Networks for Nature: How DBRC data is creating more species-friendly highways

The Devon Biodiversity Records Centre (DBRC) will be presenting its work partnering with National Highways and The Wildlife Trusts on the Networks for Nature project. DBRC are using local biological records and land use data to model species dispersal through a landscape, aiding in targeted habitat restoration to improve connectivity (such as culverted underpasses, green bridges and tree planting).

Adam Falconer is a technical officer for Devon Biodiversity Records Centre. He studied Biological Sciences at the University of Exeter and previously worked on revising the Ancient Woodland Inventory for Devon.

Q&A with Adam Falconer

Did you use actual roadkill data in your model?
Yes – roadkill data was used as part of the presence/absence data that we used to build our habitat area. Our road interaction data was fairly accurate, but where we had genuine roadkill data we updated the road interaction data if it didn’t think there was definitely a chance of roadkill there.
What species did you choose for the model?
There’s quite a long list that includes Badgers, Dormice, Harvest Mice, Hedgehogs, Otters, Barn Owls, Goshawks, Tawny Owls, Toads and Great Crested Newts. We also used Deer as a broad category and undertook some speculative modelling for Pine Martens. We tried to include Hobbies but they were very difficult to model. In contrast, the Narrow-headed Ant was relatively simple to model due to a single known population on either side of the A38.
Have the Highways Agency provided any feedback regarding the impact of this project?
This project is still ongoing and we are getting the final few models out. The Highways Agency will be going over our models and the research by ANIMEX, and then providing their feedback on the whole process.
What was involved in the in-person surveys referenced in the presentation?
I actually didn’t get to go on any as I was chained to my desk doing modelling! My understanding is that it involved noting the type of crossing point (e.g. culvert, bridge), dimensions of the crossing point and walking the crossing point if possible (as you can’t go through a small culvert obviously). Surveyors also walked both sides of the road and mapped the available habitat. From all this information, the specialists then came up with a list of suggested improvements that could be made for any species. This was then compared to the model and trimmed down to what species were likely to be in the area.
What types of intervention are Highways Agency considering to assist wildlife crossing roads safely?
Some of the interventions discussed included mammal shelves (these benefit a broad range of species including Otters), removal or widening of grates (to enable access to species that may have been too large and therefore barred from using the crossing point), raised flight lines (particularly relevant for Barn Owls as the nature in which they glide from highest point to highest point puts them at risk with taller vehicles like lorries). This project is focused on improving existing infrastructure, rather than constructing new features (like green bridges) and looking for quick but efficient improvements.
Did you have a cut-off date for the age of the records used?
We tended to use records within the last 10 years. However, if we were aware of records that were not in our database we could actively seek them out. For example, I was aware of a situation where Greater Horseshoe Bats used a culvert from a previous role and added this data as it was not within the LERC datasets.
How long has this project been running and how many staff work on it?
The project has been running for around 6 months and has had 1 staff member working on it throughout for about 2-3 days per week.