Robins tend to fly low over the road, and they have the bad habit of flying directly in front of approaching cars as they fly from one side of the road to the opposite side. I haven't noticed any other birds that consistently do this. I've almost hit a number of robins this year. And when I did hit one several years ago, I felt very badly about it, because they're beautiful, big birds. Maybe if they were just a bit smaller, they'd miss that fender.
Good observation about Robins; they are the worst offenders of flying into fenders.