Mate fidelity of renesting pied flycatchers Ficedula hypoleuca in relation to characteristics of the pair mates

Summary After a nesting failure, individual pied flycatchers may renest with the same or a new partner. In a 2-year study, carried out in a homogeneous habitat, we removed the clutches of a total of 124 monogamous pairs to study mate fidelity. The chance of a male obtaining a new partner if the pair bond had been broken was very low, so it would be in a male's interest to retain his original mate. Females in good condition showed a greater tendency to break the pair bond, and moved longer distances for renesting, than females in poor condition. Females that had nested in the area in a previous year were more site-tenacious, though not significantly more faithful to their mates, than those that were nesting in the area for the first time. Males that succeeded in retaining their mate were characterized primarily by having black plumage, and males from which certain feathers had been removed (=handicapped) tended to lose their mates. Females preferred the same male characteristics when they chose their mates in early spring. Hence, the decision about mate fidelity is influenced by the condition of the female and the attractiveness of her mate. Some evidence was found that male parental quality was correlated with male attractiveness.     

Chattanooga shale exploitation and the aquatic environment: The critical issues

Early identification of the critical environmental issues arising from new energy technologies is needed to ensure adequate consideration of these issues in all phases of research and development. This study examines the potential hazards to aquatic ecosystems from large-scale exploitation (190,000 Mg/day) of the Chattanooga Shale Formation, an immense reserve of oil shale and uranium in Kentucky, Tennessee, and Alabama. Using existing data on regional ecology, hydrology, mining operations, and raw and spent shale chemistry, we identified two major, related environmental issues: (1) the potential for extensive adverse effects on aquatic communities through degradation of water quality and habitat; and (2) the potential conflict between the requirements for shale exploitation, and the habitat and water quality needs of threatened or endangered species. Specific hazards to aquatic ecosystems include erosion, sedimentation, acid mine drainage, raw and spent shale leachates, and surface disposal of immense quantities of solid wastes. Twelve of 19 federally designated, threatened or endangered fish and mollusks in the shale-bearing region were identified as known or recent inhabitants of the counties believed to be most favorable for the exploitation of shale. Of these, five species occur as single populations or are limited to a single river system. The potential for adverse effects on these species is greatest in the counties near the Tennessee-Alabama state line. Future research needs include physical, chemical, and toxicological characterizations of shale leachates and studies of the transport and fate of leachable contaminants. Such research can provide the guidance necessary to minimize impacts on aquatic communities resulting from extraction, retorting, and disposal of shale.     

Guidelines for Nordic building regulations regarding indoor air quality

A subcommittee of the Nordic Committee for Building Codes has released guidelines for building regulations regarding indoor air quality, especially concerning ventilation. The main features of the guidelines, such as acceptable outdoor air quality for ventilation and minimum outdoor air flows for dwellings and offices, are presented and discussed. Mechanical ventilation is, in principle, required in all buildings including dwellings, due to the requirement of a minimum outdoor air change of 0.5 h⁻¹ and the normal highly airtight nature of new buildings. The guidelines are a basis for designing energy-efficient buildings while maintaining an indoor air quality which provides acceptable comfort and does not impair health.     

Land use issues in biomass energy planning

Land availability is a key consideration for evaluating the potential of biomass energy. This depends not only on how much land is physically suitable for growing the biomass crop, but also on the environmental implications of an energy farm and the extent to which land can be freed from competing uses. Energy planning should include inventories to realistically assess the amount of land potentially available for biomass production and the trade-offs involved in using such land for biomass farms.     

Avian flocking reduces starvation risk: an experimental demonstration

Summary Theory suggests that variance in individual food intake is lower during group foraging. Consequently, group foraging can at times reduce starvation risk. In aviary experiments using green-finches we demonstrate how intake variability decreases during group foraging because individuals use feeding by flock mates as a cue to locate food (local enhancement). Flocking preferences of greenfinches responded to variance in energy gain as predicted by theoretical models for foragers attempting to reduce starvation risk. While energy budget was positive the greenfinches were risk averse and foraged socially. Their preference shifted towards more risk prone solitary foraging when kept on a negative energy budget. We conclude that time or energy net gains are not necessary for foraging groups to form, but reductions in starvation risk may be sufficient.     

Application of the EPR spin-trapping technique for the investigation of the reactions of carbonate, bicarbonate, and phosphate anions with hydroxyl radicals generated by the photolysis of H2O2

The spin trapping technique with electron paramagnetic resonance (EPR) detection of spin adducts was applied for the investigation of the reaction of hydroxyl radicals, generated by the photolysis of hydrogen peroxide, with bicarbonate and carbonate anions. The results have been compared with those obtained for aqueous solutions of hydrogen peroxide as well as solutions containing phosphate buffers at pH values identical with those of the carbonate, and bicarbonate solutions. Both the carbonate, and bicarbonate anions quenched the hydroxyl radicals more efficiently than phosphate buffers. The effect depended on the anion concentrations, and it was most pronounced in the presence of carbonate. Rate constants for the reaction of OH with the investigated anions have been calculated. They are very close to values reported in the literature, obtained using optical detection of the carbonate and phosphate radicals.