Data from: Local government contribution to recovery of the giant gartersnake (Thamnophis gigas)

Recovery of a threatened or endangered species usually requires
conservation and mitigation actions at the local level across the
species' entire range (i.e., geographic limits of a species'
spatial distribution). Depending on the size of the range it could involve
numerous or few jurisdictions. Under the federal Endangered Species Act an
optional off-set program allows local governments to create a Habitat
Conservation Plan (HCP) to guide mitigative actions (streamlining
permitting) and in the state of California this optionally can be
complemented by a more robust program called a Natural Communities and
Conservation Plan (NCCP). This project uses a case study of the giant
gartersnake (GGS; Thamnophis gigas), a state and federally listed
threatened endemic snake species in California’s Great Central Valley, to
demonstrate various aspects of ‘contribution to recovery’ by each county
government. ‘Recovery’ means raising the population of the species to
levels that are sustainable over time and there are various ‘conservation
standards’ associated with recovery planning: the jeopardy standard (with
or without an HCP) and the recovery standard (with an HCP-NCCP). Using GIS
technology, several spatial analyses were conducted to measure: (1) the
number and density of known occurrences of the GGS in each county, (2) the
percent of the GGS range contained by each county, (3) the percent of the
range in each county that has an HCP, an HCP-NCCP, or no HCP, and (4) the
percent of each recovery unit covered by an HCP, an HCP-NCCP, or no HCP.
Results indicate that 22 counties cover the range of the GGS, however, 11
counties will be important contributors to recovery. More than half of the
range (62%) of the GGS currently has a jeopardy standard covered by no
HCPs, 24% of the range is covered by HCPs with a jeopardy standard, and
just 14% has a recovery standard covered by an HCP-NCCP.