In spring each year I, like most bat-workers champ at the bit, waiting for the survey season to kick off in May. I can't resist looking at some of my favourite roosts, to see if any bats have arrived yet. A couple of weeks ago I spent a fruitless evening watching the roof of our cottage, to see if any of our resident Common Pipistrelles had showed up yet - they hadn't.
Last week Charlotte Meyer-Wilson and I visited one of our favourite Soprano Pipistrelle maternity roosts to see what was happening. In summer around 1,000 bats occupy this roost, but we were happy to see 13, especially as we were playing with an infra-red video camera, which allowed us to see into the roost entrance and watch the bats moving around and interacting, prior to emerging.
It's at this time of year that I watch out for what I think of as the 'harbingers of spring' - three common hedgerow plants that flower early and stand out, each one showing that the bat season is a little closer.
The first to appear is Coltsfoot (Tussilago farfara), its cheerful yellow flowers poking through the flattened mat of last year's dead vegetation. Its chunky, scaley stem is almost a reminder that it's tough and flowers before anything else round here.
My third botanical harbinger of spring is Garlic Mustard (Alliaria petiolata). Following on from the other two, the speed at which their tall stems zoom up in every hedgerow is amazing, allowing them to flower and set seed before they’re overwhelmed by the mass of species that follow.
When garlic mustard shows I know that within 1-2 weeks the hedgerows will, for a brief period, be awash with swaying white Garlic mustard flowers. And that means it's time for the bat survey season to start, which puts an even bigger smile on my face!Keep up to date with the latest posts Facebook.com/Davidsbatblog