggest that exclusions begin by September 1 at these fall/winter sites. They can go up at any time prior to the start of the fall transition season, but no later than September 30, to avoid weather related variations to fall bat activity. In addition, exclusions are not functional from October 1 — April 15, because bats are not active. 3. Summer roosting sites, other than at maternity roost sites, can be handled in the same manner, with bat exclusions. I recommend that mines fitting this profile should have a chicken wire exclusion for at least 2 -3 weeks prior to any re -entry of the mine. Again, the wire should cover the entire bat gate and any other un- gated but open access point to the mine complex. The summer season can be considered April 15 — September 1St. 4. Maternity roosts will be the most critical, as these roosting habitats are very rare. Re -entry and potential loss of these roost types will require more advanced planning. I recommend that any maternity site that cannot be avoided for re- entry, undergo an exclusion effort by April 15. The ideal situation would be to allow the exclusion effort to cover the first half of the maternity season, at least, to prevent any attempt for the colony to try and re- establish use while operations are underway. That would provide an exclusion period of April 15 — June 15 In addition, I would suggest that after re -entry of the mine for mining, that the portal(s) be covered during night time periods, to prevent the potential of re -use at maternity sites. 5. For sites that have bat use year round, the target time periods for renewed mining activity should be spring or fall. This would be an April -May period, or September- October time period. STATE OF COLORADO John W. Hidcenlooper, Govemor • Mike King, Executive Director, Department of Natural Resources Rick D. Cables, Director, Colorado Parks and Wildlife Parks and Wildlife Commission: Robert W. Bray • Chris Castilian • Jeanne Horne Bill Kane, Vice-Chair • Gaspar Perricone • James Pribyl • John Singletary, Chair Mark Smith, Secretary • James Vigil • Dean Wingfield • Michelle Zimmerman Ex Officio Members: Mike King and John Salazar