The interplay between habitat availability and population differentiation: a case study on genetic and morphological structure in an inland wader (Charadriiformes)

Long‐distance migrant waders breeding in the Arctic often have globally structured populations, largely because they were isolated in glacial or interstadial refugia or were restricted to fragmented coastal wetlands in winter. Conversely, inland species using continentally distributed wetlands appear to be less structured (more often panmictic), presumably because they are less likely to have been isolated by multiple refugia or by current events. We analyzed genetic variation in a widely distributed inland species, the ruff (Philomachus pugnax), sampled from seven Eurasian breeding localities, and from migration routes and wintering areas in Europe and Africa. One mitochondrial marker (N = 118) and eight nuclear microsatellites (N = 170) showed: (1) high genetic variation; (2) large genetic distances among mitochondrial (private) haplotypes within breeding populations; (3) the absence of a signature of isolation‐by‐distance; and (4) a distribution of private microsatellite alleles indicating dispersal between Scandinavia and Siberia but not between western and eastern Siberia. These results were consistent with a large refugial population during the Last Glacial Maximum, and postglacial long range expansions spreading ancestral polymorphisms, and not with a stepping‐stone model of gene flow. The divergence between breeding populations in Europe and Siberia was dated to approximately 12 000 years ago. Although genetic population structure is presently statistically non‐existent, support for evolving population structure came from analyses of geographical variation in two relevant phenotypic traits: wing length and the timing of migration. Analysis of 6077 individuals sampled on migration in 2002–08 revealed that, in each year, shorter‐winged birds migrated through significantly later than longer‐winged birds. The late‐passing birds were associated with more westerly breeding localities. In conclusion, the lack of genetic structuring in ruffs (and other inland species we examined) contrasts with strong structuring in many coastal species. This suggests that the ability to use more widely available inland habitat influences the evolution of genetic structure and the maintenance of genetic variation in waders. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 641–656.     

Climate and refugial origin influence the mitochondrial lineage distribution of weasels (Mustela nivalis) in a phylogeographic suture zone

Overarching trends can be seen in European mammalian phylogeography, yet it is clear that species responded differently depending on adaptations to past environments. We built upon previous work on the phylogeography of weasels (Mustela nivalis) in Europe by using well‐preserved museum specimens from a proposed phylogeographic suture zone. The complete cytochrome b gene was amplified from 49 individuals from present‐day Poland and analyzed with previously published data on a European scale to identify glacial refugia and infer recolonization processes. Bayesian coalescent analysis revealed the importance of the Last Glacial Maximum and the Younger Dryas in the diversification of, and demographic changes in, identified mitochondrial lineages. Our analysis, in conjunction with the available fossil data, strongly points to a Carpathian origin for one of the lineages, and further highlights the importance of this region as a refugium for European mammals. Mustela nivalis originating from this refugium appear to have a selective advantage over M. nivalis from other lineages in certain environments in the suture zone in central Europe, with climate clearly influencing the distribution of mitochondrial DNA lineages. This has important implications not only for our understanding of how past climatic events shaped the genetic architecture of species, but also how they will respond to current and future climatic changes. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 57–69.     

Observations on the Aphlebiae and Megasporangia of Stauropteris burntislandica P. Bertrand

The aphlebiae of Stauropteris burntislandica are shown to bemore complex than the simple forked processes indicated by Surange.They are variable structures and consist of a protuberance orridge bearing 5–7 appendages probably arising by dichotomousbranching; the vascular system is also branched and supplieseach large lobe of the aphlebiae with a small strand of tissueof tracheidal character. A megasporangium is described containing more than four megaspores,possibly as many as seven or eight, indicating that two tetradsmay sometimes be involved in megaspore formation.     

The influence of catchment land use on stream integrity across multiple spatial scales

1. Despite wide recognition of the need for catchment-scale management to ensure the integrity of river ecosystems, the science and policy basis for joint management of land and water remains poorly understood. An interdisciplinary case study of a river basin in south-eastern Michigan is presented. 2. The River Raisin drains an area of 2776 km², of which some 70% is agricultural land. The upper basin consists of till and outwash, and both topography and land use/cover are diverse. The lower basin consists of fine textured lake deposits, is of low relief, and land use is primarily agricultural. 3. The River Raisin basin historically was a region of oak-savannah and wetlands. It was deforested, drained and converted to farmland during the mid-nineteenth century. Human population reached a plateau at about 1880, and then underwent a second period of growth after 1950, mainly in small urban areas. More recently, the amount of agricultural land has declined and forested land has increased, in accord with a general decline in farming activity. 4. It could be suggested that the influence of land use on stream integrity is scale-dependent. Instream habitat structure and organic matter inputs are determined primarily by local conditions such as vegetative cover at a site, whereas nutrient supply, sediment delivery, hydrology and channel characteristics are influenced by regional conditions, including landscape features and land use/cover at some distance upstream and lateral to stream sites. 5. Sediment concentrations measured during low flows were higher in areas of greater agriculture. In a comparison of two subcatchments, sediment yields were up to ten times greater in the more agricultural location, in response to similar storm events. A distributed parameter model linked to a geographical information system predicted that an increase in forested land cover would result in dramatic declines in runoff and sediment and nutrient yields. 6. Habitat quality and biotic integrity varied widely among individual stream sites in accord with patterns in land use/cover. Extent of agricultural land at the subcatchment scale was the best single predictor of local stream conditions. Local riparian vegetation was uncorrelated with overall land use and was a weak secondary predictor of habitat quality and biotic integrity. 7. Investigation of the regulatory agencies involved in land and water management in the basin revealed a complex web of overlapping political jurisdictions. Most land-use decision-making occurs at the local level of township, city or village. Unfortunately, local decision-making bodies typically lack the information and jurisdictional authority to influence up- and downstream events.     

