A Century of Landscape Disturbance and Urbanization of the San Francisco Bay Region affects the Present-day Genetic Diversity
of the California Ridgway s Rail (Rallus obsoletus obsoletus)
Dataset Identification:
Resource Abstract:
<p>Fragmentation and loss of natural habitat have important consequences for wild populations and can negatively affect long-term
viability and resilience to environmental change. Salt marsh obligate species, such as those that occupy the San Francisco
Bay Estuary in western North America, occupy already impaired habitats as result of human development and modifications and
are highly susceptible to increased habitat loss and fragmentation due to global climate change. We examined the genetic variation
of the California Ridgway s rail ( <em>Rallus obsoletus obsoletus</em>), a state and federally endangered species that occurs
within the fragmented salt marsh of the San Francisco Bay Estuary. We genotyped 107 rails across 11 microsatellite loci and
a single mitochondrial gene to estimate genetic diversity and population structure among seven salt marsh fragments and assessed
demographic connectivity by inferring patterns of gene flow and migration rates. We found pronounced genetic structuring among
four geographically separate genetic clusters across the San Francisco Bay. Gene flow analyses supported a stepping stone
model of gene flow from south-to-north. However, contemporary gene flow among the regional embayments was low. Genetic diversity
among occupied salt marshes and genetic clusters were not significantly different. However, we detected low effective population
sizes and significantly high relatedness among individuals within salt marshes. Preserving genetic diversity and connectivity
throughout the San Francisco Bay may require attention to salt marsh restoration in the Central Bay where habitat is both
most limited and most fragmented. Incorporating periodic genetic sampling in to the management regime may help evaluate population
trends and guide long-term management priorities.<br> <br> These data support the following in-press publication: Wood,
D.A., Bui, T.D., Overton, C.T., Vandergast, A.G., Casazza, M.L., Hull, J.M., and Takekawa, J.Y. Conservation Genetics
(2016). doi:10.1007/s10592-016-0888-4. </p>
Citation
Title A Century of Landscape Disturbance and Urbanization of the San Francisco Bay Region affects the Present-day Genetic Diversity
of the California Ridgway s Rail (Rallus obsoletus obsoletus)
other Citation Details
Cinergi keyword enhanced.File generated at Wed Dec 05 04:10:06 UTC 2018
purpose:
We sampled a representative number of California rail populations throughout the San Francisco Bay region and combined microsatellite
genotyping analyses to: (1) assess the occurrence of genetic differentiation among saltmarsh fragments currently occupied
by the California rail, and (2) measure demographic connectivity by inferring patterns of historical and contemporary gene
flow.
The authors of these data require that data users contact them regarding intended use and to assist with understanding limitations
and interpretation. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality
standards relative to the purpose for which the data were collected. Although these data and associated metadata have been
reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed
or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes,
nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive
purposes only and does not imply endorsement by the U.S. Government.