Bats

The Bat Group is a small group of enthusiasts founded by Oliver Frazer in 1982 after the 1981 Wildlife and Countryside Act, which gave special protection to bats, became law. We concentrate on projects such as Bat Surveys of Carisbrooke Castle and Quarr Abbey, National Bat Counts in the middle of summer each year and the new Bats and Mammals Road Survey organised by the Bat Conservation Trust.

It has always been difficult to distinguish species of flying bat by sight alone in conditions of poor visibility. Our tools therefore include our own rather expensive hand-held detectors. These convert the bats' high-frequency ultrasonic calls into lower frequencies audible through a speaker. This allows people to identify many species - just like when hearing birdsong.
One can recognise Social Calls as the animals gossip to each other in the roost or fly in a swarm outside; rhythmic Echo-Location sounds given out in time with the exhalation effort of their wingbeats as they navigate and hunt; and rapid sound emissions used to home in on prey such as moths or midges. (The latter gives a high degree of accuracy in focussing on the target, a principal which is "copied" in military aircraft's radar and missiles).
Some of our more sophisticated detectors slow down bat sounds for better distinction in the field. Recordings are made of these for later computer analysis of their waveforms, hopefully giving precise species identification - this is what we are learning to do in the pictures on the Home and Membership Pages.
We are affiliated to the Bat Conservation Trust and that training was part of the preparation for their exciting high-tech Bats and Mammals Road Survey started in 2005. We drove at 15mph around country lanes on several evenings throughout the summer with loaned moving-map GPS Pocket PCs, a minidisc recorder and the above detectors installed in our cars - plus a flashing orange beacon on the roof! This equipment linked together produced masses of data which was sent away for professional analysis and we were given some of it back to fathom out ourselves - for our own education and so we can help with the task in the future.
The same summer bat consultant Ian Davidson-Watts used a laptop computer generating ultrasonic distress calls to lure Bechstein's and Barbastelle bats into mist-nets at Briddlesford Copse, as well as an infra-red video camera to film two dozen Bechstein's emerging from a tree roost at Chillingwood, and we have used night-vision binoculars at Quarr.
In contrast, the Mammals part of the survey simply involved looking out for any wildlife seen on the road, dead or alive, and writing the details down - and even with all the above, examining bat droppings below roost sites remains a regular aid to identification!
Most members of the group have, or are becoming, trained to become licensed by English Nature to handle bats and two of our group, at their own expense, in their spare time, in their own home, involving their family and using their own vehicle as an ambulance, founded the IW Bat Hospital, which now has one of the highest recovery and return-to-the-wild rates in the country.