Yosemite National Park has rich species diversity and many acres of unsurveyed land. Mammalian and other species research in the park appears to be currently limited and does not incorporate the use of modern-day mapping tools and software, such as ArcGIS. I attempted to compile as much information as I could on mammal species occurrences and distributions in the park in order to create maps displaying the results of previous research. Unfortunately, publicly available information on species distributions within the park is currently limited, and geographic information systems data were not available from all sources. I was able to map results of a Grinnell resurvey project completed by the University of California, Berkeley, special-status species occurrences from the California Department of Fish and Game, and general distribution ranges for mammals from NatureServe. Other research provided additional information on mammals in Yosemite National Park. The results of my research indicate that, with additional time and funding, a database of mammal observations, occurrences, and distributions could be created to provide management direction for park staff. This type of tool would be very beneficial to future management of the park’s resources.

Yosemite National Park (Yosemite NP or park) encompasses more than 740,000 acres of diverse vegetation communities, with almost 95 percent designated as wilderness (Yosemite National Park website, available at http://www.nps.gov/Yose/index.htm). In this vast expanse of pristine habitat, more than 400 species of vertebrate animals find their homes, including 90 species of mammals. Many of these animals are considered special-status species, which means they have declining populations, specific habitat requirements, or limited distribution ranges. Others are more common and may be found throughout the park.

Many studies have been conducted throughout Yosemite NP to identify species distributions and presence/absence in support of various research projects and environmental review and permitting processes. These studies provide focused information on species observations in a defined study area; however, they have not covered the entire 740,000-plus acres of the park, much of which is remote and difficult to access. The results of all studies in the park have also not been combined to map the regional distribution of species in the park, including distribution trends or habitat preferences, or to identify survey gaps where additional areas should be surveyed. The lack of funding or technical capability may be limiting factors preventing park staff or others from combining the results of all study efforts. With this knowledge, park staff would have important information on special-status species distributions for management purposes. It is also possible that larger populations of species and greater species diversity and richness occur in the park than what is currently known.

The purpose of this research project is to compile available data on occurrences of mammal species, including special-status mammals, in Yosemite NP and determine the approximate distribution of the species in the park. The research component of this project involved searches of federal, state, and local government websites as well as websites for universities, non-profit research groups, and other sources to obtain publicly accessible studies and survey results, including geographic information systems (GIS) data covering the park. Publicly available GIS data are limited, however, and research and survey results are difficult to obtain without direct contact with the authors or organization they work for. Some research is also out-dated and did not incorporate use of modern-day technology, such as GIS data or geographic positioning systems (GPS). The research results are displayed in this report in text and graphic format using ArcGIS 9.3 to provide visual representations of the geographic locations of occurrences and present the estimated distribution of some mammals in Yosemite NP based on publicly available information.

The type of information compiled by this research project could provide Yosemite NP staff with up-to-date knowledge of species distributions to guide management of the park’s biological and ecological resources. Park staff could integrate the use of digital mapping tools and a GIS database of known species occurrences and distributions with management planning for special-status or indicator species in the park. A comprehensive database would also provide a means to assess “hot spots” of special-status species, which could be the focus of habitat preservation or restoration efforts within the park. The data would also identify areas where additional research is needed to obtain a more comprehensive understanding of species distributions in the park.

Staff from the U.S. Forest Service (USFS) conducted research on the distribution of forest carnivores in the Sierra Nevada, including Yosemite NP, and the southern Cascade Range and compared current distribution data with historical distribution data to assess the effects of human activities on wildlife populations (Zielinski, et al., 2005). Current data on small and mid-sized carnivores were collected using sooted track-plates and remotely triggered cameras. Historical data were synthesized from Joseph Grinnell’s book on fur-bearing mammals of California, which covered a period of 20 years between approximately 1910 and 1930. Grinnell’s data were collected primarily from trappers; therefore, the USFS research focused on the same fur-bearing mammals that were historically documented in the research area.

