What is impact of invasive species on California quail?

Invasive Species Prevalence

The California quail is a native species to the western United States and Mexico, but the presence of invasive species such as feral pigs, sheep, and goats has altered the quail’s habitat. For example, in the San Jacinto Mountains, feral pigs have been known to dig up quail nests, causing the eggs to be destroyed or the chicks to be devoured. The San Jacinto Mountains also have a significant population of non-native grasses, which can lead to overgrazing and reduce the quail’s food sources.

Habitat Loss and Fragmentation

Invasive species can also lead to habitat loss and fragmentation, which can make it difficult for California quail to find suitable breeding and nesting grounds. For example, the expansion of non-native grasses and shrubs in the Sierra Nevada foothills has reduced the availability of dense vegetation, which is essential for quail nesting and foraging. According to a study by the University of California, Berkeley, the expansion of non-native vegetation in the Sierra Nevada foothills has reduced the quail population by 40% in the past 20 years.

Disease Transmission

Invasive species can also increase the risk of disease transmission to California quail. For example, the presence of feral pigs in the San Jacinto Mountains has increased the risk of disease transmission from pigs to quail, such as the avian cholera bacterium. This bacterium can cause severe illness and death in quail, and its presence has been linked to population declines in the San Jacinto Mountains.