The mosquitoes become infected, and you can create a reservoir of West Nile virus in that local region, ... That's why it makes absolute sense to target that area, even if the bird came from a far northerly section, as it probably did.
Quotes about northerly (3 Quotes)
There is concern there that if that fire does move in a southerly direction under increasingly northerly winds, we do hold concerns for that fire.
The Jet Stream, which typically brings cold air down from Canada into the U.S. in the winter months, has for the last six weeks stayed much more northerly than usual. As a result, our weather has been dictated by a warmer air mass coming across the U.S. from the Pacific Ocean.