A Successful Predictive Model of Species Richness Based on Indicator Species

Abstract:  Because complete species inventories are expensive and time-consuming, scientists and land managers seek techniques to alleviate logistic constraints on measuring species richness, especially over large spatial scales. We developed a method to identify indicators of species richness that is applicable to any taxonomic group or ecosystem. In an initial case study, we found that a model based on the occurrence of five indicator species explained 88% of the deviance of species richness of 56 butterflies in a mountain range in western North America. We validated model predictions and spatial transferability of the model using independent, newly collected data from another, nearby mountain range. Predicted and observed values of butterfly species richness were highly correlated with 93% of the observed values falling within the 95% credible intervals of the predictions. We used a Bayesian approach to update the initial model with both the model-building and model-validation data sets. In the updated model, the effectiveness of three of the five indicator species was similar, whereas the effectiveness of two species was reduced. The latter species had more erratic distributions in the validation data set than in the original model-building data set. This objective method for identifying indicators of species richness could substantially enhance our ability to conduct large-scale ecological assessments of any group of animals or plants in any geographic region and to make effective conservation decisions.     

Innocents Abroad: Western Fantasies of Childhood and the Iconography of Emergencies

In this paper I explore the emotional interests maintained by the imagery of children used in Third World emergencies. Boundaries between adult and child are reproduced through relations of paternalism between North and South, such that the infantilisation of the South exemplified in imagery of children works to secure the competence and maturity of the Northern donor. Drawing on both analyses of the cultural origins and meanings of concepts of childhood and psychoanalytic perspectives, I suggest that media coverage of disasters arouses both identification and strategies to ward off and protect from the anxiety this brings. The gendered as well as geographical distribution of qualities of children's innocence and experience are discussed, drawing on both general imagery of children and recent coverage of children and child-saving, particularly in the former Yugoslavia. Developing analyses of 'disaster pornography', the paper explores how children appear as the principal focal objects onto which attention is pinned and as the signifiers of distress. This is at the cost of dehumanizing both children, their families and their cultures, and rendering them passive objects of a western gaze which seeks to confirm its own agency and omnipotence to ward off its own insecurities. While aid organisations and campaigns necessarily engage with, and sometimes collude with, these reactions, the paper ends by suggesting that there may be strategies whereby images of children can function to comment on rather than maintain prevailing colonial and paternalistic relations.     

Patterns of Nest Predation on Artificial and Natural Nests in Forests

Abstract:  Artificial nest experiments have been used in an attempt to understand patterns of predation affecting natural nests. A growing body of literature suggests that neither relative rates nor patterns of predation are the same for artificial and natural nests. We studied nest predation and daily mortality rates and patterns at real and artificial ground and shrub nests to test the validity of artificial nest experiments. We monitored 1667 artificial and 344 natural nests, over seven trials, in three regions, across 58 sites in Ontario. We controlled for many of the factors thought to be responsible for previously reported differences between predation rates on natural and artificial nests. Although artificial nests in our study resembled natural nests, contained eggs of appropriate size, shape, and color of target bird species, and were placed in similar microhabitats as natural nests, the rates of predation on these nests did not parallel rates on natural nests for any region in terms of absolute rate or pattern. Predation rates on artificial nests did not vary between years, as they tended to for natural nests, and the magnitude of predation pressure on artificial ground nests compared with shrub nests did not show the same pattern as that on natural nests. In general, rates of predation on artificial nests were significantly higher than on natural nests. Our results suggest that conclusions derived from artificial nest studies may be unfounded. Given that many influential ideas in predation theory are based on results of artificial nest experiments, it may be time to redo these experiments with natural nests.