Amphibian, reptile, bird and mammal populations that depend on freshwater marsh, streamside habitat and wet meadows are struggling because of the drought, according to an assessment released Thursday by the California Department of Fish and Wildlife.

Biologists ranked the vulnerability of the state’s terrestrial species and gave top priority for additional monitoring and assistance to 48 species. The greatest concentrations of these high-risk populations are found in Southern California coastal, mountain and valley regions, the Sierra Nevada, Mojave Desert, Central Valley and the southern Cascade mountain range.

Researchers analyzed and assessed the vulnerability of more than 358 land species. Scientists then classified them into Priority I (most vulnerable) and Priority II (less vulnerable) categories. All of the species evaluated were threatened, endangered or were otherwise considered species of special concern before the drought impacted them.

In the Sierra Nevada and Northern California mountain ranges, amphibians such as yellow-legged frogs, Yosemite toads and Cascades frogs are struggling. Some species’ tadpoles require multiple years to develop into juveniles and lack of suitable habitat has eliminated several years of breeding effort at once. Removal of non-native predatory fish from select areas as well as assistance with disease intervention, translocations and reintroductions are underway to improve their chances of long-term survival.