Veteran trees and their importance to bats
Veteran trees are impressive natural structures of great age and biological importance and this abstract from an 1876 diary entry by The Reverend Francis Kilvert highlights the age and magnificence of our veteran trees:
“those grey old men of Moccas, those grey, gnarled, low-browed, knock-kneed, bowed, bent, huge, strange, long-armed, deformed, hunchbacked misshapen oak men that stand awaiting and watching century after century biding God’s time with both feet in the grave and yet tiring down and seeing out generation after generation.”
Normally associated with woodland pastures and parkland, veteran trees can also be found along boundary banks, in hedgerows, along river corridors and in woodlands. Over their lifespan, these veteran trees will have supported an impressive range of wildlife from plants, lichen, fungi, to insects, birds, reptiles, amphibians and mammals including our only true flying mammal, the bat.
Brown Long-eared bat
Bats also need shelter known as a roost, to raise their young, hibernate through the winter months and protect themselves from predators and the weather. Natural features in trees (trunk cavities, hollows, rot holes, bark crevices, cracks, fissures, split beams, lifted bark plates, knot holes, basal cavities, split branches and Woodpecker holes), formed by decay, damage and age can provide these roosts, which our woodland bats rely on, and any tree (even young specimens) can support these features. However an older tree will have had more time to develop and showcase these features, and therefore will provide more roost opportunities.
What bats will use however will depend on the species and the seasons. For example, some of our woodland specialist like the rare Bechstein’s bat, and our biggest bat, the Noctule will favour woodpecker holes, while the Barbastelle utilises crevices in split branches and cavities behind lifted, flaky bark plates. In the summer, female bats will be rearing their young and require features high up in a tree that are warm and safe. Meanwhile in the winter, bats like the Barbastelle, Noctule and the Bechstein’s bat will be hibernating so they will need features that go deep inside the tree, where the temperature is cool and stable and they can sleep undisturbed through the cold winter months.
In the UK our bats are small, furry creatures of the night moving through the landscape in search for food, feeding on insects like midges, flies, moths and beetles. We are lucky enough to have 18 species of bats in the UK and trees play an important role in supporting the large variety of insects that they feed on. The older the tree is, particularly if it is a native tree, the greater abundance of insects it will support. This is where those ‘grey old men’ come into their own! As they become a fixture in the landscape, they will provide a variety of microhabitats as well as habitat continuity, therefore supporting a wide range of insects and wildlife.
So when you next come across a ‘grey old man’, take a pause and study its old gnarled, twisted branches. Appreciate its importance to our wildlife (those cracks, holes and crevices are likely to be a home) and wonder at the changes it has experienced over the years.
Bat Conservation Trust
(c) Bat Photos - Hugh Clark, Bat Conservation Trust
Would you like to help these incredible species? There are numerous ways in which you can:
- Why not volunteer for Back from the Brink? Check out our events page for opportunities near you.
- Help us to spread the word of this species, and the others we will be helping over the next 3 years, by sharing our message across our Twitter, Facebook, Instagram and YouTube pages. Follow us: @naturebftb.
- Finally - help support the work we do across England by donating. Our impact will be greater with your help.