a ruffed grouse in the snow with its feathers spread out

West Nile virus is still here, and it has killed millions of U.S. birds

The virus, also deadly to humans and intensified by climate change, continues to spread among birds.

A male ruffed grouse struts its stuff in a courtship display seen in Fairbanks, Alaska. Scientists say the species is declining fast because of a combination of West Nile virus, climate change, and loss of habitat.

Photograph by DESIGN PICS INC, Nat Geo Image Collection

Read This Next

Game birds are surprisingly beautiful—and endangered
Is malaria making a comeback in the U.S.?
You really are a mosquito magnet. Here’s what you can do.

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet