Question 18M.2.HL.TZ1.1i

White-nose syndrome (WNS) is a disease caused by the fungus Geomyces destructans. This kills bats from many species during their winter hibernation Scientists used echolocation to record the number of bat flights over a station in 10 minute sample periods during the summers of 2007 to 2009. The graph shows the mean number of flights and number of recording samples for little brown bats (Myotis lucifugus), a species affected by the fungus, along with those of hoary bats (Lasiurus cinereus), which are not affected.

Scientists have hypothesised that bats affected by WNS could be more likely than unaffected bats to emerge from hibernation during the winter. Bats occasionally undergo short interruptions in hibernation accompanied by an increase in body temperature. Scientists used sensors attached to M. lucifugus to monitor the temperature of a group infected with the fungus over the winter months. A second uninfected group was also monitored. The graphs show the results for two typical individuals.

The graph shows data from a small group of infected bats that died during hibernation. The average time interval between hibernation emergence periods and the date of death were recorded using temperature sensors for these bats.