Light levels.

It seems to have been wet for ever. Not the extreme weather of last year. Just continuously wet and damp.

Bat surveys can’t be done in the wet and bats can’t forage. I did one bat survey, arriving on site fifteen minutes before sunset, and there were Common Pipistrelles already feeding amongst the trees at the end of the garden. It had rained for a couple of days before so the bats were hungry. The evening was overcast, so the light level was low. Hungry bats had therefore come out earlier than usual. Braving the possibility of being picked off by birds of prey, in order to get fed!

The books say that Pipistrelles will come out about fifteen to twenty minutes after sunset. But, should we rather being saying that bats will come out at certain light levels?

Bats don’t watch the clock. They don’t read the books about what they are supposed to be doing. They must have some sort of sense about when the light level is right for them to go out, and not be liable to be someone else’s dinner. So, should we be measuring the light levels when the first bats emerge?

A talk with another bat worker who understands technology better than I do led to an idea that you could use the old style light meters used with 35mm cameras, and available second hand. The light levels on the meter should be able to be correlated to light levels measured in Lux from a light meter. This would allow light levels to be measured in a standard unit that could be used any where. Measurements could then be compared between sites and at different times of the year to see if there are any patterns about emergence.

Releasing a bat.

Being on the care and rehabilitation list for the region brings you calls at all sorts of odd times and for places you’ve never been. A month ago I received a call that someone had found a bat on the path outside their office. The office was only just down the road, so I called in and collected the bat. It was a juvenile Common Pipistrelle that appeared quite healthy. No wing damage. No wounds. So probably not cat damaged, which is always a relief when collecting a grounded bat!

Handing it on to someone who is better organised and more skilled at looking after bats is something you have to do when you have four children. The same day I collected another Common Pipistrelle from about a quarter of a mile away, so a busy day!

Last night I took the first bat to release her. The lady who had found her wanted to see her released. She had become fascinated by bats after being told their life cycle and shown the grounded bat when I collected her.

The bat had put on weight and had been to the flight cage to show everyone she could fly. I’d had her for two days, feeding her on meal worms. The evening was overcast but warm. I held the bat in my hand for a few minutes while the lady who had found it and I talked about bats. The bat warmed up nicely and began to get active in my hand, trying to escape. So, it was time to release her. And off she flew, into the distance and off into the dark.

The other bat still isn’t flying but hopefully it will. The big plus though is getting people to be involved in bat conservation. Seeing other people get as enthusiastic as any other batty person and want to support bat conservation in any way they can.