The 20km dual carriageway site goes through three places where great crested newts have been found.
Balfour has to find them now they are coming out of hibernation under Natural England regulations.
Rocky and his handler Aran Clyne of Wagtails has been brought in to help carry out final checks before the areas are disturbed before construction work.
Sniffer dogs are much quicker that traditional surveys and Rocky can cover areas in minutes which ecologists previously took days to search by hand.
Rocky can show where searches can be concentrated and which areas are clear of Great Crested Newts.
Most newts are caught during 60 days of trapping.
Balfour has erected over 7km of amphibian fencing to steer them into bucket traps that are checked on daily by ecologists from Mott MacDonald, who hold the Natural England mitigation licence.
Anything caught is transferred into suitable habitat outside of the construction site.
So far over 350 great crested newts have been trapped and safely relocated away from the line of the road – plus 450 smooth newts, over 850 toads, 90 frogs and an assortment of reptiles and mammals including a baby hedgehog.
Balfour started on the site in January and work is due to be completed by the end of 2017.
If you are a dog lover visit Howcuteismydog.com to vote on the country’s cutest pets.