We used genome-wide single nucleotide polymorphism (SNP) data and capture-mark-recapture methods to evaluate the genetic diversity and demography within seven focal sites of the endangered San Francisco gartersnake (Thamnophis sirtalis tetrataenia). As Thamnophis sirtalis tetrataenia is listed as endangered by the U.S. Fish and Wildlife Service (USFWS), sensitive location information can be made available upon request by contacting Brian J. Halstead and/or Amy G. Vandergast.

Conversion and fragmentation of wildlife habitat often leads to smaller and isolated populations and can reduce a species’ ability to disperse across the landscape. As a consequence, genetic drift can quickly lower genetic variation and increase vulnerability to extirpation. For species of conservation concern, quantification of population size and connectivity can clarify the influence of genetic drift in local populations and provides important information for conservation management and recovery strategies. Here, we used genome-wide single nucleotide polymorphism (SNP) data and capture-mark-recapture methods to evaluate the population structure, genetic diversity and abundance of seven focal sites of the endangered San Francisco gartersnake (Thamnophis sirtalis tetrataenia), a species affected by alteration and isolation of wetland habitats throughout its distribution. We also used temporally sampled datasets to examine the magnitude of genetic change over time.

A study comparing reintroduction scenarios for the San Francisco gartersnake (Thamnophis sirtalis tetrataenia), an endangered subspecies native to San Mateo County and Santa Cruz County in northern California. Models for snake survival, growth, fecundity, and reproductive status were used to construct a demographic population model. Data are posterior distributions for demographic parameters from Markov Chain Monte Carlo sampling in hierarchical Bayesian models.

A study comparing reintroduction scenarios for the San Francisco gartersnake (Thamnophis sirtalis tetrataenia), an endangered subspecies native to San Mateo County and Santa Cruz County in northern California. Models for snake survival, growth, fecundity, and reproductive status were used to construct a demographic population model. Data are posterior distributions for demographic parameters from Markov Chain Monte Carlo sampling in hierarchical Bayesian models.

These data were collected to determine how genetic variation is arrayed across remaining populations of gnatcatchers, allowing inference about individual movement and gene flow patterns among those populations. The work focused on determining the extent to which gnatcatcher aggregations function as an interconnected metapopulation, with aggregations exchanging migrants across a fragmented landscape and freely capable of re-establishing in patches from which they have been previously extirpated. These data will be used in combination with habitat and corridor indices to determine whether genetic connectivity is facilitated by stepping stone arrays of suitable habitat, or whether birds are unable to move across unsuitable habitat regardless of distance. The genetic data will also provide information on distances that individual birds will disperse for breeding. These data were used to support the following publication:

We collected ddRADseq data using the Peterson et al. 2012 (see Methodology for full citation) protocol to study the population structure and genetic diversity of two threatened species of gartersnakes inhabiting the lower Colorado River Basin in the United States: Mogollon Narrow-headed gartersnake (Thamnophis rufipunctatus) and Northern Mexican gartersnake (T. eques megalops). Data were sequenced on an Illumina HiSeq 2500 and 4000 to generate 50 base pair sequence reads and stored as fastq files. Data were submitted to NCBI in an approved format for their database. Data are stored in the NCBI Sequence Read Archive in fastq file format and can be found at https://www.ncbi.nlm.nih.gov/sra/SRP144044 These data support the following publication: Wood, D.A., Emmons, I.D., Nowak, E.M., Christman, B.L., Holycross, A.T., Jennings, R.D., and Vandergast, A.G., 2018, Conservation genomics of the Mogollon Narrow-headed gartersnake (Thamnophis rufipunctatus) and Northern Mexican gartersnake (T. eques megalops): U.S. Geological Survey Open-File Report XXXXXXXXX

This dataset includes records of captures of San Francisco gartersnakes (Thamnophis sirtalis tetrataenia) collected at five sites from 2007 to 2020. The data include measurements of snake snout-vent length to estimate growth patterns, snake sex, and the record of all captures of individual snakes for estimating capture probability, availability for capture, and survival.

Capture-mark-recapture data from San Francisco Gartersnakes at five sites in San Mateo County, California in 2018. These data include capture histories, snout-vent lengths, and sex for individual snakes. R files included with the data fit closed capture-mark-recapture models to estimate the abundance of adult snakes at each site in 2018.

Capture-mark-recapture data from San Francisco Gartersnakes at five sites in San Mateo County, California in 2018. These data include capture histories, snout-vent lengths, and sex for individual snakes. R files included with the data fit closed capture-mark-recapture models to estimate the abundance of adult snakes at each site in 2018.

The recency of large-scale land conversion in California’s San Joaquin Desert raises the probability that the region’s numerous endemic species still retain genetic signatures of historical population connectivity. If so, genomic data can serve as a guidance tool for conserving lands that once supported habitat for gene movement. We studied the genetic structuring of the endangered blunt-nosed leopard lizard Gambelia sila, a San Joaquin Desert endemic, to (1) test whether patterns of population admixture could be used to delimit former habitat corridors in the pre-converted landscape, (2) evaluate whether restriction site associated DNA sequencing (RADseq) from a subset of samples can resolve structure at the same spatial scale as mtDNA and microsatellite data collected on the full sample, and (3) inform recovery efforts lacking direction from genetics. Cluster and tree-based analyses reveal a recent shared history between many populations that are now isolated, and that contemporary structure is linked to geophysical features that influence precipitation patterns and locations of former suitable habitat. Past hybridization with the sister species Gambelia wislizenii in southern San Joaquin Desert has generated a stable, but now-isolated population with different species identities for the mtDNA and nuclear genomes. The three marker types converged on similar themes, despite substantially fewer samples in the RADseq datasets; however, RADseq inferences were sensitive to dataset assembly filters that account for sequencing error, particularly cluster assignments. We suggest ways in which these data can be used to improve recovery efforts for G. sila and offer guidelines for RADseq dataset assembly in studies of intraspecific population structure.