scholarly journals Artificial night light and anthropogenic noise interact to influence bird abundance over a continental scale

2021 ◽  
Author(s):  
Ashley A. Wilson ◽  
Mark A. Ditmer ◽  
Jesse R. Barber ◽  
Neil H. Carter ◽  
Eliot T. Miller ◽  
...  
Keyword(s):  
Anthropogenic Noise ◽  
Bird Abundance ◽  
Continental Scale

scholarly journals Do Feeder Counts Reliably Indicate Bird Population Changes? 21 Years of Winter Bird Counts in Ontario, Canada

The Condor ◽  
2002 ◽  
Vol 104 (2) ◽  
pp. 255-270 ◽  
Author(s):  
Denis Lepage ◽  
Charles M. Francis
Keyword(s):  
North America ◽  
Sampling Error ◽  
Bird Species ◽  
Population Trends ◽  
Population Changes ◽  
Bird Abundance ◽  
Bird Populations ◽  
Continental Scale ◽  
Population Indices ◽  
High Consistency

Abstract Few monitoring programs in North America track bird populations at a continental scale during the winter, a critical stage of the life cycle for many species. To date, only Christmas Bird Counts (CBC) have been used to index bird abundance in winter across North America. We evaluated another continentwide program, Project FeederWatch (PFW), which monitors many bird species more intensively than CBC. PFW is a survey in which volunteers use standardized methods to count birds visiting feeders every two weeks from November through April. We compared population indices and trends from PFW and CBC data for 43 species in 3 regions of Ontario, Canada, over a 21-year period from 1976–1997. Annual population indices from PFW were significantly positively correlated with similar indices from CBC for about 80% of species for which annual variation in counts was substantially greater than sampling error. Log-linear population trends from both surveys were also well correlated, though the absolute value of the trend estimates tended to be higher for PFW. The high consistency between surveys suggests that both may be suitable for detecting population changes for many bird species in winter, especially irruptive species that show large annual fluctuations, and species with marked population trends. However, some species did not correspond between surveys, despite being measured fairly precisely, highlighting the value of having two independent surveys to corroborate patterns. Christmas Bird Counts have the advantage that they sample more species, but Project FeederWatch has a more consistent protocol and continues through the winter, allowing analysis of changes in populations through the winter. ¿Proveen los Conteos en Comederos Información Fidedigna sobre Cambios en las Poblaciones de Aves? 21 Años de Conteos Invernales de Aves en Ontario, Canadá Resumen. Pocos programas de monitoreo en América del Norte siguen a las poblaciones de aves a escala continental durante el invierno, cuando muchas especies pasan por una etapa crítica en su ciclo de vida. Hasta el presente, sólo los Conteos de Aves de Navidad (CAN) han sido usados para cuantificar la abundancia de aves en el invierno a lo largo de América del Norte. Nosotros evaluamos otro programa a nivel continental, el Proyecto de Observación de Comederos (POC), el cual sigue muchas especies de aves de modo más intenso que los CAN. El POC es un programa de muestreo en el cual voluntarios usan métodos estandarizados para contar las aves que visitan comederos, censándolas cada dos semanas entre noviembre y abril. Comparamos índices y tendencias poblacionales de los datos del POC y de los CAN para 43 especies en 3 regiones de Ontario, Canadá, a lo largo de un período de 21 años entre 1976 y 1997. Los índices poblacionales anuales del POC estuvieron positiva y significativamente correlacionados con índices similares de los CAN para alrededor del 80% de las especies, considerando aquellas para las que la variación anual en los conteos fue sustancialmente mayor que el error de muestreo. Las tendencias poblacionales de ambos muestreos, representadas de modo log-lineal, también estuvieron bien correlacionadas, aunque el valor absoluto de la tendencia estimada tendió a ser mayor para el POC. La alta consistencia entre los programas de muestreo sugiere que ambos pueden ser adecuados para detectar los cambios poblacionales de muchas especies de aves durante el invierno, especialmente para especies eruptivas que muestran grandes fluctuaciones anuales, y para aquellas con tendencias poblacionales marcadas. Sin embargo, algunas especies mostraron diferencias entre los programas de muestreo a pesar de haber sido medidas de modo bastante preciso, destacando el valor de tener dos métodos de muestreo independientes para corroborar los patrones. Los Conteos de Aves de Navidad tienen la ventaja de que muestrean más especies, pero el Proyecto de Observación de Comederos posee un protocolo más consistente y se prolonga a través del invierno, permitiendo analizar los cambios de las poblaciones a través de este período.

Summer bird abundance and distribution on set-aside fields on intensive arable farms in England

Ecography ◽  
2000 ◽  
Vol 23 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Ian G. Henderson ◽  
Juliet A. Vickery ◽  
Robert J. Fuller
Keyword(s):  
Bird Abundance ◽  
Abundance And Distribution

The Determinants of Entrepreneurship Development in Spatial Systems

2017 ◽  
Vol 13 ◽  
pp. 8-24
Author(s):  
Zbigniew Zioło
Keyword(s):  
Spatial Scales ◽  
Institutional Barriers ◽  
Entrepreneurship Development ◽  
Continental Scale ◽  
Spatial Systems ◽  
Business Conditions ◽  
Mutual Relations ◽  
Growth Shape ◽  
Strategic Goal

