The Department of Conservation says the "preventable" deaths happened at popular waypoints on the Milford Road (State Highway 94).
Doc senior ranger biodiversity Lydia McLean said tests showed the otherwise healthy kea were killed by blunt force trauma when hit by vehicles.
The deaths could have been avoided by following simple rules, chiefly not offering kea food.
“Kea are incredibly charismatic and naturally inquisitive parrots which is why people love seeing them on their journeys so much.
"However, deliberately enticing them closer by offering them food or other lures is having devastating consequences.
“Not only is human food bad for them but feeding disrupts their natural foraging and draws them towards the road where they are at risk of being run over.
"Sadly, that is what occurred here.”
The kea run over were four juveniles at Monkey Creek, including two which were hit together, and an adult male at the Homer Tunnel in an incident witnessed by a Doc staff member.
Ms McLean while it was difficult to stop the inquisitive birds from interacting with vehicles, there were steps motorists could take to reduce the risk of hitting them.
“Slow down around kea. Take care as you pull away from stopping areas; they don’t move out of the way as fast as you would think, and never drive away if a kea is on your vehicle.
“Remind others that feeding kea is harmful both for their health and because it encourages more scavenging behaviour and leads to more kea on the road and in harm’s way.”
Doc and the Kea Conservation Trust had installed signs at known hot spots discouraging feeding but the message "still doesn’t seem to be getting through".
