The effects of ecology and behavior on the evolution of coloration in Coraciiformes

What drives the evolution of plumage color in birds? Bird color is likely to be under both natural and sexual selection where natural selection may favor evolution toward crypsis or camouflage whereas sexual selection may favor evolution toward conspicuousness. The responses to selection are predicted to relate to species’ ecology, behavior, and life history. Key hypotheses have focused on habitat and light environment, breeding strategy, territoriality, and hunting behavior. We tested these potential causes of color variation in the Coraciiformes, a colorful clade of non-passerine birds, using phylogenetic comparative methods and data on chromatic and achromatic properties of plumage coloration measured from museum specimens. We found that correlates of color evolution in Coraciiformes vary across body regions and depend on the focal color property (chromatic or achromatic properties of plumage coloration). While the light environment showed widespread effects on coloration in multiple body regions for both color properties, selection pressures related to behavioral characteristics had more spatially localized effects (e.g. territoriality on achromatic properties of wing feathers and hunting strategy on chromatic properties of belly feathers). Our results reveal both general patterns that may hold across other bird clades and more nuanced effects of selection that are likely to be mediated through the visual ecology of the signaler and receiver and the behavioral characteristics of Coraciiform species

The National Wellbeing Index in the isiXhosa translation: focus group discussions on how South Africans view the quality of their society

publisher versionThe International Wellbeing Index covers two complementary measures, the Personal Wellbeing Index (PWI) and the National Wellbeing Index (NWI). The focus group study reported here tested the understanding of the NWI when translated into isiXhosa, a language spoken by 6 million South Africans, or 16% of the country’s population. A challenge for the NWI in measuring national well-being is the tendency for meaning to get ‘lost in translation’ in the wording of the instrument, owing to the disparities that exist between levels of living in developed and developing nations. The focussed discussions with native isiXhosa speakers conveyed the different shades of meaning associated with the six domains that make up the NWI. The isiXhosa keywords for the domains of social conditions, the natural environment, national security, and management of the country’s affairs (government) were readily understood, but discussants asked for further clarification of keywords for the domains relating to the economy and business. Conversations showed up the close link between personal and national well-being: discussants drew upon their personal and parochial life experiences along with their knowledge of current affairs to evaluate the nation’s quality of life. They described the social contract between citizens and their government to create a ‘caring society’ that promotes well-being across key domains of national life. Many of the reference standards used to evaluate national well-being were ones postulated to influence personal well-being (Michalos A.C, Social Indicators Research 16(4): 347–413 1985 ). The study also pointed to a potential problem for longitudinal studies if the bipolar satisfaction scale, formerly used to measure the International Wellbeing Index’s PWI and NWI, is changed to a unipolar one. Findings from this pilot study confirm the potential of the NWI as a tool for measuring national well-being cross-culturally