Female mate choice in the Pied Flycatcher Ficedula hypoleuca

Summary We have examined male and territorial factors which might influence female mate choice in the Pied Flycatcher (Ficedula hypoleuca). Mating success of males was largely determined by the order of arrival on the breeding grounds. Females actively selected those males that had been longest in the area. This is likely to be due to territorial cues, early males having the best territories. About 15% of the males become polygynous, and these are the males that arrived earliest.Male age was relatively unimportant for breeding success, but because old males tend to arrive earlier than yearlings, most polygynous males were old. On average, old males are somewhat darker than young males, but male colour also varies within males of the same age. Polygynous and monogamous males did not differ significantly in colour, and female breeding success was not correlated with the colour of their mates. We show theoretically that it does not pay for females to select young males to avoid polygyny unless polygyny frequency or the number of reliable monogamous males almost double. Hence our hypothesis of polygyny-by-deceit in the Pied Flycatcher remains realistic. Because of male polyterritoriality, females are unaware of the males' status when mating.     

Extra-pair paternity and male characteristics in the pied flycatcher

The pied flycatcher (Ficedula hypoleuca) is sexually dichromatic with extreme variation in male plumage coloration. The benefit for males of having black plumage is controversial, and few studies have found evidence for a sexual selection benefit of being black rather than brown. However, blacker males may be better able to achieve extra-pair fertilizations (EPFs), which may be an important component of sexual selection. We studied the role of EPFs in sexual selection in the pied flycatcher by establishing a set-up where two males with different back coloration (blacker vs browner) bred simultaneously near each other. DNA fingerprinting analysis revealed that 11% of offspring resulted from EPFs, and that 22% of broods included extra-pair young (EPY) among 36 nests containing 223 nestlings. We found no evidence that browner males suffered more often from EPFs than blacker males. There was no correlation of male or female morphology or age with EPF frequency. However, breeding pairs with low genetic similarity had EPY in their nests significantly more often. Thus we argue that females paired with genetically dissimilar males may try to avoid the effects of extreme outbreeding by seeking extra-pair copulations (EPCs). Alternatively, incompatibility between genetically dissimilar mates may simply expose females to more extra-pair copulations.     

Serum concentrations of perfluorooctanesulfonate and other fluorochemicals in an elderly population from Seattle, Washington

Perfluorooctanesulfonyl fluoride (POSF, C₈F₁₇SO₂F) related-materials have been used as surfactants, paper and packaging treatments, and surface (e.g., carpet, textile, upholstery) protectants. A metabolite, perfluorooctanesulfonate (PFOS, C₈F₁₇SO₃⁻), has been identified in the serum and liver of non-occupationally exposed humans and wildlife. Because of its persistence, an important question was whether elderly humans might have higher PFOS concentrations. From a prospective study designed to examine cognitive function in the Seattle (WA) metropolitan area, blood samples were collected from 238 dementia-free subjects (ages 65–96). High-pressure liquid chromatography-electrospray tandem mass spectrometry determined seven fluorochemicals: PFOS; N-ethyl perfluorooctanesulfonamidoacetate; N-methyl perfluorooctanesulfonamidoacetate; perfluorooctanesulfonamidoacetate; perfluorooctanesulfonamide; perfluorooctanoate; and perfluorohexanesulfonate. Serum PFOS concentrations ranged from less than the lower limit of quantitation (3.4 ppb) to 175.0 ppb (geometric mean 31.0 ppb; 95% CI 28.8–33.4). An estimate of the 95% tolerance limit was 84.1 ppb (upper 95% confidence limit 104.0 ppb). Serum PFOS concentrations were slightly lower among the most elderly. There were no significant differences by sex or years residence in Seattle. The distributions of the other fluorochemicals were approximately an order of magnitude lower. Similar to other reported findings of younger adults, the geometric mean serum PFOS concentration in non-occupational adult populations likely approximates 30–40 ppb with 95% of the population’s serum PFOS concentrations below 100 ppb.     

