Woodchester Mansion is home to two colonies of rare bats.
There are roosts of both Greater (GH) and Lesser Horseshoe (LH) bats, both listed as endangered species, which are known to have been at the Mansion since at least the early 1950s. These bats use the Mansion as a ‘maternity ward’ - arriving during April and May to have their babies (pups) during June and July. Most of them leave in September to spend the winter hibernating. They mainly hibernate in disused stone mines within 25 miles of the Mansion.
The Mansion’s GH bats have been studied by Dr Roger Ransome and his many voluntary helpers, since 1959. It is the longest continuous study of any mammal by a single person in the world. Roger’s studies, and the books and papers he has published from them, depend largely upon records from the Woodchester Mansion colony. Roger has attended most of the international bat research conferences since 1971, and given many talks about his studies. Since each one is normally held in a different country, Woodchester Mansion is globally known as an important bat study site that has provided many new discoveries about bat natural history. In 2000, thanks to the generosity of the Peoples Trust for Endangered Species (PTES), the GH bat attic was fitted with a night-vision camera that uses infrared light to allow public viewing. This was the first opportunity anywhere in the UK, and possibly further afield, for non-scientists to be able to watch wild bat behavior live via CCTV. Two years later, PTES donated a second system for the LH bat attic. One consequence of these facilities is that the myth that bats are either asleep, or torpid, during the daytime is well and truly refuted - visitors are amazed to see just how active the bats are during the daytime - but this is not surprising when we realise that many of the bats in the colonies have babies to look after and as most of us know, babies of whatever mammal are high maintenance!
More recently, Roger and his grandson Michael Abbott, have produced video clips which describe the Bat Exhibition Room at the Mansion and show aspects of the behaviour of some mothers with respect to their young. The video clips are expected to be important during open days at the start of the open day season in late April, and its end in October, when fewer bats are present in the roosts. To support the presentation of these video clips, Roger kindly donated a TV monitor and DVD player to the Mansion Trust. You can see a video clip about the behaviour of the GH bats on the Woodchester Mansion Bats:
Facebook page www.facebook.com/woodchesterbats
Or YouTube account http://www.youtube.com/user/WoodchesterBats
The numbers of GH bats present in the roost in 2011 are higher than at any time since the mid 1960s, with 181 adult Greater Horseshoe bats and 91 babies being recorded on 3rd July. The colony has benefitted from global warming and the habitat improvements being made in the Woodchester Park valley, with help from the National Trust and Natural England. Similarly, LH bat numbers have risen from very low levels in the 1960’s to about 550 adults and probably at least 200 babies. Altogether, over 1,000 horseshoe bats were present in the Mansion in July 2011. Besides these impressive colonies, much smaller numbers of three kinds of vesper bats (non-horseshoes) also roost in other parts of the Mansion. With at least another 7 types of bats that have been recorded feeding near the Mansion after dusk, the valley supports at least 12 and probably 14 of the UK’s total of 17 bats.