West Nile Virus Update

Since 2000, the rapid spread of West Nile Virus (WNV) in North America has killed hundreds of millions of birds and more than 1,000 humans. House wrens, bluejays, crows, robins, bluebirds, and titmice have been the most vulnerable.

To date, research has failed to show why species vary in their response to west nile. It is known, however, that mosquitoes feed preferentially on some bird species. These birds then become vectors for amplifying the presence of the virus.

For humans, living next to vegetation within a city increases the risk of infection. In particular, the carrier mosquito, Culex pipiens, is known to shift its feeding to humans when robins disperse from urban areas in late summer.

A review of the current understanding of WNV can be found here.