Sunday, 25 January 2009

Bat-workers & golf carts: be very afraid!

At this time of year there seems little for a bat-worker to do. Hibernaculum surveys are strictly limited, to avoid the risk of disturbance and there are only so many site visits one can do before running out of enthusiasm for assessing bat potential! These are the days when the mind wanders back to highlights of "real" bat work, before the onset of winter.

One such highlight last year was an autumn visit to a well-known golf and country club in the Borders to check and clean the bat boxes. A large group of bat-workers from Lothians and Borders Bat Groups assembled to go round the boxes, checking them for bats and recording the amount of droppings (an indication of how well each box has been used during the year).

I'm not entirely sure whether it shows trust or naivete, but we were allowed the use of a small fleet of golf carts in order to get round the course with our ladders. If you have never seen a conga line of golf carts, full of bat workers and equipment snaking across the landscape you have never known fear!

Fortunately we were accompanied by the course green keeper and one of his team, which probably helped curb the temptation to descend to the level of "Wacky Races". More importantly, it allowed them to see for themselves the great work they have done, making and erecting bat boxes around the course.

Annual bat box checks have several practical purposes. Firstly, the boxes can be cleaned out in readiness for the next year and any damage identified for fixing. Secondly, we have the opportunity to assess the extent to which each box has been used, providing data which shows the progress of the individual bat box scheme and, when combined with other schemes, a rough measure of how bat populations are doing locally. Thirdly and perhaps most importantly, less experienced bat group members get an opportunity to get close to live bats. Many very active bat workers (including me) started off with bats, with the thrill of seeing a Pipistrelle in a bat box.

In South East Scotland it is extremely rare to find anything other than Pipistrelles in bat boxes (with some intriguing exceptions in recent months) and this site was true to that experience. In autumn boxes tend to be used by male Pipistrelles as the base for a mating territory and it is usual to find boxes occupied by either an individual male or by a male and a harem of females. Where boxes are grouped together it is unusual to find more than one occupied, as they would lie within the same territory. The droppings however, often reveal that other boxes have been used, either earlier in the year or in differing conditions, with bats moving between boxes to find optimum temperate conditions.

The course is home to some remarkable buildings and is known to be home to roosts of Brown long-eared Bats (Plecotus auritus), Common Pipistrelles (Pipistrellus pipistrellus) and Soprano Pipistrelles (Pipistrellus pygmaeus). Best of all is a large maternity colony of Daubenton's Bats Myotis daubentonii). Although the roost was breaking up at the time of our visit, we were still able to glimpse a group of around 20 bats clustered together. I took the photograph below earlier in the year, when there were over 50 bats present, with a cluster of Nycteribia kolenatii bat-fly pupae clustered around (you can see them better in the lower picture).

It was a very successful day in terms of finding bats, recording useful data and giving people the chance to get close to bats. Best of all it was that very rare thing: a chance for bat-workers to get together in daylight!

Please note: handling or disturbing bats is a criminal offence without an appropriate licence issued by a statutory nature conservation organisation (Scottish Natural Heritage, Natural England, Countryside Council for Wales, Northern Ireland Environment Agency).

Most bat groups welcome new members and give them the opportunity to take part in events like this. To find your local bat group contact the Bat Conservation Trust

My website: David Dodds Ecology

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