The processes of technological  progress create new opportunities for economic, social and cultural growth, shape new relations between economic  entities and their environment,  and influence changes in the determinants  of entrepreneurship development.  These processes vary significantly in certain geographic locations, characterised by an enormous  diversity of natural, social, economic and cultural structures. As a consequence, this creates different opportunities  and different conditions for the development of entrepreneurship in certain spatial scales, from the continental scale, through national and regional to local scales. The article presents complex conditions  for the development of entrepreneurship, highlights its limitations resulting from institutional  barriers, and the importance of knowing the mechanisms of mutual relations between spatial systems and the influence of control instruments. The quality of central and local government authorities is of particular significance here, which do not always properly use the mechanisms of rational business support. A serious barrier to the development of entrepreneurship is the low quality of social capital, manifested in a lack of trust in institutional authorities and reluctance to engage in entrepreneurship and business development. The conclusions point out that further research should be developed that will take into account changing business conditions, with a defined strategic goal of raising the quality and standard of living, international competitiveness of the country and products in different market categories.

scholarly journals Measuring compound flood potential from river discharge and storm surge extremes at the global scale

2020 ◽  
Vol 20 (2) ◽  
pp. 489-504 ◽  
Author(s):  
Anaïs Couasnon ◽  
Dirk Eilander ◽  
Sanne Muis ◽  
Ted I. E. Veldkamp ◽  
Ivan D. Haigh ◽  
...  
Keyword(s):  
Storm Surge ◽  
River Discharge ◽  
Flood Hazard ◽  
Joint Probability ◽  
Global Scale ◽  
Statistical Dependence ◽  
Dependence Structure ◽  
Meteorological Forcing ◽  
Continental Scale ◽  
Bivariate Dependence

Abstract. The interaction between physical drivers from oceanographic, hydrological, and meteorological processes in coastal areas can result in compound flooding. Compound flood events, like Cyclone Idai and Hurricane Harvey, have revealed the devastating consequences of the co-occurrence of coastal and river floods. A number of studies have recently investigated the likelihood of compound flooding at the continental scale based on simulated variables of flood drivers, such as storm surge, precipitation, and river discharges. At the global scale, this has only been performed based on observations, thereby excluding a large extent of the global coastline. The purpose of this study is to fill this gap and identify regions with a high compound flooding potential from river discharge and storm surge extremes in river mouths globally. To do so, we use daily time series of river discharge and storm surge from state-of-the-art global models driven with consistent meteorological forcing from reanalysis datasets. We measure the compound flood potential by analysing both variables with respect to their timing, joint statistical dependence, and joint return period. Our analysis indicates many regions that deviate from statistical independence and could not be identified in previous global studies based on observations alone, such as Madagascar, northern Morocco, Vietnam, and Taiwan. We report possible causal mechanisms for the observed spatial patterns based on existing literature. Finally, we provide preliminary insights on the implications of the bivariate dependence behaviour on the flood hazard characterisation using Madagascar as a case study. Our global and local analyses show that the dependence structure between flood drivers can be complex and can significantly impact the joint probability of discharge and storm surge extremes. These emphasise the need to refine global flood risk assessments and emergency planning to account for these potential interactions.

scholarly journals A susceptibility-based rainfall threshold approach for landslide occurrence

2019 ◽  
Vol 19 (4) ◽  
pp. 775-789 ◽  
Author(s):  
Elise Monsieurs ◽  
Olivier Dewitte ◽  
Alain Demoulin
Keyword(s):  
Landslide Susceptibility ◽  
Rainfall Threshold ◽  
Exceedance Probability ◽  
Equal Weight ◽  
Antecedent Rainfall ◽  
Rainfall Thresholds ◽  
Landslide Occurrence ◽  
Continental Scale ◽  
Satellite Rainfall ◽  
Rainfall Estimates

Abstract. Rainfall threshold determination is a pressing issue in the landslide scientific community. While major improvements have been made towards more reproducible techniques for the identification of triggering conditions for landsliding, the now well-established rainfall intensity or event-duration thresholds for landsliding suffer from several limitations. Here, we propose a new approach of the frequentist method for threshold definition based on satellite-derived antecedent rainfall estimates directly coupled with landslide susceptibility data. Adopting a bootstrap statistical technique for the identification of threshold uncertainties at different exceedance probability levels, it results in thresholds expressed as AR = (α±Δα)⋅S(β±Δβ), where AR is antecedent rainfall (mm), S is landslide susceptibility, α and β are scaling parameters, and Δα and Δβ are their uncertainties. The main improvements of this approach consist in (1) using spatially continuous satellite rainfall data, (2) giving equal weight to rainfall characteristics and ground susceptibility factors in the definition of spatially varying rainfall thresholds, (3) proposing an exponential antecedent rainfall function that involves past daily rainfall in the exponent to account for the different lasting effect of large versus small rainfall, (4) quantitatively exploiting the lower parts of the cloud of data points, most meaningful for threshold estimation, and (5) merging the uncertainty on landslide date with the fit uncertainty in a single error estimation. We apply our approach in the western branch of the East African Rift based on landslides that occurred between 2001 and 2018, satellite rainfall estimates from the Tropical Rainfall Measurement Mission Multi-satellite Precipitation Analysis (TMPA 3B42 RT), and the continental-scale map of landslide susceptibility of Broeckx et al. (2018) and provide the first regional rainfall thresholds for landsliding in tropical Africa.

scholarly journals Toward a broader characterization of anthropogenic noise and its effects on wildlife

2014 ◽  
Vol 26 (2) ◽  
pp. 328-333 ◽  
Author(s):  
S. A. Gill ◽  
J. R. Job ◽  
K. Myers ◽  
K. Naghshineh ◽  
M. J. Vonhof
Keyword(s):  
Anthropogenic Noise
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