Whatever Happened to West Nile Fever?

I found this dead crow in the hedge this weekend, which reminded me of West Nile Fever which, for a time, devastated the crow population on the East Coast. Whatever happened to West Nile Fever?

The bottom line is that the mosquito-borne illness is still out there 18 years later, and it still kills millions of birds a year, and not all of them crows. Warbling vireos (Vireo gilvus), Swainson’s thrush (Catharus ustulatus), purple finches (Carpodacus purpureus), tufted titmouses (Baeolophus bicolor), and wrentits (Chamaea fasciata) have been decimated. People too are not entirely immune. A woman died from West Nile in South Carolina last week and it (apparently) can turn up in chickens as well as wild birds.

The good news is that the infection is mostly asymptomatic and most infected people and birds recover without even knowing they had it.  The crow population, which was particularly hard-hit 15 years ago (nearly 100 percent mortality), seems to have slowly developed a partial immunity as more resistant-birds have survived and propagated. Darwin lives!

What about this particular crow?  There is no telling what got him. It could be West Nile (probably), a respiratory infection, internal parasites, mites, old age, battery from the previous night's storm, or a run in with the red-tail hawk that I could hear keening in the background.  Life is often fairly short for birds, which is why they are such phenomenal reproducers.