Zielinski, et al. (2005) mapped the results of their research and the historic distribution of the species to graphically compare the differences. The results of the USFS research revealed similar distributions for most species, modified distributions of some species, and no evidence of two species (wolverine and red fox). An interpretation of the results is that habitat generalists are less affected by human activities than habitat specialists. The lack of evidence of wolverine and red fox was expected because of historic concerns about their declining populations and their specialist requirements. Other species’ distributions were reflective of their historic distributions and ability to adapt as habitat generalists.

Staff from the USFS and University of California, Berkeley, compiled results of surveys for the fisher (Martes pennanti) to assess the species’ distribution in California (Zielinski, et al., 1995). Surveys were conducted by others between 1983 and 1995 using various methods involving tracking and cameras. The surveys were conducted from Del Norte, Humboldt, and Siskiyou counties in the north to northern Kern County, encompassing the southern Cascade Range and Sierra Nevada. The survey areas ranged in size depending on the purpose of the survey. Most surveys were conducted to determine the presence of the fisher in areas proposed for habitat alteration, such as recreational development or timber sales, while others were to support research projects.

Zielinski, et al. (1995) mapped the results of their research to display the estimated distribution of the fisher. The results of the research revealed no verifiable evidence of fisher between Shasta County and Yosemite NP. Most detections were in the northwest and on the western slope of the southern Sierra Nevada. Based on the data, it is possible that the fisher populations in California are isolated. Additional research is recommended by the authors to more accurately determine the fisher’s distribution and identify management strategies to restore populations or improve habitat connectivity. The results of the fisher study were incorporated into the broader research of mammals in the Sierra Nevada and southern Cascade Range completed by Zielinski, et al. in 2005.

Staff from the Museum of Vertebrate Zoology (MVZ) at the University of California, Berkeley, conducted surveys of a portion of Yosemite NP and adjacent areas between 2003 and 2006 to collect information on terrestrial vertebrate fauna (Moritz, 2007). The surveys used similar methodology and followed transects in most of the same areas as prior surveys conducted between 1911 and 1920 (referred to as the Grinnell survey). The purpose of the 2003-2006 survey was to resurvey the areas covered by the Grinnell survey and compare the results to describe changes in the habitat and species presence and distribution (The Grinnell Resurvey Project ). According to the authors, the results of the comparison may also be used in subsequent research to discuss the effects of global climate change on the fauna of Yosemite NP.

The surveyors used hand-drawn maps and written descriptions from the Grinnell survey to determine the locations of the previous transects or survey areas (Moritz, 2007). GPS units were used during the modern-day surveys to record GPS coordinates of the new transects, trap locations, and occurrences of some species. Following the field surveys, maps were created to show the locations of the new transects. To analyze the results of the surveys, statistical data were used to compare the modern-day survey results to the Grinnell survey results.

By comparing the results of the 2003-2006 survey with the results of the Grinnell survey, the staff at the MVZ identified changes in several species’ elevational distributions and confirmed the presence of species previously thought to be extirpated from the park (Moritz, 2007). In addition, some species observed during the Grinnell survey were not observed during the modern-day survey. Changes in vegetation communities, or habitats, were also observed and may be an underlying factor in changes in species distribution, according to the MVZ report.

The California Department of Fish and Game (CDFG) gathers and disseminates data on the status and locations of special-status species in California through the California Natural Diversity Database (CNDDB). The CNDDB is a collection of information from agencies, consultants, and the public, who submit species information to the CDFG (Bittman, 2005). The location information on species is based on survey results or documented sightings of species, with varying accuracy. When spatial information on a species is provided to the CDFG, it incorporates the information into a GIS database and the CNDDB and makes that information available to the public, agencies, and conservation organizations.

