Two young kea have died after suspected car surfing at Deaths Corner in the Otira Gorge.
The Department of Conservation said both birds suffered head injuries from similar incidents in the past week.
Senior ranger Chris Stewart, from DoC's Arthur's Pass team, said the parrots were known for landing on cars and picking things off, but sometimes when the cars took off the birds stayed put.
"When the car gets going, they are really in trouble," Mr Stewart said.
It was not the first time kea had been seen car surfing in the area, however an unusually high number of birds had been congregating at the Otira Viaduct lookout this year, he said.