Testing hypotheses of speciation in the Plethodon jordani species complex with allozymes and mitochondrial DNA sequences

Salamander populations of the Plethodon jordani species complex form a challenging system for applying the general lineage concept of species to diagnose population-level lineages. The present study reports and analyses mitochondrial-DNA haplotypes (∼1200 nucleotide bases from the genes encoding ND2, tRNA^Trp, and tRNA^Ala from 438 salamanders) from 100 populations representing six species of the P. jordani complex ( Plethodon amplus , Plethodon cheoah , Plethodon jordani , Plethodon meridianus , Plethodon metcalfi , and Plethodon montanus ) with comparative analyses of previously published allozymic data to reconstruct the evolutionary history of this group and to diagnose species lineages. Analyses of mitochondrial haplotypic data include nested-cladistic analysis of phylogeography, analysis of molecular variance, hierarchical analysis of nucleotide-diversity measures, and likelihood-based estimates of recent temporal changes in population size. New analyses of allozymic data include multidimensional scaling and principal component analyses, and both data sets are analysed and compared for congruent genetic structure using Mantel correlation tests. These analyses in combination identify the six named species as distinct evolutionary lineages despite sporadic genetic exchanges among them and some discordance between mitochondrial DNA and allozymic markers. Sexual isolation is not complete for any pair of these six species, but they replace each other geographically and appear to block the geographical spreading of their neighbours. The P. jordani complex is a strong study system for investigating the genetic and ecological processes responsible for vicariant speciation.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 25–51.     

Tired of Weeping: Mother Love, Child Death, and Poverty in Guinea-Bissau

Tired of Weeping: Mother Love, Child Death, and Poverty in Guinea-Bissau. Jónina Einarsdóttir. Madison: University of Wisconsin Press, 2005. 236 pp.     

Changes in the cryptogam flora of the Wealden sandrocks, 1688–1984

The cryptogam flora of 15 sandrock sites in the central Weald, U.K. was assessed and compared with previous records beginning in 1688. A total of 264 species was recorded (29 algae, 90 lichens, 165 bryophytes and eight ferns) of which 18 lichens, 21 bryophytes and one fern were not relocated. Air pollution, changes in the microclimate brought about by invasion of trees and shrubs and trampling appear to be the main cause for the decline in the flora, although over-collection of rarities was also a factor.     

Insecticidal sugar baits for adult biting midges

The mixing of an insecticide with sugar solution creates an oral toxin or insecticidal sugar bait (ISB) useful for reducing adult insect populations. The ability of ISBs to kill the biting midge Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae), a vector of bluetongue virus, epizootic hemorrhagic disease and vesicular stomatitis viruses, was tested. The commercial insecticide formulations (percentage active ingredient) tested included bifenthrin, cyfluthrin, deltamethrin, permethrin, dinotefuran, imidacloprid, thiamethoxam and spinosad. Mortality rates were determined for various concentrations of commercial formulations (0.01, 0.05, 0.1, 1, 2 and 3%) and observed at 1, 4, 10 and 24 h post‐exposure to the ISB. In the first set of assays, laboratory‐reared midges were fed sugar ad libitum and then exposed to insecticide‐treated sugar solutions to measure mortality. The second assay assessed competitive feeding: midges were provided with a control sugar solution (10% sucrose) in one vial, and a sugar and insecticide solution in another. Pyrethroid treatments resulted in the greatest mortality in the first hour at the lowest concentrations and spinosad consumption resulted in the least mortality. Biting midges were not deterred from feeding on the 1% ISB solutions despite the presence of an insecticide‐free alternative source of sugar.     

Assessing the impacts of wind farms on birds

The potential effects of the proposed increase in wind energy developments on birds are explored using information from studies of existing wind farms. Evidence of the four main effects, collision, displacement due to disturbance, barrier effects and habitat loss, is presented and discussed. The consequences of such effects may be direct mortality or more subtle changes to condition and breeding success. The requirements for assessing the impact of future developments are summarized, including relevant environmental legislation and appropriate methods for undertaking baseline surveys and post-construction monitoring, with particular emphasis on the rapidly developing area of offshore wind farm assessments. Mitigation measures which have the potential to minimize impacts are also summarized. Finally, recent developments in the monitoring and research of wind energy impacts on birds are outlined and some areas for future work are described.     

A DUAL TASTE FOR SACCHARIN IN THE RAT: II. Taste Change Following Alloxan Injection

It has previously been proposed that saccharin has a dual tasefor the rat, that is has both sweet and aversive componentsto its taste, and that the aversion shown to saccharin by alloxandiabetic rats might be accounted for by the diabetes reducingthe effectiveness of the sweet component. In this study it isshown that the generalization to saccharin of a conditionedaversion to glucose is reduced or eliminated following alloxantreatment suggesting that the sweet component is reduced, andthat the generalization of a conditioned aversion to quinineis enhanced suggesting that the second component of the saccharintaste is quinine-like. ^* Supported by National Research Council of Canada Grant #APO-97