Gravity currents in rotating,wedge-shaped,adverse channels

Results are presented from a series of parametric experimental and analytical studies of the behaviour of dense gravity currents along rotating, up-sloping, wedge-shaped channels. High resolution density profile measurements at fixed cross- and along-channel locations reveal the outflowing bottom gravity currents to adjust to quasi-steady, geostrophically-balanced conditions along the channels, with the outflow layer thickness and cross-channel interface slope shown to scale with the inlet Burger number for all experimental conditions tested. A general analytical solution to the classic rotating hydraulics problem has been developed under the assumption of inviscid, zero-potential-vorticity conditions to model dense water flow through a triangular constriction and thus simulate the vee-channel configurations under consideration. Predictions from this zero-PV model are shown to provide good overall quantitative agreement with experimental measurements obtained both under hydraulically-controlled conditions at the channel exit and for subcritical conditions generated along the channel length. Quantitative discrepancies between measurements and analytical predictions are attributed primarily to assumptions and limitations associated with the zero-PV modelling approach adopted, as well as the to the rapid adjustment in outflow characteristics as the channel exit is approached, as characterised by the along-channel variation in densimetric Froude number for the outflows.     

GIS-based niche modeling for mapping species' habitat

Ecological "niche modeling" using presence-only locality data and large-scale environmental variables provides a powerful tool for identifying and mapping suitable habitat for species over large spatial extents. We describe a niche modeling approach that identifies a minimum (rather than an optimum) set of basic habitat requirements for a species, based on the assumption that constant environmental relationships in a species' distribution (i.e., variables that maintain a consistent value where the species occurs) are most likely to be associated with limiting factors. Environmental variables that take on a wide range of values where a species occurs are less informative because they do not limit a species' distribution, at least over the range of variation sampled. This approach is operationalized by partitioning Mahalanobis D2 (standardized difference between values of a set of environmental variables for any point and mean values for those same variables calculated from all points at which a species was detected) into independent components. The smallest of these components represents the linear combination of variables with minimum variance; increasingly larger components represent larger variances and are increasingly less limiting. We illustrate this approach using the California Gnatcatcher (Polioptila californica Brewster) and provide SAS code to implement it.     

A Systems Thinking Approach to Environmental Follow-Up in a Swedish Central Public Authority: Hindrances and Possibilities for Learning from Experience

This study analysed the environmental follow-up of a public organisation from a systems thinking approach, including follow-up within different phases of operation and with different environmental management tools. The Swedish Rail Administration (SRA), a public authority responsible for Swedish rail infrastructure, was used as a case organisation. The main aim was to identify different follow-up activities during planning, construction and operation of rail infrastructure. Additional aims were to identify limiting factors for effective environmental follow-up and to provide suggestions on how SRA follow-up can better be used as an organisational learning tool. The follow-up proved to be highly influenced by Environmental Management System and was mainly used for showing compliance with legal regulations or contract requirements. Use of environmental monitoring data was limited to the specific project in which the follow-up was carried out, possibly because of the project-based structure of the organisation following rail deregulation. Theory on organisational learning was applied in the study to discuss how to improve the distribution and use of follow-up data. A more complete ‘organisational memory’ seems to be required for learning from experience and adapting to change.     

Evaluation of Urban Sustainability in Specific Sectors in Latvia

In Latvia, the concept of sustainability is only slowly gaining recognition. An analysis of Development Plans prepared by the four largest cities of Latvia indicates that sustainability is presented as one of the guiding principles. However, a comparison of Development Plan policies against the urban sustainability issues reveals a great deal of ambiguity and contradiction.At the municipal level, planners and politicians lack indicators to gauge whether the long-term goals of Development Plans and the principles of sustainable development are being achieved. As a consequence, the broad public is deprived of the opportunity to assess for itself the process of development in relation to Development Plan policies, thus limiting accountability in development decision-making. Relevant statistical data collected on a regular basis are required to create sustainability indicators reflecting sustainability issues, to supplement and replace existing statistical compilations pertaining almost exclusively to economic growth and consumption. Development and utilisation of sustainability indicators can be an effective instrument for promoting the values of sustainable development amongst politicians, planners and the broad public and for enhancing accountability in decision-making.