DOI: 10.5061/dryad.r4847
title: Data from: Combining citizen science species distribution models and stable isotopes reveals migratory connectivity in the secretive Virginia rail

description: Stable hydrogen isotope (δD) methods for tracking animal movement are
 widely used yet often produce low resolution assignments. Incorporating
 prior knowledge of abundance, distribution or movement patterns can
 ameliorate this limitation, but data are lacking for most species. We
 demonstrate how observations reported by citizen scientists can be used to
 develop robust estimates of species distributions and to constrain δD
 assignments. We developed a Bayesian framework to refine isotopic
 estimates of migrant animal origins conditional on species distribution
 models constructed from citizen scientist observations. To illustrate this
 approach, we analysed the migratory connectivity of the Virginia rail
 Rallus limicola, a secretive and declining migratory game bird in North
 America. Citizen science observations enabled both estimation of sampling
 bias and construction of bias-corrected species distribution models.
 Conditioning δD assignments on these species distribution models yielded
 comparably high-resolution assignments. Most Virginia rails wintering
 across five Gulf Coast sites spent the previous summer near the Great
 Lakes, although a considerable minority originated from the Chesapeake Bay
 watershed or Prairie Pothole region of North Dakota. Conversely, the
 majority of migrating Virginia rails from a site in the Great Lakes most
 likely spent the previous winter on the Gulf Coast between Texas and
 Louisiana. Synthesis and applications. In this analysis, Virginia rail
 migratory connectivity does not fully correspond to the administrative
 flyways used to manage migratory birds. This example demonstrates that
 with the increasing availability of citizen science data to create species
 distribution models, our framework can produce high-resolution estimates
 of migratory connectivity for many animals, including cryptic species.
 Empirical evidence of links between seasonal habitats will help enable
 effective habitat management, hunting quotas and population monitoring and
 also highlight critical knowledge gaps.
description: Rallus limicola summer
 species distribution modelMedian Maxent species
 distribution model for summer Rallus limicola range. Calculated from 10
 bootstrapped replicates. SDM was corrected for spatial sampling bias using
 the bias grid method.rallus_limicola_median.ascRallus limicola summer species distribution model, standard deviationStandard deviation of Maxent species distribution model for summer Rallus limicola range. Calculated from 10 bootstrapped replicates. SDM was corrected for spatial sampling bias using the bias grid method.rallus_limicola_stddev.ascRallus limicola winter species distribution modelMedian Maxent species distribution model for winter Rallus limicola range. Calculated from 10 bootstrapped replicates. SDM was corrected for spatial sampling bias using the bias grid method.rallus_limicola_median.ascRallus limicola winter species distribution model, standard deviationStandard deviation of Maxent species distribution model for winter Rallus limicola range. Calculated from 10 bootstrapped replicates. SDM was corrected for spatial sampling bias using the bias grid method.rallus_limicola_stddev.ascStable hydrogen isotope values of spring migrants and wintering Rallus limicola of unknown originδD of feathers collected from wintering Rallus limicola on the Louisiana and Texas coastal plains and from a spring migration stopover site in the Lake Erie marshes of Ohio, USA. Contour feathers were sampled from spring migrants to determine their winter provenance and primary feathers were sampled from wintering rails to determine their previous breeding location.Rallus_limicola_stable_Istope_values.xlsxProbable breeding origins of Rallus limicola wintering in Texas and Louisiana, USAProbable breeding origins of wintering Virginia rail (Rallus limicola) inferred from feather δD and species distributions models. Wintering rails were captured on the wintering grounds at five sites along the Gulf Coast, USA: (A) Anahuac National Wildlife Refuge, Texas; (B) Grand Cote National Wildlife Refuge, Louisiana; (C) McFaddin National Wildlife Refuge, Texas; (D) Rockefeller Wildlife Refuge 2004-05, Louisiana; (E) Rockefeller Wildlife Refuge 2006; and (F) Sherburne Wildlife Management Area, Louisiana.Wintering Birds.zipProbable winter origins of spring migrants from Lake Erie region, Ohio, USAWinter provenance of migrating Virginia rails (Rallus limicola) captured at Ottawa National Wildlife Refuge (Ohio, USA), inferred from probability distributions based on stable hydrogen isotope analysis of feathers and species distributions models.BSBO_population_assingment.asc