Petition to list the Mohave Ground Squirrel - Defenders of Wildlife

Petition to list the Mohave ground squirrel
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location or subpopulations; number of mature individuals. There is no legal protection
provided by this IUCN status.
VI. APPLICABILITY OF LISTING FACTORS
Section 4(a)(1) of the Endangered Species Act (16 U.S.C. 1531 et seq.) and regulations (50
CFR part 424) promulgated to implement the listing provisions of the Act set forth general
listing criteria. If a species’ existence is imperiled by one or more of the following five
factors, it must be listed as “threatened” or “endangered.”
Overall, the data presented below clearly demonstrates that the Mohave ground squirrel
warrants listing under the Federal Endangered Species Act. Due to extreme sensitivity to
habitat fragmentation, the species is gone from over 20% of its range and the remainder of
the range is under intense pressure. Current regulatory mechanisms are insufficient to protect
Mohave ground squirrels in their remaining habitat or to protect that habitat from
fragmentation, degradation, or loss caused by multiple land uses.
Defenders of Wildlife and GreenInfo conducted a GIS analysis of the land-use status of
habitat within the range of the Mohave ground squirrel in 2004. The results are summarized
in Figures 6-9 and Tables 1 and 2. The maps were created by compiling data from the
Bureau of Land Management (BLM), the California Legacy Project 2003, CalVeg (USFS)
2000, Caltrans 2002, National Hydrology Dataset (USGS) 2001, California Division of Land
Resource Protection's Farmland Mapping and Monitoring Program (FMMP) 2002, and
GreenInfo 2004. Each layer was then clipped to the extent of the Mojave Ground Squirrel
range. Acreages were calculated for each of the data layers. In order to determine the
“remaining habitat” reported in Table 1, several layers were merged together in order to
create one continuous coverage. The layers that were merged together included: curtailment,
DOD lands, urban areas from CALVEG and BLM, rural development, agriculture, a 400
meter buffered zone from the center point of the major highways (US 395, SR 58, and SR
14), a 3 meter buffered zone from the center point of designated ORV routes, the Fort Irwin
Expansion and BLM Grazing Allotments. Figure 6 indicates the predominant land uses
throughout the Mohave ground squirrel range. Figure 7 documents the various threats facing
the Mohave ground squirrel. Figure 8 shows the cumulative “disturbed habitat” and
“remaining habitat” layers. The values presented in the discussions below are taken from
this GIS analysis. In total, this mapping reveals that cumulatively only 9% of the range of
the Mohave ground squirrel is in a protected and intact state.
A. Present or threatened destruction, modification, or
curtailment of habitat or range
i. Curtailment of Range
The persistence of the Mohave ground squirrel is inherently threatened due to its relatively
small range (WEMO HCP, Appendix MGS-3). As detailed above under “distribution,” the