Mark Foster
Demonstration of bat surveying techniques.
Out in the field: bats and trees habitat workshop at Chatelherault Country Park.
On 5th November the Scottish Branch presented a bats and trees habit workshop at Chatelherault Country Park.
This large park in Hamilton, South Lanarkshire, derives its name from the French town of Châtellerault as the title Duc de Châtellerault was granted to James Hamilton in 1548 for his part in arranging the marriage of Mary, Queen of Scots, to Francis, Dauphin of France. The park has a host of natural and scientific accolades attached to its name and for good reason. As well as having a Bronze Age burial site, it has a plethora of fauna, flora and funga that drew the Scottish Branch’s bats and tree habitat event.
Senior ranger of the park, Mike Brady, opened the morning by giving us a deeper understanding of the habitat opportunities the park offers to a large range of wildlife and specifically to bats. Six species have been recorded at Chatelherault with the Daubenton and pipistrelle contributing the largest numbers. The Daubenton are mostly recorded around the Water of Avon, a tributary of the mighty River Clyde, while pipistrelles are found throughout the park. The south-facing site of the former Cadzow Palace has a horse-shoe-shaped avenue of lime trees with a managed grassland that is teeming with insects, a bats dining heaven. The famous Cadzow oak parkland dates from the mid-12th century and some of the trees may be survivors from the original planting. The niche habitat these trees offer is remarkable: the oaks are the only known site in Scotland for the hairy fungus beetles (Mycetophagus populi). These trees also offer many of the features that would be identifiable as potential habitat for bats. Chatelherault is a wonderful site that’s well worth visiting.
It is worth noting that the delegates at this workshop could be split fairly evenly, coming with either an ecology or an arboricultural background. This contributed to a shared thought process throughout the day, although there are clear differences that are beginning to be rectified within the arboriculture industry, such as the language we might use to describe a particular part of a tree. Where an arborist may see a cavity as a ‘fault’, an ecologist may see it as ‘feature’. An arborist’s work is often solution based, where a ‘fault’ is identified and the arborist will attempt to make a solution, usually with a saw. What if we changed the language we use to describe the problem and looked at the ‘fault’ as a ‘feature’ or even better, a potential roost feature (PRF)?
Our next presenter, Jim Mullholland, fuses ecology and arboriculture together in his approach and understanding. From the outset Jim’s enthusiasm for bats and trees was clear and his ongoing research is providing hard evidence about the relationship between bats and trees. The most reliable guidance document is Bat Roosts in Trees: A Guide to Identification and Assessment for Tree-Care and Ecology Professionals. Jim took us through the 20 PRFs (potential roost features) detailed in this document and provided us with a clear visual guide of these features that he has recorded being used as roosts. Jim gave us a huge amount of information to digest with particular significance for how a far more joined-up approach would be beneficial to everyone involved, especially the bats and trees. I can recommend seeking out some of Jim’s articles in back issues of this magazine, and as his work continues, there are bound to be many more.
The final speaker was Davy Whyte, a local arborist whose practical experience of working with trees and bats is second to none. As a result, Davy has a huge amount of information to share. He spoke about his early-career recognition of the lack of care and attention given to potential bat activity in trees by arborists, acknowledging the problems that come up when vocalising these concerns, especially as a contract climber. Davy suggested that every arborist crew should have a qualified ecologist or licensed bat worker as part of the team, a point that is hard to argue against if the industry is dedicated to providing a thorough, holistic tree care service.
Alongside the presentation, there was a full display of potential PRFs that Davy has removed from trees. All is not lost after they have been removed as they can be reattached to standing trees to provide suitable features for bats. Davy is an advocate of recycling and not chucking features through the chipper. In fact, he offers a cash or whisky incentive if you can save a potential feature for him. Attaching a feature to another tree doesn’t take much time, cost or effort, nor does some creativity with a chainsaw to make a PRF, so give it a go next time you’re up a suitable tree.
Davy and his colleague Hattie provided us with a practical aerial demonstration of the use of an endoscope and gave further information about surveying, attaching features and their own experiences that was very helpful to everyone. All of the group stayed focussed on the demonstration and conversations began that were insightful and thought-provoking to finish the day, topping us all up with some new tree juice.
The Scottish Branch would like thank all the speakers, Chatelherault Country Park and all the delegates who contributed to making this a very successful event.
This article was taken from Issue 200 Spring 2023 of the ARB Magazine, which is available to view free to members by simply logging in to the website and viewing your profile area.