Abstract
BackgroundKirtland’s warblers are the rarest songbird species in North America, rarity due in part to a reliance on early successional Jack Pine forests. Habitat loss due to fire suppression led to population declines to fewer than 200 males during the 1970s. Subsequent conservation management has allowed the species to recover to over 1700 males by 2010. In this study, we directly examine the impact that low population sizes have had on genetic variation in Kirtland’s warblers. We compare the molecular variation of samples collected in Oscoda County, Michigan across three time periods: 1903–1912, 1929–1955 and 2008–2009.ResultsIn a hierarchical rarified sample of 20 genes and one time period, allelic richness was highest in 1903–1912 sample (ar = 5.96), followed by the 1929–1955 sample (ar = 5.74), and was lowest in the 2008–2009 sample (ar = 5.54). Heterozygosity measures were not different between the 1929–1955 and 2008–2009 samples, but were lower in the 1903–1912 sample. Under some models, a genetic bottleneck signature was present in the 1929–1955 and 2008–2009 samples but not in the 1903–1912 sample.ConclusionsWe suggest that these temporal genetic patterns are the result of the declining Kirtland’s warbler population compressing into available habitat and a consequence of existing at low numbers for several decades.
Highlights
Kirtland’s warblers are the rarest songbird species in North America, rarity due in part to a reliance on early successional Jack Pine forests
Two fundamental concepts within conservation genetics are that i) genetic diversity is important for population persistence and ii) that the amount of genetic diversity is mostly determined by the effective population size (Ne), which is typically much smaller than the census size (Nc) [1]
Genetic diversity After correcting for the multiple tests, none of the loci departed from Hardy-Weinberg equilibrium, and all loci were in linkage equilibrium
Summary
Kirtland’s warblers are the rarest songbird species in North America, rarity due in part to a reliance on early successional Jack Pine forests. We directly examine the impact that low population sizes have had on genetic variation in Kirtland’s warblers. Theoretical models predict that severe reductions in population size termed as population bottlenecks, have a significant impact on the Ne, and the genetic diversity of populations, so understandably, species that have undergone bottlenecks are often the focus of genetic studies. Significant bottlenecks occurred in populations of black-footed ferrets (Mustela nigripes, n = 18, [2]) whooping cranes (Grus Americana, n = 14, [3]), and northern elephant seal (Mirounga angustirostris, n = 10-30, [4]), and all three species have low genetic variation within the contemporary populations. The genetic consequences of population bottlenecks can be directly assessed when pre-bottleneck levels of genetic variation can be measured and compared to contemporary samples. Impact genetic diversity in greater prairie chickens (Tympanuchus cupido) [7], but only influenced genetic structure in peregrine falcon (Falco peregrinus) populations [8]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
