Yosemite Transect Survey

2005 Report

This report is divided into three sections, one each for the three terrestrial vertebrate groups that were the focus on the resurveys of the original 22 "Grinnell" sites within Yosemite National Park, as well as outside the park within the transect: mammals, reptiles and amphibians. From April until October we visited 5 of the original sites which included revisits to Crane Flat and Lyell Canyon, plus three additional sites within Yosemite National Park. The herpetological surveys were somewhat more broad, collecting opportunistically in general areas. Like last year, most trips lasted approximately 10 days at each site. Our goals this year were the same as last: (1) to determine faunal changes that have occurred at specific sites in the 80+ years since the original surveys were completed; (2) to document as best as possible the current status of certain rare species; and (3), for some groups, to develop an understanding of the historical uniqueness of target species or lineages present in Yosemite National Park and along the transect in comparison to other regions within the ranges of those species. The latter goal is based on DNA sequence data gathered from sampled specimens obtained during the present surveys and from skins preserved during the original Grinnell surveys and maintained within the collections of the Museum of Vertebrate Zoology. The large scale phylogeography work has not uncovered any new major discoveries, but we are working on intraspecific variation in chipmunks. This, we hope, will shed light on demographic processes in shrinking populations of some species.

Read more about each taxonomic group's resurvey work, PDF files available below.