Rank-dependent hoarding effort in willow tits (<Emphasis Type="Italic">Parus montanus</Emphasis>): a test of theoretical predictions

Many birds and mammals store energy as hoarded food supplies. A supply of stored food is beneficial during periods when food is scarce, but building up and managing such a supply also entails costs. The optimal number of caches will be reached when the net benefit is at its maximum. If dominants can steal more stored food from subordinates than the other way around, the optimum will differ between these categories. A previous theoretical model of hoarding in groups with dominant and subordinate members produced three testable predictions: (1) hoarders should store more food as anticipated future conditions get worse; (2) subordinate flock members should store more food than dominants; and (3) dominants should increase hoarding relatively more than subordinates as conditions get worse. Here we present a field experiment on willow tits (Parus montanus) designed to test these predictions. We found support for all three. Hoarding increased as conditions got worse, subordinates stored at a higher rate than dominants, and dominants increased their hoarding effort relatively more than subordinates as conditions worsened. These results support the incorporation of information on dominance and food availability into models predicting food storage behaviour.Communciated by J. Dickinson     

Bone mineral density in male Baltic grey seal (Halichoerus grypus)

Bone mineral density (mg cm(-3)) was studied in male Baltic grey seals (4-23 years of age) by noninvasive computed tomography (pQCT). The material was grouped according to year of collection. Group A: 1850-1955, a period before the main introduction of organochlorines (OCs); Group B: 1965-1985, a period with very high OC contamination; and Group C: 1986-1997, a period with decreasing concentrations of OCs. The reproducibility of the measurements was good with a Coefficient of Variation (CV) ranging from 0.1% to 2.1%. Trabecular bone mineral density of the radius was significantly higher in specimens collected 1986-1997 than in those collected 1965-1985 (p < 0.05). Cortical bone mineral density of the mandible was significantly lower in specimens collected 1986-1997 compared with those collected 1850-1955 (p < 0.05). These results indicate different responses over time in trabecular and cortical bone. During the period of very high OC contamination (1965-1985), trabecular bone density was lowest, whereas cortical bone density was lowest in specimens collected 1985-1997, representing a period of fairly low OC contamination. The mechanisms behind these effects are not known. However, it can be assumed that OCs are involved. Information about residue levels of OCs in the studied individuals is lacking and, therefore, it was not possible to evaluate the impact of OCs in this respect.     

Dealing with double-counting in tiered hybrid life-cycle inventories: a few comments – response

This paper is a response to a comment made by Lenzen [1] regarding a paper by Strømman et al. [2]. In this article I comment upon the proposals made by Lenzen. Through this, insights into challenges associated with path based methods in LCA are provided. In particular the application of these to correct for double counting in tiered hybrid LCA. A brief revisit of the rationale for the original work is provided. Key aspects of the methodology are discussed with outset in the comments in [1]. Finally, an assessment of the various approaches, including an option for further improvement is provided.     

Digit ratios (2D:4D), secondary sexual characters and cell-mediated immunity in house sparrows <Emphasis Type="Italic">Passer domesticus</Emphasis>

Homeobox genes regulate development of digits, and it has been suggested that the ratio of length of second to length of fourth digit reflects such genetic effects in a sex-specific manner. We show that digit ratios in the sexually dichromatic house sparrow Passer domesticus differ between sexes, with males having higher ratios than females, and that individuals produce consistent ratios on the two feet. If Homeobox or other genes had pleiotropic effects on development of digits, behavior, and physiology of males and females, we would expect secondary sexual characters and immunity to be related to digit ratio in a sex-specific manner. The size of the visible part of the black badge in February (a secondary sexual character), but not total badge size, was positively correlated with digit ratios, suggesting that males with more male-like digit ratios had larger visible badges. Because of sex-specific effects of development on secondary sexual characters and immunity, we predicted sex-specific differences in immune response to be related to digit ratio. House sparrows with large digit ratios had weaker T cell-mediated immune response than individuals with small digit ratios, particularly in females, implying that females with more male-like digit ratios had weak immune responses. These findings are consistent with the hypothesis that early development, as reflected by digit ratios, and genetics affect the expression of adult characters that are supposedly strongly contributing to fitness.     

A fungal perspective on conservation biology

Hitherto fungi have rarely been considered in conservation biology, but this is changing as the field moves from addressing single species issues to an integrative ecosystem‐based approach. The current emphasis on biodiversity as a provider of ecosystem services throws the spotlight on the vast diversity of fungi, their crucial roles in terrestrial ecosystems, and the benefits of considering fungi in concert with animals and plants. We reviewed the role of fungi in ecosystems and composed an overview of the current state of conservation of fungi. There are 5 areas in which fungi can be readily integrated into conservation: as providers of habitats and processes important for other organisms; as indicators of desired or undesired trends in ecosystem functioning; as indicators of habitats of conservation value; as providers of powerful links between human societies and the natural world because of their value as food, medicine, and biotechnological tools; and as sources of novel tools and approaches for conservation of megadiverse organism groups. We hope conservation professionals will value the potential of fungi, engage mycologists in their work, and appreciate the crucial role of fungi in nature. Una Perspectiva Micótica de la Biología de la Conservación     

