13/08/2025
Summary of bats so far this year. Refer to the count photos on earlier posts for more details. This year it hasn’t rained much in the last few months, hence the comments (drought, need gentle rain – for example) from the volunteers who count our Mansion Horseshoe Bats on Sunday evenings.
Here is a summary of the weekly exit count numbers for Greater Horseshoe bats since the post on 14 June.
Date Adults Pups
15/06/2025 113
22/06/2025 122 9
29/06/2025 138 47
06/07/2025 147 74
13/07/2025 - -
20/07/2025 146 ?
27/07/2025 192 ?
03/08/2025 187 9
Unfortunately, the CCTV cameras were malfunctioning on 13 July, so the normal weekly exit data could not be recorded. Instead the whole colony of Greater Horseshoe bats was caught and processed. There were 207, of which 132 would have gone out to forage overnight.
This year 77 Greater Horseshoe pups were born, which is slightly down on our average of 84 over the past 8 years. 2025 births started on 17th June and ended on 10th July. On 27 July, many pups were flying outside to forage, so not relying solely on milk from their mothers. The pups grow quickly to over 95% of their full size over their first 30 days, when they start foraging. It is impossible to distinguish them from their mums. From age 60 days they are fully grown skeletally, but they take 2 or 3 more years to develop their internal organs to full size. This need delays them beginning to reproduce. Males take until their third summer, and females until their 3rd or fourth one normally.
The weekly count data doesn’t tell us how many Lesser Horseshoe pups were born in any year, since their roost is not entered to count them after their exit. The primary study of bats in the Mansion has always been Greater Horseshoe bats.
Many thanks to the team who do the weekly exit counts and Dr. Roger Ransome for comments on my initial draft of this post.
Do come down to the Mansion to see our bats on the live CCTV cameras in our bat observatory (during normal opening times). Standard admission charges apply, though for the school summer holidays we have a special admission rate for 2 adults with up to 4 children.
For details on opening times, see
www.woodchestermansion.org.uk/visiting-us/open-days-minibus/
For admission charges, see
www.woodchestermansion.org.uk/visiting-us/admission-prices/
For lots of good info about bats, see
www.woodchestermansion.org.uk/bats/