A group of conservation organizations compiled distribution and range information for numerous terrestrial mammal species in the western hemisphere (Patterson, et al., 2003). The information was compiled from a variety of literature and data sources and independent scientists. The result of this effort is a digital map library of the distributions of the mammals of the western hemisphere.

In addition to the research described above, the NPS conducts surveys of project areas throughout Yosemite NP as needed and typically associated with environmental permitting or documentation for a project. These data are not readily available via the Internet and may not be available in GIS format. The Sierra Nevada Inventory and Monitoring Program, part of the NPS, is in the process of conducting a basic inventory of the entire Yosemite NP. Part of this effort was the Grinnell re-survey project completed by the MVZ. Data and reports resulting from the inventory and monitoring efforts will be made available on the program’s website (Sierra Nevada Inventory and Monitoring Program). Because of the nature of this research project and schedule for completing it, I did not use NPS data, other than that available on its website, for this project.

For this research project, I conducted a search of the Internet to locate previous studies involving mammals and Yosemite NP (keywords); reviewed previous studies; downloaded data encompassing Yosemite NP from the NPS website and other websites; used ArcGIS 9.3 to view and create maps of mammalian species distributions in Yosemite NP; and described the results of my research in this paper. I tracked the data I obtained by creating an Excel spreadsheet to record the sources and contents of each layer. Layers that extended beyond the boundary of Yosemite NP were clipped to the park’s boundary. Maps from the background research reports were copied as images for reference in this paper.

The MVZ at UC Berkeley website provided results of surveys conducted between 2003 and 2006 as part of the Grinnell resurvey study, which included observation information for mammals observed in Yosemite NP. The observation information included the species’ scientific name, specific locality, coordinates of the observation in latitude and longitude, date of the observation, and the MVZ collection group number. The coordinates were copied into an Excel spreadsheet with the species name and a unique identification number and converted to X-Y points in ArcMap to create a shapefile and display the observations. Because of the numerous records obtained from the website (2,483 individual observations), species groups were created to display the species by large, medium, and small mammals. The observation data were displayed with base data (roads, water bodies, towns) obtained from the NPS GIS data store (http://science.nature.nps.gov/nrdata/index.cfm) to show distribution patterns in the park.

GIS data from the CNDDB were downloaded for the entire state of California and clipped to display only those occurrences in Yosemite NP. The data symbology was set up to display groups of mammals (small, medium, and bats) and not display other species. Because of the numerous records (657 individual observations and 20 different species), groups were necessary to display all the data on one map. Point data were used in lieu of polygon data for display purposes. The polygon data tend to encompass more species because they represent approximate areas where a species was detected, and not a specific point where the species was observed (coordinate information is not always available from surveys). The point data represent specific occurrences recorded with a GPS unit or other method. For comparison purposes, I overlaid the MVZ observations and CNDDB data (organized by groups) on a 1997 vegetation layer of Yosemite NP.

GIS data were downloaded from the NatureServe website and viewed in ArcMap to determine which mammals’ distribution ranges encompass Yosemite NP. The NatureServe data were not projected, so they were set up in ArcMap using the original base layer used to create the layer (ESRI’s continents layer), as identified in the data metadata. The data frame properties were set to North American Datum 1983 per the NatureServe data metadata, which ensured the distribution data displayed in the correct location. Using the results, the mammals with distributions in Yosemite NP were identified and compared to the results of other previous research discussed in this paper. The mammal range data were clipped, but only for those species that have ranges that cover a portion of the park. Other mammals with ranges that encompass the entire park were noted, but the GIS data were not used with map production. Mammals with ranges outside the park were not further considered for this project. Mammals were grouped into categories to minimize the number of species displayed on each map.

I was not able to obtain GIS data from each of the prior research studies discussed in the Background section; therefore, I was unable to create maps showing the results of all research. Maps created by the other authors were incorporated into this paper as images (not edited in ArcGIS).

