An evaluation of the distribution and abundance of Common Ravens at Joshua Tree National Park
We located and evaluated data from the past 100 years to assess the historical and contemporary abundance and distribution of Common Ravens (Corvus corax) at and near Joshua Tree National Park in southern California. We found evidence to support the hypothesis that numbers and distribution of this species have increased in the park in the last 50 years. Increases in raven numbers pose a potential threat to populations of Desert Tortoise (Gopherus agassizii), as juvenile tortoises are known prey of the Common Raven. We obtained additional data that support the hypotheses that raven densities may be higher in the Mojave Desert than the Colorado Desert, and that densities appear to be lower in regions with few roads. Some of the largest concentration areas for ravens are found at landfills in the Mojave Desert.
Boarman, William I. and Coe, Sharon J.
"An evaluation of the distribution and abundance of Common Ravens at Joshua Tree National Park,"
Bulletin of the Southern California Academy of Sciences:
Available at: http://scholar.oxy.edu/scas/vol101/iss2/2