Great article, definitely recommend. Excerpt:

A staggering number of variables influence the risks: bird behavior, the nature of the pathogens, the insects and other vectors that help spread them, and humans’ own habits and effects on the landscape. And as the world warms there’s a new variable to consider, says Martin Beer, a veterinarian at the Friedrich Loeffler Institute (FLI) who is Günther’s Ph.D. supervisor. “Bird migration, breeding, and everything is connected to climate change.”

As birds migrate to feed or breed, rising temperatures and changing moisture patterns are likely to affect where they go, how long they stay, and what pathogens they meet. The VEO group is on particularly high alert for birds that travel through Europe to the Arctic, which is warming faster than any other part of Earth and serves as a mixing pot for many species.