[William Wallace]

I am not trying to defend Castro but why would he infect migratory birds to infect the US, when those birds are going to then fly back to Cuba & infect them?

The infected birds don't live long enough to make the return trip.

[Terriergal]

The infected birds don't live long enough to make the return trip.

I don't think you're thinking about this correctly... if they are infected, they will pass the disease (through mosquitoes) along until the next bunch is ready to fly south.

[Ditter]

The first infected birds die, yes, but once the mosquitoes here are infected they infect the birds who fly back to Cuba. The idea that they fly back in the winter & the mosquitoes here are dormant is not correct. In the South US there is never a time that the mosquitoes are dormant.

Only in dry weather, when they have no breeding place, are mosquitoes not prevelant in the south, then & when the temperature is 40 or below. I had one of the worst infestations of mosquitoes last Jan & Feb here in Houston that I can remember. Thats when I bought a Mosquito Magnet.

Once the cycle is started Cuba *will* be infected.