It seems to me that dead swans are now our harbinger of H5N1 transport.

They have been found in: Turkey, Iran, Azerbaijan, Greece, Italy, Slovenia, and Austria. Probably in more countries also. These I just listed are the countries affected in just the last two weeks that I can recall without doing more research.

How is it that swans can get around with the H5 virus? Do they possibly have a more robust immune system that lets them range afar before succumbing to the disease?

Or, is it a possibility that they are picking up the virus from an asymptomatic vector after arrival at their destination of demise?