Continental-scale dynamics of avian influenza in U.S. waterfowl are driven by demography, migration and temperature

Emerging diseases of wildlife origin are increasingly spilling over into humans and domestic animals. Surveillance and risk assessments for transmission between these populations are informed by a mechanistic understanding of the pathogens in wildlife reservoirs. For avian influenza viruses (AIV), much observational and experimental work in wildlife has been conducted at local scales, yet fully understanding their spread and distribution requires assessing the mechanisms acting at both local, (e.g., intrinsic epidemic dynamics), and continental scales, (e.g., long‐distance migration). Here, we combined a large, continental‐scale dataset on low pathogenic, Type A AIV in the United States with a novel network‐based application of bird banding/recovery data to investigate the migration‐based drivers of AIV and their relative importance compared to well‐characterised local drivers (e.g. demography, environmental persistence). We compared among regression models reflecting hypothesized ecological processes and evaluated their ability to predict AIV in space and time using within and out‐of‐sample validation. We found that predictors of AIV were associated with multiple mechanisms at local and continental scales. Hypotheses characterising local epidemic dynamics were strongly supported, with age, the age‐specific aggregation of migratory birds in an area and temperature being the best predictors of infection. Hypotheses defining larger, network‐based features of the migration processes, such as clustering or between‐cluster mixing explained less variation but were also supported. Therefore, our results support a role for local processes in driving the continental distribution of AIV

"Back to the Future" Therapy: Its Present Relevance, Promise, and Implications

Palgi and Ben-Ezra (2010) describe an intriguing approach to the treatment of acute stress responses in persons whose memory for a recent traumatic event has not yet consolidated -- an approach they call "Back to the Future" therapy (BFT). The present article examines BFT on several dimensions: theoretical fidelity, applicability, and potential for empirical investigation. BFT shows considerable promise as a treatment for a subset of persons who experience a traumatic stressor. The greatest challenges now for users of BFT include both identifying persons most likely to benefit from BFT, and systematically evaluating the effectiveness of the approach

New Evidence of the Earliest Domestic Dogs in the Americas

The domestication of dogs likely occurred in Eurasia by 16,000 years ago, and the initial peopling of the Americas potentially happened around the same time. Dogs were long thought to have accompanied the first migrations into the Americas, but conclusive evidence for Paleoindian dogs is lacking. In this study, the direct dating of two dogs from the Koster site (Greene County, Illinois) and a newly described dog from the Stilwell II site (Pike County, Illinois) to between 10,190 and 9,630 cal BP represents the earliest confirmed evidence of domestic dogs in the Americas and individual dog burials anywhere in the world. Analysis of these animals shows Early Archaic dogs were medium sized, lived active lifestyles, and exhibited significant morphological variation. Stable isotope analyses suggest diets dominated by terrestrial C3 resources and substantial consumption of riverine fish

Separating components of detection probability in abundance estimation: an overview with diverse examples

[Extract] Estimation of population abundance of rare and elusive species critically depends on the estimation of detection probability under a particular sampling method. If we ignore the issue of animals not being available, then we obtain an estimate of the size of the available component of the population rather than the total population size. The available component may be only a small portion of the total population. In addition, this component may vary with time and with important auxiliary variables in ways that are so complex that it is unsatisfactory for monitoring the population (see Chapter 4). Animals have to be "available" to a sampling method to be detected. In many animal populations not all animals are available to be captured using a particular sampling method. There may be many reasons for this. For example, in an aerial survey of dugongs (sea cows) off the coast of Australia, some dugongs may be underwater and invisible to the observers searching for them in the aircraft. Even if animals are available, they still have to be detected. This perception process is also uncertain, so, for example, if a dugong is on the surface of the water, observers in the aircraft may still miss it. In this chapter we consider in detail a model for detection probability that accounts for the processes of availability and perception. Methodology for estimating these two components of detection probability is illustrated with three diverse examples involving aerial surveys of marine mammals (dugongs), point counts of terrestrial birds, and capture-recapture studies of terrestrial salamanders. The statistical methodology used in the three examples is very different. We will use the dugong survey as a first example of a solution to a general problem of lack of availability (Marsh and Sinclair 1989; Pollock et al.in press). We then will show that very similar conceptual problems arise in many other settings and biometricians are now seeking solutions to them.\ud \ud Two other problems we consider are (1) estimation of density of birds based on point counts in which birds are detected by their calls but birds do not always call (i.e., they are unavailable for auditory detection; Farnsworth et al. 2002); and (2) population estimation of terrestrial salamanders, which presents a similar conceptual and practical problem 'because sdamanders may be underground where they cannot be counted or captured (i.e., they are physically unavailable to capture because they are not present on the surface; Bailey et al. 2004a,b). Many formulations ignore the unavailable part of the population, but doing so may be unsatisfactory unless this component is a very small and constant part of the population