The preferred format for GIS data for this project was shapefiles with a defined coordinate system. I was able to download GIS data in shapefile format from the NPS, CDFG, and NatureServe websites, but some of the data did not have a defined coordinate system. Metadata were available for most of the data; therefore, I was able to define the coordinate system and ensure the data overlay correctly. For the MVZ observation data, I was able to create a shapefile from the coordinate information and define a coordinate system consistent with the other data. The following shapefiles were downloaded and used for this research project:

• Yosemite NP boundary (boundary extracted from the NPS boundaries polygon layer)
• Yosemite NP hydrology (rivers, creeks, and lake boundaries as lines)
• Yosemite NP lakes (polygons)
• Yosemite NP roads (lines)
• Yosemite NP 1997 vegetation (polygons, clipped using the Yosemite NP boundary)
• CNDDB occurrence data for entire state of California (points, clipped using the Yosemite NP boundary)
• All mammal range data from NatureServe (polygons)

The park boundary, hydrology, lakes, and roads were used as the base layers, and the CNDDB data, mammal range data, and MVZ observation coordinates were overlaid to create individual maps. The vegetation layer was also used as a base layer to display the distribution of mammal observations in the different habitats in the park. Because data were not available for all of the previous research studies, maps from the reports were copied from the Adobe Acrobat files and saved in image format. I considered georeferencing the maps based on each map’s extent and using known coordinates, but I determined this was not necessary for purposes of presenting the information in this paper.

Mammal observations and documented occurrences from the MVZ research and CNDDB generally follow the major roads in Yosemite NP (Figures 1 and 2, respectively). A larger number of small mammal observations were reported from the MVZ research, while only a few medium-sized mammals and one larger mammal were observed in the park (Figure 1). The small mammals include mice, voles, shrews, gophers, chipmunks, and other burrowing mammals, and they occur throughout the park, with the most observations along roads and creeks. The medium-sized mammals include beaver, marten, ermine, weasel, and skunk, and they have fewer observations throughout the park. The only larger mammal observed was the mule deer, in the eastern portion of the park.

Of the special-status mammals documented in the park, bats are the largest group with the most species, and the majority of bat occurrences are along the highways and rivers in the park (Figure 2). Special-status medium-sized mammals include red fox, wolverine, beaver, badger, fisher, and marten, and most of their occurrences fall along roads, although they occur throughout the park. Special-status small-sized mammals include jackrabbit, pika, and shrew, and most of their occurrences are in the eastern portion of the park.

Figure 1. Mammal Observations from the Museum of Vertebrate Zoology Research


Figure 2. Special-Status Mammal Occurrences from the California Natural Diversity Database

Conifer habitat, which includes various pine and fir vegetation communities, is the dominant habitat in Yosemite NP, and most of the documented observations occur in this habitat type (Figure 3). Many of the observations also occur near bodies of water. Figure 3 generally shows where mammals have been observed in the park, although the data are limited to the MVZ and CNDDB data I was able to obtain. The observations encompass the wide range of habitats in the park, but the map does not portray a species-level distribution pattern by habitat in the park. Areas with multiple observations show patterns of where surveys were conducted and where the terrain is likely the most accessible for on-the-ground surveys.

Figure 3. Mammal Observations and Habitats in Yosemite National Park

Mammal distribution ranges available from the NatureServe website encompassed numerous species and the entire western hemisphere. Most of the mammals’ ranges do not overlap with Yosemite NP. Of the species whose ranges do encompass Yosemite NP, many of the species’ ranges encompass the entire park. Some of the species’ ranges partially overlap the park; these species’ ranges are displayed in Figures 4 through 8.

Carnivores and omnivores with ranges encompassing Yosemite NP include a variety of common species and some special-status species. Ringtail, red fox, bobcat, porcupine, ermine, and fisher have distributions that encompass a portion of the park, based on the NatureServe data. Several other mammals that fall in this broad category could occur throughout the park, as noted in Figure 4.

