In regards to US birds.... this is the article I saw recently:

http://news.nationalgeographic.com/n...united-states/

There was also a more recent one in Science News, that said the marsh birds are not being affected so much as the little song birds.

And about that thiamine.... in Florida, runoff of fertilizers is implicated in loss of alligators in small ponds, due to the fish dying off leaving a species that contains an enzyme that inactivates thiamine...Hence the gators are dying off now too.
http://fl.biology.usgs.gov/posters/E...lligators.html

So I guess there are many factors impacting our environments and thus affected the wildlife.

Thanks for that article John, as it was very interesting.