Do female association preferences predict the likelihood of reproduction?

Sexual selection acting on male traits through female mate choice is commonly inferred from female association preferences in dichotomous mate choice experiments. However, there are surprisingly few empirical demonstrations that such association preferences predict the likelihood of females reproducing with a particular male. This information is essential to confirm association preferences as good predictors of mate choice. We used green swordtails (Xiphophorus helleri) to test whether association preferences predict the likelihood of a female reproducing with a male. Females were tested for a preference for long- or short-sworded males in a standard dichotomous choice experiment and then allowed free access to either their preferred or non-preferred male. If females subsequently failed to produce fry, they were provided a second unfamiliar male with similar sword length to the first male. Females were more likely to reproduce with preferred than non-preferred males, but for those that reproduced, neither the status (preferred/non-preferred) nor the sword length (long/short) of the male had an effect on brood size or relative investment in growth by the female. There was no overall preference based on sword length in this study, but male sword length did affect likelihood of reproduction, with females more likely to reproduce with long- than short-sworded males (independent of preference for such males in earlier choice tests). These results suggest that female association preferences are good indicators of female mate choice but that ornament characteristics of the male are also important.     

Seabird mortality induced by land‐based artificial lights

Artificial lights at night cause high mortality of seabirds, one of the most endangered groups of birds globally. Fledglings of burrow‐nesting seabirds, and to a lesser extent adults, are attracted to and then grounded (i.e., forced to land) by lights when they fly at night. We reviewed the current state of knowledge of seabird attraction to light to identify information gaps and propose measures to address the problem. Although species in families such as Alcidae and Anatidae can be grounded by artificial light, the most affected seabirds are petrels and shearwaters (Procellariiformes). At least 56 species of Procellariiformes, more than one‐third of them (24) threatened, are subject to grounding by lights. Seabirds grounded by lights have been found worldwide, mainly on oceanic islands but also at some continental locations. Petrel breeding grounds confined to formerly uninhabited islands are particularly at risk from light pollution due to tourism and urban sprawl. Where it is impractical to ban external lights, rescue programs of grounded birds offer the most immediate and employed mitigation to reduce the rate of light‐induced mortality and save thousands of birds every year. These programs also provide useful information for seabird management. However, these data are typically fragmentary, biased, and uncertain and can lead to inaccurate impact estimates and poor understanding of the phenomenon of seabird attraction to lights. We believe the most urgently needed actions to mitigate and understand light‐induced mortality of seabirds are estimation of mortality and effects on populations; determination of threshold light levels and safe distances from light sources; documentation of the fate of rescued birds; improvement of rescue campaigns, particularly in terms of increasing recovery rates and level of care; and research on seabird‐friendly lights to reduce attraction.     

Enhancing Environmental Decision-making Using Citizens' Juries

Survey techniques such as contingent valuation and opinion polls are used to develop an understanding of consumer preferences for the environment in the context of environmental decision-making. However, the exposure of weaknesses in such methods has led researchers to look to other information-gathering approaches which might enhance, complement or replace survey-based approaches. One such approach is that of the citizens' jury. A citizens' jury consists of a small group of people, selected to represent the general public rather than any interest-group or sector, which meets to deliberate upon a policy question. The paper critically evaluates the role that the citizens' jury might play in aiding environmental decision-making. Two case studies are reported where the citizens' jury process is used: first, to make recommendations on rural environmental projects in the Borders Region of Scotland; and, secondly, on meeting air quality targets in Edinburgh, Scotland. The paper concludes with recommendations on how the citizens' jury might complement other methods of environmental decision support and indicates the role that citizens' juries may play in future environmental and rural decision-making.     

Ethical Beliefs and Behaviour in Contingent Valuation Surveys

A common assumption in the economic valuation of the environment is that environmental resources can essentially be treated identically to produced goods and services in estimating welfare measures. The most critical aspect of this assumption in this regard is that individuals are willing to trade-off environmental quality changes in exchange for changes in their income. In this paper, we briefly review some of the conceptual arguments over this issue, and existing empirical evidence, before presenting the results of a new pilot study which addresses some of the possible problems in viewing the environment in this fashion.     

上海市城区典型道路行驶特征研究

对上海市城区快速干道、主干道和次于道等3种典型道路上的机动车行驶特征和交通状况进行试验和调查，得出了上海市城区各类道路上机动车行驶特征参数和交通密度。结果显示，上海市城区各类道路综合行驶特征为平均速度低，加减速频繁。其中又以主干道交通状况最差。文中的数据和结论不仅可以用于上海城市交通规划，而且对控制道路两旁机动车污染具有重要意义。