More Bat Bothering

More bat bothering, or 'bat box checks' which, as described last week, involves walking around a wood with a ladder, then using said ladder to peer into bat boxes where bats will (hopefully) be in there sleeping. In some cases, a bat is hauled out for further examination. This, I should add,  is done by a trained and experienced bat ecologist and the bat, though probably quite annoyed, is unharmed by the experience.

The bat pictured above is a Soprano Pipistrelle, which is Britain's commonest bat and so, as you'd expect, appears the most often in our checks. We also saw a Barbastelle, which is most definitely not Britain's commonest bat and therefore is quite a good bat spot. Sadly no pic of that, as they're quite nervous and probably wouldn't have appreciated being taken out and poked around.

The woods themselves are Holt Wood, which are National Trust owned by the Kingston Lacy estate. On a freezing cold day back in 2013, when I was working as a gardener on the estate, we went for a tour of the woods with Laura Baker, who was then the ranger for this site. She explained their policy of 'haloing', which meant cutting back the understory of the woods, which was mostly holly. Holly, as I'm sure you're aware, is a very thick evergreen plant, which blocks out a lot of sunlight from getting to the forest floor. As well as this, when it's left unchecked and has grown quite high, blocks out light to the trunks of the canopy trees.

These trees, which are mostly oak and beech, start their lives by growing high, reaching their full height fairly quickly (for a tree at least) and then spreading outwards as it matures. However, if the lower parts of the tree is shaded out by holly, then the tree will remain tall and spindly. By cutting back this holly surrounding the bigger trees - or 'haloing' - light will get to trunk and the trunk will start producing little branches with leaves. This is called 'epicormic growth'. In time, these little branches will develop into big branches and the tree will mature into the squatter, fatter trunked shape of a veteran tree. This makes it less top heavy and therefore less vulnerable to high winds and the like.

Well that was the theory, as explained by Laura three years ago. And now, on this visit, you couldn't move for epicormic growth.

Here's a good example, above. This is all very new growth that, before the haloing, would have been completely shaded out by holly. Hanging from the left hand branch is the bat box that we were there to check. Ironically, the bats seem not to like these recently cleared areas, preferring a bit more clutter! But that's the whole thing about ecology, you improve something for one species but mess it up for another.

Not that the bats are too worried. The woods do not lack crevices for bats to hide in. In fact, given the choice you'd be a bit mental to choose a bat box, seeing as their's a fair chance some bunch of herberts are going to come along every month and disturb their day's kip.