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Guidelines for bat mitigation at renewed mining sites in western Colorad <br />1. Avoid re -entry into winter roosting sites (hibernacula) during the hibernation seasorn of use. <br />Bats are very vulnerable at this stage, and disturbance and mining activities can be both directly <br />and indirectly deadly to bats roosting in these mines at that time. In western Colorado, where <br />the uranium mines are located, the winter season should be considered from October 1— April <br />15. Disturbance at winter roost sites can be greatly reduced by planning initial re -entry work <br />around these dates. Once bats become active again, they can respond and disperse to the <br />activity at the mine, hopefully avoiding any direct impact to individual bats. <br />2. Prior to re -entry into winter /fall roosting sites, exclusions should be conducted to help prevent <br />the entry and use of the site by bats. This would involve screening out bats by placing chicken <br />wire (1" mesh or more) across the entire bat gate, as well as any un -gated but open access point <br />to the mine complex. The chicken wire should cover the gate from the top to about 5 -6" from <br />the floor or bottom of the gate. This will help prevent bats from entering the mine, and also <br />allow any bats that may be inside the mine prior to the exclusion effort, to escape for the mine <br />before the mining operations begin. I would suggest that exclusions begin by September 1 at <br />these fall /winter sites. They can go up at any time prior to the start of the fall transition season, <br />but no later than September 30, to avoid weather related variations to fall bat activity. In <br />addition, exclusions are not functional from October 1— April 15, because bats are not active. <br />3. Summer roosting sites, other than at maternity roost sites, can be handled in the same manner, <br />with bat exclusions. I recommend that mines fitting this profile should have a chicken wire <br />exclusion for at least 2 -3 weeks prior to any re -entry of the mine, Again, the wire should cover <br />the entire bat gate and any other un -gated but open access point to the mine complex. The <br />summer season can be considered April 15 — September 1 <br />4. Maternity roosts will be the most critical, as these roosting habitats are very rare. Re - entry and <br />potential loss of these roost types will require more advanced planning. I recommend that any <br />maternity site that cannot be avoided for re -entry, undergo an exclusion effort by April 15. The <br />ideal situation would be to allow the exclusion effort to cover the first half of the maternity <br />season, at least, to prevent any attempt for the colony to try and re- establish use while <br />operations are underway. That would provide an exclusion period of April 15 — June 15 In <br />addition, I would suggest that after re -entry of the mine for mining, that the portal(s) be covered <br />during night time periods, to prevent the potential of re -use at maternity sites. <br />5. For sites that have bat use year round, the target time periods for renewed mining activity <br />should be spring or fall. This would be an April -May period, or September - October time period. <br />