The interplay of colour and bioacoustic traits in the differentiation of a Southeast Asian songbird complex.

Morphological traits have served generations of biologists as a taxonomic indicator, and have been the main basis for defining and classifying species diversity for centuries. A quantitative integration of behavioural characters, such as vocalizations, in studies on biotic differentiation has arisen more recently, and the relative importance of these different traits in the diversification process remains poorly understood. To provide a framework within which to interpret the evolutionary interplay between morphological and behavioural traits, we generated a draft genome of a cryptic Southeast Asian songbird, the limestone wren-babbler Napothera crispifrons. We resequenced whole genomes of multiple individuals of all three traditional subspecies and of a distinct leucistic population. We demonstrate strong genomic and mitochondrial divergence among all three taxa, pointing to the existence of three species-level lineages. Despite its great phenotypic distinctness, the leucistic population was characterized by shallow genomic differentiation from its neighbour, with only a few localized regions emerging as highly diverged. Quantitative bioacoustic analysis across multiple traits revealed deep differences especially between the two taxa characterized by limited plumage differentiation. Our study demonstrates that differentiation in these furtive songbirds has resulted in a complex mosaic of colour-based and bioacoustic differences among populations. Extreme colour differences can be anchored in few genomic loci and may therefore arise and subside rapidly.

Simultaneous-count models to estimate abundance from counts of unmarked individuals with imperfect detection.

We developed a method to estimate population abundance from simultaneous counts of unmarked individuals over multiple sites. We considered that at each sampling occasion, individuals in a population could be detected at 1 of the survey sites or remain undetected and used either multinomial or binomial simultaneous-count models to estimate abundance, the latter being equivalent to an N-mixture model with one site. We tested model performance with simulations over a range of detection probabilities, population sizes, growth rates, number of years, sampling occasions, and sites. We then applied our method to 3 critically endangered vulture species in Cambodia to demonstrate the real-world applicability of the model and to provide the first abundance estimates for these species in Cambodia. Our new approach works best when existing methods are expected to perform poorly (i.e., few sites and large variation in abundance among sites) and if individuals may move among sites between sampling occasions. The approach performed better when there were >8 sampling occasions and net probability of detection was high (>0.5). We believe our approach will be useful in particular for simultaneous surveys at aggregation sites, such as roosts. The method complements existing approaches for estimating abundance of unmarked individuals and is the first method designed specifically for simultaneous counts.

Modelos de Conteo Simultáneo para Estimar la Abundancia a partir de Conteos de Individuos No Marcados con Detección Imperfecta Resumen Desarrollamos un método para estimar la abundancia poblacional a partir de conteos simultáneos de individuos sin marcaje en múltiples sitios. Consideramos que en cada ocasión de muestreo los individuos de una población podrían ser detectados en uno de los sitios de censos o podrían permanecer sin ser detectados y usamos modelos de conteo simultáneo multinomial o binomial para estimar la abundancia, con el binomial como equivalente a un modelo de mezcla N con un solo sitio. Probamos el desempeño del modelo con simulaciones en un rango de probabilidades de detección, tamaños poblacionales, tasas de crecimiento, número de años, ocasiones de muestreo, y sitios. Después aplicamos nuestro método a tres especies de buitre que se encuentran en peligro crítico en Camboya para demostrar cuán aplicable es el modelo en el mundo real y para proporcionar las primeras estimaciones de abundancia para estas especies en Camboya. Nuestra nueva estrategia trabaja de mejor manera cuando se espera que los modelos existentes tengan un desempeño pobre (es decir, pocos sitios y una gran variación en la abundancia entre sitios) y si los individuos podrían moverse de un sitio a otro entre cada ocasión de muestreo. La estrategia tuvo un mejor desempeñó cuando hubo >8 ocasiones de muestreo y la probabilidad neta de detección fue alta (>0.5). Creemos que nuestra estrategia será especialmente útil para censos simultáneos en sitios de agregación, como los nidos. El método complementa las estrategias existentes para estimar la abundancia de individuos sin marcaje y es el primer método diseñado específicamente para conteos simultáneos.

Large-scale environmental degradation results in inequitable impacts to already impoverished communities: A case study from the floating villages of Cambodia.

Cambodian subsistence communities within the Tonle Sap Great Lake area rely on resource extraction from the lake to meet livelihood needs. These fishing communities-many of which consist of dwellings floating on the lake-face potentially profound livelihood challenges because of climate change and changing hydrology due to dam construction for hydroelectricity within the Mekong Basin. We conducted interviews across five village communities, with local subsistence fisher people in the Tonle Sap in 2015, and used thematic analysis methods to reveal a fishery system that is undergoing rapid ecological decline, with local fishing communities increasingly experiencing reductions in available fish stocks. As a result, over 100 000 people living in these communities are experiencing a direct loss of well-being and livelihood. We discuss these losses and consider their implications for the future viability of Cambodian floating village communities.

Investigating Vietnam's ornamental bird trade: implications for transmission of zoonoses.

Global wildlife trade is financially lucrative, frequently illegal and increases the risk for zoonotic disease transmission. This paper presents the first interdisciplinary study of Vietnam's illegal wild bird trade focussing on those aspects which may contribute to the transmission of diseases such as Highly Pathogenic Avian Influenza (HPAI) H5N1. Comparing January 2009 data with that of May 2007, we found a five-fold increase to 9,117 birds on sale in Hanoi. Ninety-five percent of Hanoian bird vendors appear unaware of trade regulations and across Vietnam vendors buy birds sourced outside of their province. Approximately 25% of the species common to Vietnam's bird trade are known to be HPAI H5N1 susceptible. The anthropogenic movement of birds within the trade chain and the range of HPAI-susceptible species, often traded alongside poultry, increase the risk Vietnam's bird trade presents for the transmission of pathogens such as HPAI H5N1. These results will assist in the control and monitoring of emerging zoonotic diseases and conservation of Southeast Asia's avifauna.