Figure 4. Carnivore and Omnivore Distribution Ranges from NatureServe

Only a few rabbits have distribution ranges encompassing Yosemite NP, and the most common jackrabbits (black-tailed and white-tailed) could occur throughout the park (Figure 5). Mountain cottontail, desert cottontail, pygmy rabbit, and snowshoe hare have distribution ranges in portions of the park, based on the NatureServe data. The American pika is another species to note in this group, and its range encompasses the entire park.

Figure 5. Rabbit Distribution Ranges from NatureServe

Mice and other rodents are likely very common in Yosemite NP, and several species have ranges encompassing all or most of the park (Figure 6). California deermouse, southern grasshopper mouse, California pocket mouse, and pinyon deermouse generally have the same distribution ranges that encompass the southwestern extent of the park. Panamint kangaroo rat, northern grasshopper mouse, and brush deermouse generally have the same distribution ranges that encompass the northeastern extent of the park. The Great Basin pocket mouse’s distribution range encompasses the majority of the park.

Figure 6. Mice Distribution Ranges from NatureServe

Gophers, chipmunks, and squirrels can generally be placed in the same group as the mice (small mammals), and all are fairly common species throughout the park. Gopher and chipmunk ranges tend to be more different and less encompassing than the mice’s ranges (Figure 7). All of the ground squirrels and several of the chipmunks have ranges that encompass the entire park.

Figure 7. Gopher and Chipmunk Distribution Ranges from NatureServe

Shrews, voles, and moles are also quite common in the park, and several of these species share similar distribution ranges (e.g., broad-footed mole, Trowbridge’s shrew, and California vole). The American water shrew and long-tailed vole have ranges that encompass the entire park.

Figure 8. Shrew, Vole, and Mole Distribution Ranges from NatureServe

Zielinski, et al. (1995 and 2005) mapped the results of their research and displayed the results in their papers. The Zielinski, et al. (1995) paper was focused on the fisher’s distribution in northern California. The results of their research show that the distribution of the species is primarily in the northwestern portion of the state, with fewer observations (or sightings) in the southern Sierra Nevada, and none in between (Figure 9). Some of these observations occur in Yosemite NP.

Figure 9. Fisher Distribution in the Sierra Nevada and Cascade Range

Zielinski, et al. (2005) incorporated the results of the 1995 fisher research and displayed a similar contemporary distribution map with the historic distribution of the fisher in the Sierra Nevada (Figure 10). The fisher’s distribution is shown as being primarily in the southern portion of the Sierra Nevada, which is more limited than the historic distribution.

Figure 10. Fisher Distribution in the Sierra Nevada

The American marten’s distribution is more scattered throughout the Sierra Nevada, with more observations displayed on the map provided in Zielinski, et al. (2005) (Figure 11). The contemporary distribution is fairly similar to the historic distribution, with a larger current distribution in the southern end of the Sierra Nevada. Several of the observations occur in Yosemite NP.

Figure 11. American Marten Distribution in the Sierra Nevada

The Sierra Nevada red fox was not observed during contemporary research, although its distribution formerly covered the Sierra Nevada, including Yosemite NP (Figure 12).

Figure 12. Sierra Nevada Red Fox Distribution in the Sierra Nevada

The wolverine was also not observed during contemporary research, although its historic distribution encompassed the southern Sierra Nevada, including Yosemite NP (Figure 13).

Figure 13. Wolverine Distribution in the Sierra Nevada

The survey data from the MVZ, occurrence data from the CNDDB, and maps produced by Zielinski, et al. (1995 and 2005) provide a general understanding of mammal distributions in Yosemite NP. Twenty-one special-status mammals have documented occurrences in the park (Table 1), and more than 30 different mammal species were observed during MVZ surveys between 2003 and 2006. Although the Sierra Nevada red fox was not detected from the Zielinski, et al. (2005) research, the CNDDB reported five occurrences in Yosemite NP. The fisher and American marten were detected in the Zielinski, et al. (2005) research, and the marten was also detected in the MVZ research. Subspecies of the fisher and marten are considered special-status (Sierra marten and Pacific fisher), and both subspecies have documented occurrences in Yosemite NP based on the CNDDB data. The combination of these data provide a better understanding of the presence and spatial distributions of different mammals in the park.

