Can migrating birds carry rust spores to the United States?
No research has been done on this question; however, the viability of spores that may travel in this way is questionable. Environmental conditions required to keep the spores viable may be compromised. Temperature, high moisture, UV light conditions, oil on the birds feathers, and duration of the trip would greatly impact spore survival. Also, the birds would have to leave South America at a time of the year when Asian rust spores are present.
