Karen C. Drayer Wildlife Health Center

West Nile Virus

Potential Effects of West Nile Virus on California Wildlife

Press release, June 29, 2004

West Nile virus could pose a serious threat to some species, especially rare and endangered birds, in California. The Wildlife Health Center has produced a report that outlines geographic areas and species at risk.

Please download the report here (pdf, 5.6 MB; a version without images is available here, 136K). A high-resolution map of showing WNV risk in California can be found here (1.5 MB).

To report a dead bird, please call 877-WNV-BIRD (877-968-2473)

There are a number of excellent sites dealing comprehensively with West Nile Virus:

The Wildlife Health Center needs your support to learn more about West Nile Virus in California birds. Please click here to help.

California birds affected by WNV

The following are the bird species that were positive for WNV in California as of mid-August 2004 (Vector-Borne Disease Section California Departmen tof Health Services). A new batch of birds were reported positive on August 19 which included the following new species: Bank Swallow, Black-shouldered Kite, California Quail, Common Nighthawk, Domestic Goose, Evening Grosbeak, Rock Dove, Sharp-shinned Hawk, Song Sparrow, and Western Screech-Owl. The numbers will be updated on Monday, August 23.
Testing has now begun on tree squirrels too (a few from Southern California have tested positive for WNV).
SPECIES (29 total, 7 new)

  • Acorn Woodpecker 1
  • American Coot 1
  • American Crow 1182
  • American Goldfinch 1
  • American Kestrel 2
  • American Robin 2
  • Barn Owl 6
  • Barn Swallow 1
  • Black Phoebe 2
  • Black-headed Gosbeak 1
  • Brewer's Blackbird 3
  • California Gull 1
  • California Towhee 1
  • Common Raven 19
  • Cooper's Hawk 7
  • Great-horned Owl 1
  • House Finch 7
  • House Sparrow 7
  • Mallard Duck 3
  • Mourning Dove 1
  • Northern Goshawk 1
  • Northern Mockingbird 8
  • Red-shouldered Hawk 2
  • Red-tailed Hawk 3
  • Rufous Hummingbird 1
  • Steller's Jay 6
  • Western Tanager 1
  • Western-scrub Jay 110
  • Yellow-billed Magpie 66