More than 70 mammals have distribution ranges that encompass all or a portion of Yosemite NP, based on the NatureServe data (Patterson, et al., 2007). These ranges were mapped at a small scale to encompass multiple countries and were not necessarily designed for spatial accuracy in an area the size of Yosemite NP. Species with partial ranges in Yosemite NP may, for example, actually occur throughout the park or not occur in the park at all. Therefore, these data would need to be combined with other research to better understand the distribution of the species in the park. The MVZ and Zielinski, et al. research in combination with the NatureServe data could provide confirmation of the presence of species with potential ranges encompassing Yosemite NP. Additional research and surveys would be needed for species identified by the NatureServe data as potentially occurring in the park, but that have not been confirmed in the park.

The NPS website was very helpful with obtaining GIS data for Yosemite NP. Not all of the data had a defined coordinate system (.prj file), although metadata were available for the data, and I was able to assign the correct coordinate system once I viewed the shapefiles in ArcGIS. I used these data as the base data and set the data frame properties consistent with the coordinate system for the data (mostly NAD83). The CNDDB data were also easy to work with, although I needed a password to download the data (available through a subscription to the CNDDB service). The data lined up accurately with the Yosemite NP data, too. I was able to easily clip the CNDDB data using the Yosemite NP boundary.

The NatureServe data were more difficult to work with because they did not have a defined coordinate system and would not line up accurately with the California state layer I obtained from the CNDDB dataset. I also had to view the entire dataset at a small scale (North and South Americas) in order to narrow down the data that overlaid California. The NatureServe metadata identified NAD83 as the appropriate coordinate system, but when I assigned it, the data would still not overlay with the California layer. Instead, I downloaded ESRI’s continents layer, which the NatureServe metadata indicated was used as the basis for creating the distribution range data. With that layer, I was able to identify those mammals with approximate distribution ranges in or near Yosemite NP. Once I narrowed down the data, I was able to overlay the ranges with the Yosemite NP boundary and identify which species have ranges that encompass the park. Then, I was able to easily clip the data with partial ranges in the park and use the results to map the data.

The MVZ website provided results of surveys in Yosemite NP (using a search query) in tabular format. The site has an export option, but I was unable to properly export the data into a useful format. Instead, I copied the data from the website and pasted them into an Excel spreadsheet. I attempted to create X-Y coordinates from the spreadsheet using ArcGIS, but the latitude-longitude information was not recognized. To fix this problem, I had to correct the spreadsheet to recognize the coordinates as numbers and delete all extra spaces at the end of each coordinate. I was then able to view X-Y data in ArcGIS using the corrected spreadsheet. This was a very time-consuming process and would have been much easier if the website’s export option worked. Once visible as points, the data lined up accurately within Yosemite NP.

Once the data were in order, I was able to create maps of the results. The CNDDB data and MVZ survey points worked well in map format with the Yosemite NP base layers. However, the NatureServe distribution range data were difficult to map due to the numerous species and extent that each species’ range overlapped. Solid polygons would not work for display purposes, and cross-hatching or dots made the data too busy. My approach, instead, was to group the species, then show solid colored boundaries for each species’ range with arrows depicting the direction the range extended. This was very time-consuming because each layer needed its own arrows and color, and the results still are difficult to interpret in map format.

