The ecologists at Cornwall Environmental Consultants (CEC) Ltd and Cornwall Wildlife Trust are in a race against time to finish up seasonal surveys before many animals hibernate for the winter.
Jenny Stuart, Senior Ecologist at CEC, said: "The main survey season for bats and reptiles finishes at the end of September, though dormice surveys can continue to the end of November.
"Bats, reptiles and dormice all go into hibernation for most of the winter months.
Bats will be moving into their hibernation sites during October and early November, though they will still have periods of activity during the winter – maybe moving between sites if we have a warmer spell, or making the most of the occasional mild night in the winter to feed.
"The Environmental Record Centre for Cornwall and the Isles of Scilly receive many reports of bat sightings from early spring, but it's usually late April/May before they are fully active again.
"Dormice are among the sleepiest of all, going into hibernation in November, and often not emerging until May!
Although there are occasional reports of active dormice in the middle of winter, particularly in the milder South West."
This seasonal change in activity determines the surveys ecologists can undertake at different times of the year. Some surveys for bats and dormice can still continue in the winter – visual inspections of potential roosts can still be made, as tell-tale signs will still be present and, if sites are thought to support hibernating bats, these can be surveyed too.