Historical and contemporary distributions of carnivores in forests of the Sierra Nevada, California, USA

• Published in: Journal of Biogeography
• Main Authors: Zielinski, William J., Truex, Richard L., Schlexer, Fredrick V., Campbell, Lori A., Carroll, Carlos
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2005
• Subjects: American marten; Gulo gulo
• Online Access: http://dx.doi.org/10.1111/j.1365-2699.2005.01234.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2699.2005.01234.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2699.2005.01234.x

Abstract Aim Mammalian carnivores are considered particularly sensitive indicators of environmental change. Information on the distribution of carnivores from the early 1900s provides a unique opportunity to evaluate changes in their distributions over a 75‐year period during which the influence of human uses of forest resources in California greatly increased. We present information on the distributions of forest carnivores in the context of two of the most significant changes in the Sierra Nevada during this period: the expansion of human settlement and the reduction in mature forests by timber harvest. Methods We compare the historical and contemporary distributions of 10 taxa of mesocarnivores in the conifer forests of the Sierra Nevada and southern Cascade Range by contrasting the distribution of museum and fur harvest records from the early 1900s with the distribution of detections from baited track‐plate and camera surveys conducted from 1996 to 2002. A total of 344 sample units (6 track plates and 1 camera each) were distributed systematically across c. 3,000,000 ha area over a 7‐year period. Results Two species, the wolverine ( Gulo gulo ) and the red fox ( Vulpes vulpes ), present in the historical record for our survey area, were not detected during the contemporary surveys. The distributions of 3 species (fisher [ Martes pennanti ], American marten [ M . americana ], and Virginia opossum [ Didelphis virginiana ]) have substantially changed since the early 1900s. The distributions of fishers and martens, mature‐forest specialists, appeared to have decreased in the northern Sierra Nevada and southern Cascade region. A reputed gap in the current distribution of fishers was confirmed. We report for the first time evidence that the distribution of martens has become fragmented in the southern Cascades and northern Sierra Nevada. The opossum, an introduced marsupial, expanded its distribution in the Sierra Nevada significantly since it was introduced to the south‐central coast region of California in the ...