DOI: 10.25338/b82p7n
title: Data from: Local government contribution to recovery of the giant gartersnake (Thamnophis gigas)

description: 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.
description: Spatial analyses were performed using ArcGIS version 10.5.1 and
 therefore any software version equal to or later than it will be able to
 view the files using the project file “Greco GGS GIS Data.mxd.” The ‘Clip’
 function was used to extract the percent of GGS range contained in each
 county. The map overlay function ‘Union’ was used to spatially composite
 the GGS range map, the counties, and the conservation plan boundaries
 (HCPs and NCCPs).  The map overlay function ‘Union’ was also used to
 spatially composite the conservation plan boundaries (HCPs and NCCPs) and
 the recovery units. The GGS known occurrences analysis using the
 California Natural Diversity Database (CNDDB) data was performed using two
 techniques: a density map and a spatial join. The density map was created
 using the Spatial Analyst tool ‘Point density’ with a 1
 km<sup>2</sup> (1000 m x 1000 m) cell size and a 5 km radius.
 The point count for each county was done using a spatial join between the
 CNDDB GGS point data and the California counties vector layer.
description: The following 16 files are
 included in this package. Note: Numbers in parentheses to the right of the
 equal sign refer to the numbered data sets to the left of the equal
 sign. Greco GGS GIS Data.mxd = ArcGIS v.
 10.5.1 ArcMap Project file (set to relative paths)
 countyalb83.shp = California counties shapefile
 GGS_range_map_R079.shp = giant gartersnake geographic range map
 shapefile GGS_recovery_units_alb83.shp = recovery
 units shapefile for the giant gartersnake
 GGS_recovery_units_dissolve.shp = recovery units outside
 boundary shapefile GGS_data_and_labels.gdb = a
 geodatabase with two feature classes (7) and (8) and two annotation layers
 (9) and (10)—see below
 GGS_recovery_units_HCP_NCCP_Union = map union of (4) and
 (8) HCP_NCCP_in_Central_Valley_only_gdb = shapefile
 of all HCPs and NCCPs in the Central Valley in California
 HCP_NCCP_in_Central_Valley_only_gdbAnno = map labels
 HCP_NCCP_in_Central_Valley_only_gdbAnno2 = map labels
 union_HCP_county_GGS_new.shp = shapefile of map union of (2),
 (3), and (8) union_GGS_recovery_units.shp = shapefile
 of map union of (3) and (4) GGS_county_clip_new.shp =
 shapefile of (2) clipped with (3)
 GGS_county_clip_new_join2.shp = shapefile of (13) spatially
 joined with the CNDDB point data (point data are not included due to
 restrictions—see ‘Note’ below) 1km5kmsqkm = raster
 output layer of the point density map of GGS CNDDB point data (point data
 are not included due to restrictions—see ‘Note’ below) Giant Gartersnake Density.lyr =
 symbolized output of (15) classified using quantiles with six
 classes. Note: I am not permitted to
 distribute the GGS CNDDB point data. Those data are licensed through the
 California Department of Fish and Wildlife.