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In North America, the population genetic structure of many raptor species has been shaped by patterns of post‐glacial population expansion and anthropogenic forces, such as the widespread use of the organochlorine pesticide dichlorodiphenyltrichloroethane (DDT) during the mid‐20th century. While common themes of post‐glacial avian population expansion have emerged, little is known about the genetic impacts of DDT on raptor species that experienced a population bottleneck but were not the focus of conservation efforts. We investigated how the combination of post‐Pleistocene environmental change and the DDT‐era population bottleneck have influenced the contemporary population structure of Merlins Falco columbarius in North America. We genotyped migrating Merlins across North America (n = 272) at 23 polymorphic microsatellite loci and generated sequence data for a 569‐base‐pair segment of the mitochondrial control region. We used hierarchical analysis of molecular variance, pairwise FST/ϕST comparisons and Bayesian clustering analyses to assess genetic differentiation between individuals from eastern and western North America, distinct migratory flyways, and three recognized North American subspecies. Across all analyses, we found low or no population differentiation, suggesting that North American Merlins largely comprise one panmictic population showing evidence of a post‐glacial population expansion with little genetic differentiation detected between regions. Furthermore, we did not detect a contemporary signal of a genetic bottleneck that could have resulted from the DDT‐era population decline with the markers used in this study. Consistent with other avian species, we found a correlation between allele length variation at a microsatellite isolated from the 3′ untranslated region of the ADCYAP1 gene and migratory versus sedentary characteristics in Merlin subspecies. We detected two common mitochondrial control region haplotypes in the geographical regions sampled, a unique pattern among other widespread North American raptor species. This study furthers our understanding of the genetic and demographic history of Merlins in North America and can inform future genomic studies of this species. [ABSTRACT FROM AUTHOR]

We developed primer sets for eight di-, tri-, and tetranucleotide microsatellite loci for the threatened vernal pool fairy shrimp Branchinecta lynchi from CA, CAA, ATG, CAGA, and TAGA enriched genomic libraries. We tested primers in 74 individuals of B. lynchi from California, as well as 19 individuals from six other Branchinecta species: B. coloradensis, B. constricta, B. dissimilis, B. lindahli, B. mesovalensis, and B. oriena. The eight loci showed sufficient variability for investigations of B. lynchi evolution, population structure, and genetic diversity and may provide a new tool for assisting in delineation of management areas. [ABSTRACT FROM AUTHOR]

Abstract: Traditional subspecies classifications may suggest phylogenetic relationships that are discordant with evolutionary history and mislead evolutionary inference. To more accurately describe evolutionary relationships and inform conservation efforts, we investigated the genetic relationships and demographic histories of Buteo lineatus subspecies in eastern and western North America using 21 nuclear microsatellite loci and 375-base pairs of mitochondrial control region sequence. Frequency based analyses of mitochondrial sequence data support significant population distinction between eastern (B. l. lineatus/alleni/texanus) and western (B. l. elegans) subspecies of B. lineatus. This distinction was further supported by frequency and Bayesian analyses of the microsatellite data. We found evidence of differing demographic histories between regions; among eastern sites, mitochondrial data suggested that rapid population expansion occurred following the end of the last glacial maximum, with B. l. texanus population expansion preceding that of B. l. lineatus/alleni. No evidence of post-glacial population expansion was detected among western samples (B. l. elegans). Rather, microsatellite data suggest that the western population has experienced a recent bottleneck, presumably associated with extensive anthropogenic habitat loss during the 19th and 20th centuries. Our data indicate that eastern and western populations of B. lineatus are genetically distinct lineages, have experienced very different demographic histories, and suggest management as separate conservation units may be warranted. [Copyright &y& Elsevier]

Landscape-scale population genetic structure in vagile vertebrates was commonly considered to be a contradiction in terms whereas recent studies have demonstrated behaviour and habitat associated structure in several such species. We investigate whether landscape features influence morphological and genetic differentiation in a widespread, mobile raptor. To accurately describe genetic differentiation associated with regional landscape factors, we first investigated subspecies relationships at a continental scale. We used 17 microsatellite loci and five morphological measurements to investigate differentiation between eastern and western subspecies of red-tailed hawks ( Buteo jamaicensis) and to identify patterns between differentiation and habitat within western North America. Bayesian and frequency-based analyses of microsatellite data revealed clear distinctions between B. j. borealis (eastern) and B. j. calurus (western) samples. Furthermore, hawks sampled in Texas were stouter than those collected from the Rocky Mountains and farther west. Among western samples, birds from the Great Basin, Rocky Mountains, and Washington were significantly different in morphology than those from Oregon and California. We identified a pattern of isolation by distance among western breeding sites around the Sierra Nevada. Given the long-range dispersal capabilities of raptors, this pattern suggests that population-specific habitat preferences, corresponding with habitat breaks between eastern and western slopes of the Sierra Nevada, and/or regionally variable population densities limit migration between the Mediterranean habitat of central California and the xeric habitats of southern California and interior west. We suggest habitat preferences and regionally disparate population densities may play a role in shaping genetic structure in vagile avian taxa. [ABSTRACT FROM AUTHOR]

We developed 26 Swainson's hawk ( Buteo swainsoni) microsatellite primers from CA, AAT, CATC and GAGAA enriched genomic libraries. Primers were tested in 357 Swainson's hawks from western North America as well as seven other Buteo species. These markers will have broad application in investigations of Buteo population structure and genetic diversity. [ABSTRACT FROM AUTHOR]