Building genetic networks using relatedness information : a novel approach for the estimation of dispersal and characterization of group structure in social animals

Natal dispersal is an important life history trait driving variation in individual fitness, and therefore, a proper understanding of the factors underlying dispersal behaviour is critical to many fields including population dynamics, behavioural ecology and conservation biology. However, individual dispersal patterns remain difficult to quantify despite many years of research using direct and indirect methods. Here, we quantify dispersal in a single intensively studied population of the cooperatively breeding chestnut-crowned babbler (Pomatostomus ruficeps) using genetic networks created from the combination of pairwise relatedness data and social networking methods and compare this to dispersal estimates from re-sighting data. This novel approach not only identifies movements between social groups within our study sites but also provides an estimation of immigration rates of individuals originating outside the study site. Both genetic and re-sighting data indicated that dispersal was strongly female biased, but the magnitude of dispersal estimates was much greater using genetic data. This suggests that many previous studies relying on mark–recapture data may have significantly underestimated dispersal. An analysis of spatial genetic structure within the sampled population also supports the idea that females are more dispersive, with females having no structure beyond the bounds of their own social group, while male genetic structure expands for 750 m from their social group. Although the genetic network approach we have used is an excellent tool for visualizing the social and genetic microstructure of social animals and identifying dispersers, our results also indicate the importance of applying them in parallel with behavioural and life history data.

Unrelated helpers neither signal contributions nor suffer retribution in chestnut-crowed babblers

Alloparental care by distant/nonkin that accrue few kin-selected benefits requires direct fitness benefits to evolve. The pay-to-stay hypothesis, under which helpers contribute to alloparental care to avoid being expelled from the group by dominant individuals, offers one such explanation. Here, we investigated 2 key predictions derived from the pay-to-stay hypothesis using the chestnut-crowed babbler, Pomatostomus ruficeps, a cooperatively breeding bird where helping by distant/nonkin is common (18% of nonbreeding helpers). First, we found no indication that distant or nonkin male helpers advertised their contributions toward the primary male breeder. Helpers unrelated to both breeders were unresponsive to provisioning rates of the dominant male, whereas helpers that were related to either the breeding male or to both members of the pair were responsive. In addition, unrelated male helpers did not advertise their contributions to provisioning by disproportionately synchronizing their provisioning events with those of the primary male breeder or by provisioning nestlings immediately after him. Second, no helper, irrespective of its relatedness to the dominant breeders, received aggression when released back into the group following temporary removal for 1-2 days. We therefore find no compelling support for the hypothesis that pay-to-stay mechanisms account for the cooperative behavior of unrelated males in chestnut-crowned babblers.

The several social constructions of James, Jenks, and Prout: A contribution to the sociological theorization of childhood

The article is intended to contribute to the ongoing debate over theorizations of childhood, especially in the terms articulated by Allison James, Chris Jenkins and Alan Prout. The article focuses on the notion of social construction as a theory of childhood. There are four valid approaches to theorizing childhood. The tribal approach treats childhood as a kind of exotic tribe with its own beliefs, practices and institutions. The social structural approach treats childhood as a structurally necessary stratum in any society. The minority group approach treats childhood as an oppressed minority group, able to some extent to represent themselves and exert quasi-political action. The socially constructed approach constitutes the sociological view of childhood. The key role played by the idea of social construction is made extremely clear in the earlier work, Constructing and Reconstructing Childhood by James and Prout. Social constructionism is said to be an interpretive approach, related historically to research on children's understanding of adult experimenters' intentions. The senses of social construction that emerge from critical psychology overlap a great deal with those articulated in the new sociology of childhood.

Book review : Managing government property assets by Olga Kaganova and James McKellar (eds)

Managing Government Property Assets, edited by Olga Kaganova and James McKellar, is reviewed.

The contagious magic of James Cook in Captain-Cook's cottage

It is widely known that the so-called Cooks' Cottage in Fitzroy Gardens, relocated from Yorkshire to Melbourne in 1934, was never inhabited by Captain James Cook. Yet a subliminal nationalism, sustained by the ancient traditions of contagious magic, feeds the conviction that the dwelling must be directly connected to Australia's foundation hero — a relic that the great man touched — or else it is meaningless. This paper tracks a sequence of managerial–interpretive strategies derived from a chronology of knowledge systems to make meanings at the cottage. It introduces evidence of the original shape of the building in its Great Ayton location, and observes the consequences on management and interpretation of an older demolition and consequent rebuilding of only half the cottage in Melbourne. Much turns on changing ideas about authenticity, as management strategies fail to engage the popular taste for a hero via the magic of faith. The result is a set of opposing principles in presenting the cottage: the role of the historical record as it has enlarged, and the desires of visitors who expect a simple connection between myth and materiality.