According to a statement from the Smithsonian Conservation Biology Institute, the population of Island Scrub Jays puts it into the top ten rarest US birds. The bird is endemic to Santa Cruz island off the Ventura County coast. From an NBC News report:

The study estimates that there are 2,500 scrub jays living in the wild. The scientists counted jays at more than 300 locations on the island and used a computer model to fill gaps in their data. Using vegetation maps, they found the birds were most prevalent in areas dominated by scrub oak trees.

As a result of this study, the International Union for Conservation of Nature has changed the island scrub jay's status from near-threatened to the higher-risk category of vulnerable, according to the statement. Threats to the bird's small population include restricted island range, lack of genetic diversity, West Nile virus and loss of habitat to oak disease and wildfire.

(Via MSNBC)

(Photo by Devon Pike)