|
Population Genetics of American Kestrels Across their Range
Active
The American Kestrel is the smallest and the most widespread North American falcon. It inhabits open areas covered by short ground vegetation and utilizes pre-existing natural cavities for nesting, which appears to limit its population across much of the breeding range. Four North American subspecies have been identified: F. s. sparverius (most of N. American range, except southeastern. U.S. and coastal northwest), F. s. phalaena (desert southwest), F. s. paulus (southeast U.S.) and F. s. peninsularis ( southern Baja CA.). The southeastern Kestrel (F. s. paulus), which has been in decline throughout its range and has lost more than 80 percent of its critical habitat, was listed as Threatened in Florida in 1996. These subspecies designations may be based largely on a size clinal and their validity may need re-evaluation. Verification of these subspecies and their geographic limits will be valuable for providing a more quantitative basis for future listing and conservation efforts
Using mtDNA analysis, we will achieve the following objectives:
A. Determine subspecies limits for the four subspecies of American Kestrel. Determining these limits will provide a more quantitative basis for listing of the Southeastern Kestrel if needed, under the Endangered Species Act.
B.Characterize genetic diversity in a number of populations to determine if the southeast subspecies is depauperate relative to other species.
C. Examine genetic distances and differences among populations of American Kestrels. This will provide guidance regarding translocation
options, if needed, to replenish the Southeastern Kestrel population/gene pool.
We have been collecting samples for several years and currently have more than 140 samples from 9 states and provinces throughout the range of the American Kestrel. These samples include 37 samples from the range of F. s. paulus. We will get additional paulus samples next summer as part of Jeff Walters and John Parrish’s ongoing field work. Samples will be analyzed using variable markers/sequences from the control region of the mtDNA. Currently, there are no specific Kestrel markers but there are numerous mtDNA markers for the genus Falco, Partners include Dr. Jeffrey Walters (Virginia Tech) and Dr. John Parrish (Georgia Southern University). Dr. Haig supervises the USGS FRESC Conservation Genetics Lab and has been involved with conservation genetics and other endangered species research and recovery in the southeast for many years. Dr. Walters has been involved in similar work and is now focusing on the status of American Kestrels in Florida (Falco sparverius paulus). Dr. Parrish is an expert on kestrels and has spent much of his professional life working on the Paulus subspecies. The information from this project will be shared with FWS in Region 4 as they consider the Paulus subspecies for listing under ESA. hence marker development should be straightforward.
For analysis, ARLEQUIN version 2.0 will be used to determine total number of haplotypes, polymorphic sites, haplotype diversity (h), nucleotide diversity (p), and tests of assumptions of neutrality for mtDNA mutations by Tajima’s D will be performed. Population differentiation will be calculated and molecular variance analysis will be performed using (AMOVA) at different hierarchical levels (within, among population, regions and subspecies). Mitochondrial DNA population structuring will be assessed by calculating pairwise FST values. Associations between population Euclidean geographical and pairwise genetic distances will be assessed by nonparametric Mantel tests. To discriminate between recurrent and historical gene flow nested clade analysis will be performed using the programs TCS 1.13 and GeoDis 2.0.
Haig, Susan M. - Supervisory Research Wildlife Biologist
Phone: 541-750-7482
Email: susan_haig@usgs.gov
 |
