DOI: 10.5061/dryad.hmgqnk9mf
title: Data for: Inferring population connectivity in Eastern Massasauga Rattlesnakes (Sistrurus catenatus) using landscape genetics

description: Assessing the environmental factors that influence the ability of a
 threatened species to move through the landscape can be used to identify
 conservation actions that connect isolated populations. However, direct
 observations of species’ movement are often limited making the development
 of alternate approaches necessary. Here we use landscape genetic analyses
 to assess the impact of landscape features on the movement of individuals
 between local populations of a threatened snake, the Eastern Massasauga
 Rattlesnake (Sistrurus catenatus). We linked connectivity data with
 habitat information from two landscapes of similar size: a large region of
 unfragmented habitat and a previously studied fragmented landscape
 consisting of isolated patches of habitat. We used this analysis to
 identify features of the landscape where modification or acquisition would
 enhance population connectivity in the fragmented region. We found
 evidence that current connectivity is impacted by both contemporary
 landcover features, especially roads, and inherent landscape features such
 as elevation. Next, we derived estimates of expected movement ability
 using a recently developed pedigree-based approach and Least Cost Paths
 through the unfragmented landscape. We then used our pedigree and
 resistance map to estimate resistance polygons of the potential extent for
 S. catenatus movement in the fragmented landscape. These polygons identify
 possible sites for future corridors connecting currently isolated
 populations in this landscape by linking the impact of future habitat
 modification or land acquisition to dispersal ability in this species.
 Overall, our study shows how modeling landscape resistance across
 differently fragmentated landscapes can identify habitat features that
 affect contemporary movement in threatened species in fragmented
 landscapes and how this information can be used to guide mitigation
 actions whose goal is to connect isolated populations.
description: Dataset is
 ddRADseq from 99 individual <em style="font-family:KievitWeb , sans-serif;">Sistrurus
 catenatus </em>(Eastern Massasauga Rattlesnake) captured at Killdeer
 Plains Wildlife Area in Central Ohio, USA from 2006-2019. Individuals were
 sequenced on Illumina HiSeq2500 and HiSeq4000 platforms, using single-end
 reads size selected from 300-600bp using EcoR1 and Pst1 for our
 restriction enzymes. Reads were aligned against a reference genome using
 ipyrad, and filtering done in PLINK 2.0, with 1481 loci called in every
 individual. No missing values
 should be present in the data. All loci are bi-allelic, and anonymized
 survey sites linked to sample names have been uploaded in a separate
 document. Due to concerns over the sensitive nature of these sites, no GPS
 coordinates or morphometric data are reported. All <em style="font-family:KievitWeb , sans-serif;">S.
 catenatus</em> in this dataset came from Wyandot County, Ohio, USA.
 Rscripts have been uploaded as examples to follow, but due to removed
 location and morphology data, cannot be
 run.
description: R is required to access the scripts, and we recommend using
 RStudio. The package ResistanceGA also requires Julia to be installed with
 the current setting. All packages used were accessed either via cran
 repository or GitHub.