Effects of mistletoe () on California oaks.

Mistletoes are a widespread group of plants often considered to be hemiparasitic, having detrimental effects on growth and survival of their hosts. We studied the effects of the Pacific mistletoe, , a member of a largely autotrophic genus, on three species of deciduous California oaks. We found no effects of mistletoe presence on radial growth or survivorship and detected a significant positive relationship between mistletoe and acorn production.

Which Moral Foundations Predict Willingness to Make Lifestyle Changes to Avert Climate Change in the USA?

Jonathan Haidt's Moral Foundations Theory identifies five moral axes that can influence human motivation to take action on vital problems like climate change. The theory focuses on five moral foundations, including compassion, fairness, purity, authority, and ingroup loyalty; these have been found to differ between liberals and conservatives as well as Democrats and Republicans. Here we show, based on the Cornell National Social Survey (USA), that valuations of compassion and fairness were strong, positive predictors of willingness to act on climate change, whereas purity had a non-significant tendency in the positive direction (p = 0.

Effects of load-lightening and delayed extrapair benefits on the fitness consequences of helping behavior.

In most cooperative breeders, helping is directed at close kin, allowing helpers to gain indirect fitness benefits by increasing the reproductive success of close relatives, usually their parents. Extrapair paternity (EPP) occurs at high rates in some cooperative breeders, reducing the relatedness of helpers to the young they help raise. Even so, a son that helps is related to the brood by at least 0.

Age-based discrimination of rival males in western bluebirds.

Adaptive social behavior frequently involves discriminating between classes of individuals such as relatives versus non-relatives, older versus younger individuals, or individuals of different status. In the absence of spatial cues, this discrimination may be based on signals that correlate with fitness-related traits (e.g.

Spatial distribution of oak mistletoe as it relates to habits of oak woodland frugivores.

This study addresses the underlying spatial distribution of oak mistletoe, Phoradendron villosum, a hemi-parasitic plant that provides a continuous supply of berries for frugivorous birds overwintering the oak savanna habitat of California's outer coast range. As the winter community of birds consuming oak mistletoe varies from group-living territorial species to birds that roam in flocks, we asked if mistletoe volume was spatially autocorrelated at the scale of persistent territories or whether the patterns predicted by long-term territory use by western bluebirds are overcome by seed dispersal by more mobile bird species. The abundance of mistletoe was mapped on trees within a 700 ha study site in Carmel Valley, California.

Can evolutionary design of social networks make it easier to be 'green'?

The social Web is swiftly becoming a living laboratory for understanding human cooperation on massive scales. It has changed how we organize, socialize, and tackle problems that benefit from the efforts of a large crowd. A new, applied, behavioral ecology has begun to build on theoretical and empirical studies of cooperation, integrating research in the fields of evolutionary biology, social psychology, social networking, and citizen science.

Benefits, motivations, and barriers related to environmental volunteerism for older adults: developing a research agenda.

Interest in civic engagement focused on the natural environment has grown dramatically, as has the population of older adults. Our article explores the potential for increased environmental volunteerism among older adults to enrich the lives of volunteers while benefitting the community and environmental quality. Curiously, this convergence has been relatively neglected by researchers and program developers.

Inclusive fitness theory and eusociality.

Arising from M. A. Nowak, C.

Climatic constraints on wintering bird distributions are modified by urbanization and weather.

1. Ecologists have long been interested in the role of climate in shaping species' ranges, and in recent years, this relationship has taken on greater significance because of the need for accurate predictions of the effects of climate change on wildlife populations. Bioclimatic relationships, however, are potentially complicated by various environmental factors operating at multiple spatial and temporal scales.

Ecological determinants of American crow mortality due to West Nile virus during its North American sweep.

We examined the ecological factors influencing population declines in American crows (Corvus brachyrhynchos) as they were initially exposed to West Nile virus (WNV), a pathogen first detected in the US in 1999 that has since become one of North America's most prevalent vector-borne pathogens. The strongest effects were initial crow population density (denser populations were more likely to suffer declines), avian species diversity (populations in areas with high diversity were less likely to suffer a decline), human population density (populations were more likely to decline in more urban areas), and time since the pathogen's introduction to the US (populations exposed to the pathogen later in its North American sweep were less likely to suffer declines than those exposed earlier). Variables that played only a minor role included rainfall, mean maximum temperature, and total number of birds, used as a proxy for the overall reservoir competence of the community.

Development and cross-species testing of western bluebird (Sialia mexicana) microsatellite primers.

Western and eastern bluebirds (Sialia mexicana and S. sialis) are socially monogamous passerines that engage in extra-pair copulations. We obtained microsatellites from S.

Decoding dumping ducks.

Conspecific brood parasitism, where females of the same species lay eggs in each other's nests, is common in waterfowl, and is usually considered costly to host females, which are stuck looking after eggs and chicks that are not their own. However, since female waterfowl often exhibit an unusual propensity to nest near where they were born, there has been some uncertainty over whether, in ducks and geese, laying in nests of conspecifics really is parasitism. Do parasitic and host females tend to be related? And is parasitism actually a form of cooperation in disguise? In a population in Hudson Bay, Andersson & Waldeck (this issue) found that 'parasitic' eggs in nests of the common eider, Somateria mollissima sedentaria, are more closely related to host eggs than expected by chance.

Winter resource wealth drives delayed dispersal and family-group living in western bluebirds.

Delayed dispersal, where offspring remain with parents beyond the usual period of dependence, is the typical route leading to formation of kin-based cooperative societies. The prevailing explanations for why offspring stay home are variation in resource wealth, in which offspring of wealthy parents benefit disproportionately by staying home, and nepotism, where the tendency for parents to be less aggressive and share food with offspring makes home a superior place to wait to breed. These hypotheses are not strict alternatives, as only wealthy parents have sufficient resources to share.

Family-based winter territoriality in western bluebirds, Sialia mexicana: the structure and dynamics of winter groups.

Winter residency is characteristic of the majority of cooperatively breeding birds, but the composition and dynamics of winter groups have been examined in relatively few. In 1996-1998, we examined winter territoriality in the western bluebird, a year-round resident that shows a limited degree of helping behaviour in central coastal California, U.S.