What an extraordinarily diverse group of birds! This magnificent book provides a panoramic yet penetrating overview of the reed warblers' intriguing. A fascinating read for bird watchers and bird ...researchers alike. British Birds Magazine and the British Trust for Ornithology awarded The Reed Warblers as the BB/BTO Best Bird Book of the Year 2012.
Self-awareness is an important concept in discussions of consciousness that has received increasing attention. To our knowledge, mirror self-recognition and self-awareness has not been studied in the ...white-browed laughing thrush Pterorhinus sannio. In our investigation, wild Pterorhinus sannio were presented with a self-recognition test known as the mirror self-recognition test (MSR). All birds performed four different displays in front of the mirror that we call "look around", "crouch", "jump to top of the mirror", and "shake the wings". These behaviours did not occur in the absence of the mirror. These behaviours typically are directed towards other individuals this suggest that P. sannio does not recognise itself in the mirror, and it does not have the capacity of self-awareness, at least not judged from the mark mirror test.
Populations of migratory songbirds in western Europe show considerable variation in population trends between species and regions. The demographic and environmental causes of these large‐scale ...patterns are poorly understood. Using data from Constant Effort mist‐netting studies, we investigated relationships between changes in abundance, adult survival and seasonal weather conditions among 35 western European populations of eight species of migratory warblers (Sylviidae). We used cross‐species and within‐species comparisons to assess whether annual variation in survival was correlated with weather conditions during passage or winter. We estimated survival using CJS mark‐recapture models accounting for variation in the proportion of transient individuals and recapture rates. Species wintering in the humid bioclimatic zone of western Africa had significantly higher annual survival probabilities than species wintering in the arid bioclimatic zone of Africa (the Sahel). Rainfall in the Sahel was positively correlated with survival in at least some populations of five species. We found substantially fewer significant relationships with indices of weather during the autumn and spring passage periods, which may be due to the use of broad‐scale indices. Annual population changes were correlated with adult survival in all of our study species, although species undergoing widespread declines showed the weakest relationships.
Anthropogenic noise is one of the fastest growing, globally widespread pollutants, affecting countless species worldwide. Despite accumulating evidence of the negative impacts of wind turbines on ...wildlife, little is known about how the noise they generate affects ecological systems. Songbirds may be susceptible to noise pollution due to their reliance on vocal communication and thus, in this field study, we examined how songbirds are affected by wind turbine noise. We broadcasted noise produced by one wind turbine in a migratory stopover site during the nonbreeding season. Throughout the study, we repeatedly monitored the acoustic environment and songbird community before, during, and after the noise treatments with passive acoustic monitoring and mist netting. We employed generalized linear mixed effects models to assess the impact of experimental noise treatment on birds behavior and likelihood ratio tests to compare models with variables of interest with null models. The daily number of birds in the presence of wind turbine noise decreased by approximately 30% compared with the before and after phases. This reduction had a significant spatial pattern; the largest decrease was closer to the speaker and on its downwind side, fitting measured sound propagation. Although we found no impact on species diversity, two out of three most common species showed clear avoidance behavior: 45% and 36% decrease in abundance for the lesser whitethroat (Sylvia curruca) and Sardinian warbler (Sylvia melanocephala momus), respectively. In the after phase, there were lingering effects on the lesser whitethroat. The age structure of the lesser whitethroat population was affected because only juvenile birds showed avoidance behavior. No difference in avoidance extent was found between migratory and nonmigratory species, but the impacts of displacement on migrants during stopover are especially troubling from a conservation perspective. Our results stress the need to address the impacts of noise pollution on wildlife when planning noise‐generating infrastructures, such as wind turbines, to allow for sustainable development without threatening already declining songbird populations.
Resumen
El ruido antropogénico es uno de los contaminantes con mayor crecimiento y distribución a nivel mundial, por lo que afecta a incontables especies en todo el mundo. A pesar de acumular evidencia sobre el impacto negativo que tienen las turbinas eólicas sobre la fauna, se sabe muy poco sobre cómo el ruido que generan afecta a los sistemas ecológicos. Las aves canoras pueden ser susceptibles a la contaminación sonora ya que dependen de la comunicación vocal y, por lo tanto, en este estudio de campo, analizamos cómo les afecta el sonido producido por las turbinas eólicas. Transmitimos ruido producido por una turbina en un punto de parada migratorio durante la temporada no reproductiva. Durante el estudio, monitoreamos repetidas veces el entorno acústico y la comunidad de aves canoras antes, durante y después de los tratamientos de ruido con monitoreo acústico pasivo y redes de niebla. Empleamos modelos de efectos lineales mixtos generalizados para evaluar el impacto del ruido experimental sobre el comportamiento de las aves y pruebas de probabilidad de proporción para comparar los modelos con variables de interés con los modelos nulos. El número diario de aves en la presencia del ruido de turbinas eólicas disminuyó aproximadamente un 30% en comparación con las fases de antes y después. Esta reducción tuvo un patrón espacial significativo: la mayor disminución ocurrió más cerca a la bocina y en el lado de sotavento, lo que se ajusta a la medida de la propagación del sonido. Aunque no encontramos impacto alguno sobre la diversidad de especies, dos de tres de las especies más comunes mostraron un comportamiento de evasión evidente: 45% y 36% de disminución en la abundancia de Sylvia curruca y Sylvia melanocephala momus, respectivamente. Durante la fase posterior al ruido, observamos efectos prolongados en S. curruca. La composición de edades de la población de S. curruca se vio afectada porque sólo los individuos juveniles mostraron un comportamiento de evasión. No encontramos una diferencia en el grado de evasión entre las especies migratorias y no migratorias, pero el impacto del traslado sobre las migrantes durante el punto de parada es de preocupación especial desde una perspectiva de conservación. Nuestros resultados acentúan la necesidad de abordar el impacto de la contaminación sonora sobre la fauna cuando se planean estructuras que producen ruido, como las turbinas eólicas, para permitir el desarrollo sustentable sin amenazar a las poblaciones de aves canoras que ya están en declive.
Efectos del ruido de turbinas eólicas sobre el comportamiento de las aves canoras durante la temporada no reproductiva
Aim: As global temperatures have increased, many species distributions have exhibited polewards shifts, a trend that is predicted to continue in future decades. However, the mechanisms underlying ...such shifts are not well understood. Here we quantify the impact of large-scale variation in temperature on reproductive output within a group of migratory birds to assess the potential for future range changes. Location: Western Europe. Methods: We use data from captures of 350,000 individual birds, collected under constant effort ringing protocols from 1994-2006, to estimate productivity (percentage of juveniles caught) for seven species of migrant warblers (family Sylviidae) breeding in Europe in relation to spring temperature and latitude by fitting generalized linear mixed models. Results: Productivity was highest at mid-latitudes for six of our seven study species and did not change significantly over the study period. Only one species (reed warbler, Acrocephalus scirpaceus) showed increased productivity at northern sites as expected. Six of the seven species also showed evidence for local adaptation, with productivity decreasing as temperatures diverged from the local mean. However, for three of these species the 'optimum' temperature was greater than the local mean temperature at the majority of sites. Main conclusions: These results indicate that latitudinal gradients in productivity are likely to influence large-scale abundance patterns, but that adaptation to local climate conditions has the potential to constrain the rate of northward range shifts in many species.
PDF
