Hendricks. The June to mid-.Iul\ extremes in 

 mean temperature (3.6 °C and 12.2 °C) also 

 occurred in the Hendricks Mine. Extreme \alues 

 occurred in this mine because of significant air 

 movement through parts of the workings, while 

 other parts experienced \ er\' little air movement. 

 For all data logger locations, summer mean 

 temperatures were 2.5 ± 2. 1 °C warmer than in 

 \\ inter The same pattern was evident for relative 

 humidit>'; summer means were 1 2. 1 ± 9.2% 

 greater than in winter However, in the Main Drift 

 of tlie Hendricks Mine summer relatix e hiunidit>' 

 was actually a few percent lower tliiui in w inter 

 (Table 2), the only data logger location where this 

 occurred. 



Mean mine temperature tended to decrease with 

 increased ele\ation in both winter and summer 

 (Figure 2), but relative hiutiidit)' did not show a 

 significant elevation trend for either period (winter: 

 r = -0.364, P = 0.376; summer: r = -0.308. P = 

 0.458). For both temperature and relative humid- 

 it\-, summer means were highh' and positively 



correlated w ith w inter means (Figure 3 ). How- 

 ever. \ariation (measured as the standard devia- 

 tion) in temperature and relative humidit)' for the 

 winter and summer periods at each data logger 

 location was only weeikly correlated {r = 0.387, P 

 = 0.191 and r = 0.165, P = 0.591). 



We noted significant airflow in three mines, the 

 Union. Hendricks, and Unnamed Adit # 2. and 

 slight airflow in the shallow location of the 

 McDonald Adit # 1 . In the Union and Hendricks 

 mines, we never saw bats or concentrations of 

 droppings where airflow was greatest (the first 

 level of the Union. Graeter Tunnel and First Drift in 

 the Hendricks), although scattered droppings were 

 present in these portions of the mines (Table 2). 

 Mean temperature difference between winter and 

 summer was larger at locations where there was 

 significant air movement (4.88 ± 1 .26 °C versus 

 1.03 ± 0.70 °C. / = 7.19, df = 11. P < 0.001). 

 Air movement did not have a similar effect on the 

 mean difference in winter and summer relative 

 humidity (/ = 0.79. P = 0.444). 



Table 2. Daily mine temperature (°C) and relative humidity (%) for winter (10 Jan-30 

 Apr) and summer (1 .Iun-13 Jul). Values are means ± 1 standard deviation. Asterisk 

 indicates location is a known bat hibernation site (winter) or a maternity/day roost site 

 (summer). 



