They will be the first of their kind for Scotland when they are finished – and they will create a safe walkway for the north-east’s four-legged creatures.
Wildlife bridges and mammal underpasses are currently under construction on the Aberdeen Western Peripheral Route/Balmedie-Tipperty (AWPR/B-T) project to ensure animals can traverse the road without danger once it has been opened to traffic next year.
Badgers, deer and squirrels will be “funnelled” through the crossings which replicate their own habitats.
The two dedicated ‘ecoducts’ are being constructed over the new road at Kingcausie and Kirkhill, where there are large surrounding areas of woodland habitat.
In addition, another bridge across the AWPR at Kirkhill, which will be used by vehicles to access local forests and remote properties, will have one half of its carriageway landscaped for wildlife and equestrian use.
Mammal-proof fencing will guide animals towards the bridges, providing them with safe crossing points which will join up habitats and connect colonies.
Small trees and shrubs will also be planted on and around the bridges to provide cover for wildlife.
The bridges are still under construction, by Aberdeen Roads Limited, and will not be accessible to pedestrians.
A Transport Scotland spokesman said: “These will be the first of their kind on a Scottish trunk road.
“The wildlife bridges, along with 17 mammal underpasses, have specially-designed planting and strategic seeding to encourage biodiversity.
“These are just some of the measures that are considered necessary to ensure wildlife continues to thrive in the area once the road has been built.
“These ‘green’ bridges were successfully pioneered in the Netherlands in 1988, where they are known as ecoducts. There are also now a small number of these structures on some major routes in England.”
“There will be no pedestrian access on either bridge; to have people on the bridges would defeat the purpose of creating a safe wildlife habitat in the first place.”
The mammal underpasses are at various locations across the scheme, including two at Kirkhill Forest.
Scottish SPCA Chief Superintendent Mike Flynn said: “We’re delighted at the decision for mammal underpasses and wildlife bridges to be introduced to help protect Scotland’s wildlife.”
The AWPR/Balmedie to Tipperty route is expected to open next spring.