Skip to Main Content
Turning population trend monitoring into active conservation: Can we save the Cascades Frog (Rana cascadae) in the Lassen region of California?Author(s): Gary M. Fellers; Karen L. Pope; Jonathan E. Stead; Michelle S. Koo; Hartwell H. Welsh
Source: Herpetological Conservation and Biology 3(1):28-39
Publication Series: Miscellaneous Publication
PDF: View PDF (380 KB)
DescriptionMonitoring the distribution, population size, and trends of declining species is necessary to evaluate their vulnerability to extinction. It is the responsibility of scientists to alert management professionals of the need for preemptive action if a species approaches imminent, regional extirpation. This is the case with Rana cascadae (Cascades Frog) populations near Lassen Peak. From 1993 to 2007, we conducted 1,873 amphibian surveys at 856 sites within Lassen Volcanic National Park and Lassen National Forest, California, USA. These surveys encompassed all R. cascadae habitats: ponds, lakes, meadows, and streams on those lands. We found frogs at only six sites during 14 years of surveys, and obtained one report of a single frog at one additional locality. These sites represented < 1% of the historically suitable habitat within the Lassen region. The number of R. cascadae in the Lassen area has declined since 1991, and one population is now extirpated. We found no evidence of reproduction in most of the populations, and reproduction at all but one of the other sites remained lower than the annual reproductive output of one breeding pair for > 12 years. Causes for the decline remain unclear, but introduced trout, disease, and pesticides are likely factors. We recommend that (1) additional protection for R. cascadae within 50 km of Lassen Peak; (2) investigation of the genetics of R. cascadae in California; (3) research into the role of possible causative factors in these declines; and (4) implementation of a feasibility study to captive breed and reintroduce R. cascadae in the Lassen area.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationGary M. Fellers; Karen L. Pope; Jonathan E. Stead; Michelle S. Koo; and Hartwell H. Welsh, Jr. 2007. Turning population trend monitoring into active conservation: Can we save the Cascades Frog (Rana cascadae) in the Lassen region of California?. Herpetological Conservation and Biology 3(1):28-39
Keywordsamphibian, Cascades Frog, conservation, declining amphibian, Lassen, population status, Rana cascadae
- Cascades frog conservation assessment
- Indirect effects of introduced trout on Cascades frogs (Rana cascadae) via shared aquatic prey
- Itraconazole treatment reduces Batrachochytrium dendrobatidis prevalence and increases overwinter field survival in juvenile Cascades frogs
XML: View XML