Ozone pollution threatens bird populations to collapse:an imminent ecological threat?

While bird populations are declining,the factors associated with this decline are unclear.Based on laboratory experiments,air pollution has long been recognized as a factor causing oxidative stress and adversely aff ecting bird health.Recently,studies employing an epidemiological approach have reported signifi cant declines in avian populations in Central Europe and the United States due to air pollution,and ozone in particular.We advocate that urgent actions are needed to mitigate these eff ects,which threaten biodiversity and environmental health,and propose a series of measures which can enlighten the path toward mitigating air pollution eff ects on avian populations.

Influence of land use change on the waterbird community of Sihwa Lake,Republic of Korea

Background:Land use and development alter mudflat and wetland habitat availability,although mudflats and wetlands provide important stopover habitats for shorebirds during the spring and autumn migrations and support communities of ducks and geese during the winter months in the Republic of Korea.This study investigated land use changes around Sihwa Lake(Republic of Korea)and evaluated the effect of these changes on waterbird community characteristics.Methods:We conducted a land-use-change analysis at the medium-resolution level using land cover maps for 2001,2007,2009,and 2014.Also,a tidal stream survey was conducted in Sihwa Lake and the surrounding reclaimed mudflats every season for 10 years(2003-2012)to identify the seasonal and interannual variations in waterbird species composition.To determine the total annual waterbird species and population counts,species diversity index,and interspecies variations,a TRIM(trends and indices for monitoring data)analysis was used.Results:Wetland area decreased more than 10%while agricultural land,barren land,and grassland area increased more than 10%due to continuous reclamation activities around Sihwa Lake.Barren land later turned into agricultural land or other land use.Sixty-three species and 566,623 individuals were recorded.The number of species,population size,and species diversity index by year and by species showed decreasing trends that were more marked in spring and summer.Furthermore,seasonal and annual variations in waterbird species composition showed decreasing trends in dabbling ducks,herons,grebes,and shorebirds but diving ducks displayed increasing trends.In particular,shorebirds were reduced to a greater extent than other waterbird species because of the reduction and simplification of the intertidal zone,and shallow waters caused by reclamation and road construction.Conclusions:Increased development and construction around Sihwa Lake has altered migratory shorebird populations with a general decline in species diversity and population size.The greatest decline was observed in wading birds,while diving duck populations showed increasing trends.

Variation in abundance and habitat relationship of three understory insectivorous birds in a disturbed landscape of Neotropical dry forest of Colombia

Background:Evaluating relationships between avian populations and their habitat is important for understanding the biology of these species and for management decisions that improve the effectiveness of restoration practices.We investigated how habitat variation along a disturbance gradient affected the abundance of three insectivorous bird species,White-bellied Antbird(Myrmeciza longipes),Barred Antshrike(Thamnophilus doliatus),and Pale-breasted Spinetail(Synallaxis albescens)in a Neotropical dry forest remnant in central Colombia.Methods:The study area,which is located in Magdalena Valley,is under ecological restoration after the construction of the“El Quimbo”hydroelectric dam,with a gradient of habitat conditions,from relatively advanced secondary growth to recently disturbed areas.We conducted bird surveys and quantified the habitat conditions from June 2018 to June 2019.We compared the relative abundance of the birds among the three zones with increasing disturbance and modeled the relationship between the bird abundance with the micro-and landscape-habitat conditions,with Poisson generalized linear model regression.Results:The relative abundance of the three bird species varied according to the habitat features and disturbance level.The abundance of White-bellied Antbirds was higher in forests and thickets than shrubland fragments;Barred Antshrike was more abundant in shrubland and thickets than in forest fragments,and Pale-breasted Spinetail had the highest abundance in shrubland and the lowest in forest fragments.The abundance of both White-bellied Antbird and Pale-breasted Spinetail did not differ among zones with different levels of disturbance,while the abundance of Barred Antshrike decreased in zones with more disturbance.Conclusions:There were significant differences in the habitat relationships of the three understory insectivorous species along the disturbance gradient,although these species were within the same trophic group.These bird species preferred different stages of habitat succession and responded to different habitat and landscape features.Increasing forest fragment areas and decreasing the amount of edge would be useful restoration priorities for these and other similar avian species in this study area.

Do Birds Return to Agricultural Landscapes through Adoption of Natural Farming Practices? A Comparison of Natural Farming vs. Chemical Farming in Andhra Pradesh

The global decline in farmland bird populations in India is often ignored. The overuse of agrochemicals in farming is the root cause of all these catastrophic results. There is ample evidence in the literature that transitioning to agroecological practices may reverse this trend. We anticipated that the bird population visiting natural farming-Andhra Pradesh Community managed Natural Farming (APCNF), a novel farming approach popular in India, will increase. The study used nested design to compare the number of bird visitations in natural farming versus chemical farming to determine whether natural farming can enhance the bird numbers and diversity. Furthermore, we analyzed the bird species visits to natural and chemical farms in different agroecological zones in Andhra Pradesh, the southernmost state of India. We used the point count survey approach to count the birds on comparable farms. MANOVA and non-parametric analysis are used to examine the findings. The bird species were ranked using a Likert scale. The results show that the average bird population visiting natural vs. chemical farms varies significantly at the 0.05 level of significance, and the bird species visiting both natural farming fields and chemical farms varies between geographies and time interval.