Experiment 2
THE EFFCT OF WIND ON WTER EVAPORATION AND THERMOREGULATION
We simulated the effect of wind on water loss and thermoregulation in hamsters by measuring the rate of evaporation and heat loss from a water filled glass vessel wrapped in the fresh pelt of a hamster under both simulated windy and calm conditions. The rate of water evaporation under simulated wind was significantly greater at 32.5°C than at 21°C after 27min (30min, F 1,8=6.03, P<0.05, Figure 6A). The slope of water evaporation was significantly increased by both temperature and exposure to simulated wind (F 1,8=21.98, P<0.01, Figure 6B). Exposure to simulated wind significantly decreased both the rate (3min,F 1,8=5.84, P<0.05, 30min,F 1,8=107.15, P<0.01, Figure 6A), and the slope (F 1,8=239.18, P<0.01, Figure 6B), of water evaporation.
The temperature of water filled glass vessels decreased more slowly at 32.5°C than at 21°C (1min, F 1,8=9.34,P <0.01, 60min, t4=219.28,P <0.01, Figure 6C; slope,F 1,8=46.61, P<0.01, Figure 6D). Cooling was significantly affected by simulated wind; under simulated windy conditions the temperature fell by 47.8% at 21°C and by 25.2% at 32.5°C compared to vessels that were not exposed to simulated wind (1min, F 1,8=8.33, P <0.01, 18min,F 1,8=406.67, P<0.01, Figure 6C). The difference in slope between simulated windy and calm conditions was 88.4% at 21°C and 70.3% at 32.5°C (F 1,8=410.02,P <0.01, Figure 6D).
The cooling of water-filled glass vessels was significantly slower at 32.5°C than at 21°C (5min, F 1,8=5.49,P <0.01, 30min, F 1,8=228.53,P <0.01, Figure 6E) and the difference in the slope of temperature change was 19.98% less at 32.5°C than at 21°C (F 1,8=494.70, P <0.01, Figure 6F). Wind significantly increased the rate of heat loss at both 21°C and 32.5°C (5min, F 1,8=6.74, P <0.01, 30min, F 1,8=56.50, P <0.01, Figure 6E), and also significantly increased the rate of temperature change (F 1,8=112.14, P <0.01, Figure 6F).