The researchers tallied vehicles in five U.K. cities and found red vehicles most marked with bird droppings -- 18% of them -- the report said.
The color birds with least appeal for birds: green, at 1%.
The birds' greatest hits by color:
• Red: 18%
• Blue: 14%
• Black: 11%
• White: 7%
• Grey/Silver: 3%
• Green: 1%
The analysis of more than 1,100 vehicles in Brighton, Glasgow, Leeds, Manchester and Bristol, commissioned by car accessory chain Halfords, offered no scientific reason why birds see red when they see a red car.