Although the Zielinski, et al. (1995 and 2005) papers included maps, the original data were not readily available on the Internet. The data may be available from the authors, but I did not attempt to initiate contact with them because of the time frame of this research. If the data are available in shapefile or a GIS-compatible format, they would be useful to the NPS when compiling a geodatabase. Because the data were not available, I copied the maps provided in the electronic versions of the reports and created image files (JPEG), which are not high quality resolution and may make cross-referencing the data difficult. I also did not overlay the Yosemite NP boundary due to lack of time and efficient software (i.e., Adobe Illustrator).

The data I was able to locate were useful in understanding mammalian species’ distributions in Yosemite NP, but the data are limited to the specific research that had been conducted. The CNDDB data are limited to user input; the data include only agencies, companies, or individuals who submit spatial information to the CDFG. Other special-status species may occur in the park or have more occurrences than provided in the data, but if the CDFG is not aware of this information, it cannot produce a GIS layer showing it. The MVZ research was a repeat of early 1900s surveys of the region, so the survey areas were limited to previously surveyed areas and did not encompass the entire park. The Zielinski, et al. research was also limited to specific survey areas and was actually a compilation of previous research, which also did not encompass the entire park.

The NPS is generally familiar with the mammals that occur in Yosemite NP because it is responsible for managing the park and evaluating environmental effects of its actions in the park. Much of this information may not be new to NPS staff, but the compilation of spatial data on mammal occurrences is important to better understand each species’ distribution within the park. Because the data I used in this research were readily available on the Internet, the NPS also has access to the data. The NPS also likely has access to additional research that I was unable to locate on the Internet. The combination of all research on mammal distributions in the park should be used to create a geodatabase that provides spatial data on mammal observations and occurrences. Useful information to consider for the geodatabase includes survey boundaries, dates of surveys, species observed, coordinate information for the observation, and a unique identification number for each record. Other considerations for the geodatabase include establishing a preferred coordinate system at the onset and identifying a geodatabase manager, who will be responsible for maintaining and updating the database. Data may also need to be digitized from non-GIS sources, and the efforts to establish a geodatabase could be very time-consuming and require additional funding that the NPS may not currently have.

The data could be used to create maps, similar to those presented in this paper, for management purposes. The maps would help the NPS identify hot spots of special-status species or areas where previous surveys have not been conducted. The maps would also provide support for acquiring funding for research by providing a visual product that displays the need for additional research. They could also be distributed to research organizations to solicit interest in expanding the park’s database of mammalian research.

In summary, my research is just a small fraction of the amount of research that would be needed to compile a geodatabase of mammal observations and occurrences. Because of the species diversity in Yosemite NP, the NPS would likely be able to solicit interest in conducting additional research in the park and incorporating the results into a geodatabase to guide the park’s management of mammals. This type of research project could also be expanded to encompass more than just mammals and would provide a useful tool for the NPS to meet its management goals.

Bittman, R., 2003. The California Natural Diversity Database: A Natural Heritage Program for Rare Species and Vegetation. Fremontia, 29(3-4):57-62.

California Department of Fish and Game, 2009. Special Animals (883 taxa), July 2009. Prepared by the State of California, The Natural Resources Agency, Department of Fish and Game, Biogeographic Data Branch.

Moritz, PhD, C., 2007. Final Report: A Re-survey of the Historic Grinnell-Storer Vertebrate Transect in Yosemite National Park, California. Department of Integrative Biology, University of California, Berkeley. June.

Patterson, B. D., Ceballos, G., Sechrest, W., Tognelli, M. F., Brooks, T., Luna, L., Ortega, P., Salazar, I., and B. E. Young, 2007. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 3.0. NatureServe, Arlington, Virginia, USA.

Zielinski, W.J., Kucera, T.E., and R.H. Barrett, 1995. Current distribution of the fisher, Martes pennanti, in California. California Fish and Game, 81(3):104-112.

Zielinski, W.J., Truex, R.L., Schlexer, F.V., Campbell, L.A., and C. Carroll, 2005. Historical and contemporary distributions of carnivores in forests of the Sierra Nevada, California, USA. Journal of Biogeography, 32:1385-1407.