On a completely different note about ducks vs. robins (pretending the above flame war didn't happen): I can't say whether average folks would make this connection, but it seems to me that robins sit in trees and don't walk around on the ground very often, whereas ducks tend to hang out on the ground (or in the water). Since robin droppings (a typical disease vector) would work their way to the ground, whereas duck droppings would just stay there, it seems like robins would be more likely infect ducks. Again, I don't KNOW this to be the case, but that's not... (read more)
On a completely different note about ducks vs. robins (pretending the above flame war didn't happen): I can't say whether average folks would make this connection, but it seems to me that robins sit in trees and don't walk around on the ground very often, whereas ducks tend to hang out on the ground (or in the water). Since robin droppings (a typical disease vector) would work their way to the ground, whereas duck droppings would just stay there, it seems like robins would be more likely infect ducks. Again, I don't KNOW this to be the case, but that's not... (read more)