As in December I left one of the Group’s Anabat Express detectors out in my South Derbyshire garden throughout January. Again the weather was mild, with temperatures at sunset not dropping below 2 °C and averaging 7.4 °C. Wind was not a factor, never above Beaufort force 2 and there was rain at sunset on only one evening.
There are some marked differences compared to the December results. Overall activity levels were down, with bats being recorded on 13 nights and a total of 67 bat passes. Most striking is that only a single Myotis pass was recorded, on 3rd January, whilst this species group was recorded on 18 nights during December. It seems that either they have gone firmly into hibernation and are not being tempted out even on mild evenings, or the local residents have moved to a hibernation roost further afield.
Pipistrelles on the other hand were recorded on 12 nights in January, more frequently than the 9 nights they were detected in December. Temperatures above 8 °C at sunset usually resulted in some pipistrelle activity while they were recorded on only two nights when the sunset temperature was below this threshold. Some social calls were again noted on the 8th and 22nd of the month.
Results are shown in the charts above and the detector is still out so I will update this with the February results when they are all in.
Derbyshire Bat Group Recorder