Respondents to contingent valuation surveys: Consumers or citizens? Reply

The fundamental assumption of the contingent valuation method (CVM) is that responses to CV questionnaires may be interpreted as expressions of consumer preferences. The consumer preference interpretation has been challenged in recent papers arguing that willingness to pay for wildlife preservation is generated, at least in part, by ethical concerns, rather than by a view that wildlife preservation will yield any benefit to individual respondents. Some further evidence bearing upon these questions is derived from a study of forest management in Australia undertaken by the Resource Assessment Commission (RAC). The evidence supports the interpretation that respondents are acting primarily as citizens

Sustainability in Iran’s Road Transport Sector: Evaluating Strategies and Policies

Sustainable development is becoming increasingly important in the development of business strategies. Consequently, transport activities come under particular attention due to its significant role in economic development process and its impacts on the environment. Achieving sustainability in transport sector becomes more challenging given the growing demand for any kind of transport activities. The main aim of this paper is to explore the Iranian transport sector’s sustainability barriers, and evaluate the efficiency of implemented policies and strategies in order to identify the potentials of improvement. For this purpose, an overview of the country and its transport sector in terms of energy consumption and pollutant emissions, which are two main recognized sustainability issues in Iran, will be discussed at first. Then, sustainability barriers are identified. To that end, the case study approach is used, and data are collected through documents analysis and interviewing transport planning and environment management experts. Then, the detected policies and strategies and their efficiency are discussed using the view point of transport and environment management experts by Delphi technique. The research revealed that the growing rate and the age of road vehicle fleet, outdated manufacturing standards, wasteful consumption patterns, traffic and inefficiency of public transport system are the main obstacles in the way of achieving a sustainable transport system in Iran. In addition, according to the viewpoint of experts, renovating deteriorated passenger cars, obligatory vehicle inspections, expanding subway system in metropolitans, renovating public transport vehicles and motivating private sector for investment in public transport were policies who considered having better performance. It is concluded that a sustainable transport system in Iran will be achieved only in case of changing the vehicle production and fuel consumption patterns. Also passenger travel and freight distribution should be shifted to other transport mode

Visual Predators Select for Crypticity and Polymorphism in Virtual Prey

Cryptically colored animals commonly occur in several distinct pattern variants. Such phenotypic diversity may be promoted by frequency-dependent predation, in which more abundant variants are attacked disproportionately often, but the hypothesis has never been explicitly tested. Here we report the first controlled experiment on the effects of visual predators on prey crypticity and phenotypic variance, in which blue jays (Cyanocitta cristata) searched for digital moths on computer monitors. Moth phenotypes evolved via a genetic algorithm in which individuals detected by the jays were much less likely to reproduce. Jays often failed to detect atypical cryptic moths, confirming frequency- dependent selection and suggesting the use of searching images, which enhance the detection of common prey. Over successive generations, the moths evolved to become significantly harder to detect, and they showed significantly greater phenotypic variance than non-selected or frequency-independent selected controls