Stakeholders on Meat Production, Meat Consumption and Mitigation of Climate Change: Sweden as a Case

In this paper we analyse and discuss the views of Swedish stakeholders on how to mitigate climate change to the extent it is caused by meat production. The stakeholders include meat producer organisations, governmental agencies with direct influence on meat production, political parties as well as non-governmental organisations. Representatives of twelve organisations were interviewed. Several organisations argued against the mitigation option of reducing beef production despite the higher greenhouse gas intensity of beef compared to pork and chicken meat (according to life cycle analysis). Regarding feed production some organisations proposed use of the best available industrial fertilizers, others were against all use of such fertilizers. Several organizations suggested domestic production of more protein-rich fodder and use of manure for biogas production. Regarding meat consumption the focus was on throwing away less food as waste and on eating less meat but the best (most climate friendly) meat, which was considered to be Swedish meat in contrast to imported meat. There was agreement on many issues. Most disagreement was found regarding political steering. We find many of the stakeholders’ mitigation proposals regarding meat production and consumption acceptable. However, we are to some extent critical to their defence of Swedish beef production. We also point out certain problems with the suggestion to reduce consumption of imported meat but not of domestically produced meat.     

Sustainable management of demolition waste—an integrated model for the evaluation of environmental, economic and social aspects

A model is presented for evaluating waste management systems for their contribution to a sustainable development, including environmental, economic and social aspects. The model was tested in a case-study, where groups of long-term unemployed people were offered both education on environmental issues and practical work with the recovery and recycling of building and demolition waste as a form of vocational development. Application of the suggested model revealed the overall effects on sustainability of different methods of waste management. In addition, negative aspects of the systems analysed were identified, which led to discussions about possible improved practices within the waste management systems. Two of the waste management systems investigated (the recycling of steel and re-use of sanitary porcelain) showed a potential contribution to sustainable development in all of the aspects studied. Preparing bricks for re-use showed the largest potential for eco-efficiency, but had negative effects on sustainability from the social perspective of health and the working environment. The possibility of further use of the model and the remaining obstacles to such analyses are discussed. One observation is that the data collection needed to perform this kind of sustainability analysis is resource-demanding, and that it would therefore be better to identify a smaller number of key indicators.     

Distribution of some trace metals and their fluxes in the Genesee River,NY

Total and particulate metal concentrations, measured during intensive synoptic studies of the Genesee River, NY, correlated with suspended-sediment concentration and river discharge. Dissolved metal concentrations, on the other hand, showed little systematic variation over the length of the river. Metal and sediment fluxes for two elevated-discharged periods peaked at a midbasin sampling site. For most metals at most sampling sties particulate materials comprised over one-half of the total material. Comparison of particulate material metal concentrations, normalized to the measured suspended-sediment concentrations had with basinwide average values shows that sites having low suspended-sediment concentrations had high particulate material metal contents relative to the basin averages, while sites with high suspended-sediment concentration had low metal contents. These results are consistent with a metal transport mechanism in the Genesee River involving (1) a nearly constant dissolved component, (2) a fine acid-soluble component, and (3) a coarse component that is effectively a neutral diluent in the sediment. Chemical factors, such as sediment organic content, also appear to affect metal transport in the Genesee River.     

The costs and benefits of a migratory species under different management schemes

This paper analyses how different management schemes influence the exploitation and economics of a wildlife population--the moose (Alces alces)--that is both a value (harvesting income) and a pest (forestry damage). Two regimes are explored; the unified management scheme where the wildlife manager aims to find harvesting quotas that maximise the overall benefit of the moose population, and the market solution where the landowners follow their narrow self-interests and maximise their private profit. Because the moose is partly a migratory species, these regimes will differ both with respect to harvesting income and browsing damage, and the landowners will experience different profit. The unified scheme is very similar to the actual Scandinavian management, while the market solution is closer to the management policy one finds in North America. In the first part of the paper it is shown how the harvesting quotas and browsing damage under these two regimes are influenced by dispersal as well as other ecological and economic factors. In the last part of the paper it is demonstrated that under the unified management regime the present practice of neglecting migration may lead to sub-optimally sized populations of migrating moose and an overall economic loss. It is also shown that neglecting migration leads to a substantial profit transfer among the landowners. The model is supported by a real life numerical example.     

Environmental threats to buried archaeological remains

The last century's environmental pollution has created health problems, acidification of ground and lakes, and serious damage to our cultural heritage. Outdoor monuments suffer from this pollution, but so do buried archaeological remains. However, research on the deterioration of archaeological artifacts underground has so far been limited, and it is important to draw attention to this neglected field. This article presents results obtained at the Swedish National Heritage Board on the degradation of archaeological objects of bronze and iron and of bones from prehistoric graves, materials of which seem to be most affected by pollutants. The investigation methods, which were employed, are described. Other relevant studies are briefly reviewed. It is obvious that the deterioration rate of archaeological artifacts, especially of inorganic materials, has accelerated in recent years, and that this increased deterioration to a large part can be attributed to anthropogenic pollution. Regions that might be endangered are exemplified.